SECTION Anti-Lock Brake System (ABS) and Stability Control

Transcription

1 i Anti-Lock Brake System (ABS) and Stability Control i SECTION Anti-Lock Brake System (ABS) and Stability Control CONTENTS PAGE DIAGNOSIS AND TESTING Anti-Lock Control Principles of Operation ABS with Traction Control and Electronic Stability Control (ESC) Stability Control Sensors Steering Wheel Rotation Sensor Inspection and Verification DTC Charts Symptom Chart Pinpoint Tests

2 Anti-Lock Brake System (ABS) and Stability Control DIAGNOSIS AND TESTING Anti-Lock Control Special Tool(s) Backprobe Pins POM6411 or equivalent Flex Probe Kit 300-NUD105-R025DE or equivalent Fluke 77-IV Digital Multimeter FLU77-4 or equivalent Rotunda Active Wheel Speed Sensor Tester 105-R0110 Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Principles of Operation ABS with Traction Control and Electronic Stability Control (ESC) The ABS module with traction control manages anti-lock braking to maintain vehicle control and performs additional functions specific to traction control and Electronic Stability Control (ESC). ABS Operation When the ignition switch is in the RUN position, the ABS module does a preliminary electrical check. At approximately 20 km/h (12 mph), the hydraulic pump motor is turned on for approximately one-half second. During this time a buzzing or humming noise may be heard and a vibration may be felt in the brake pedal. This is a normal condition. Any malfunction of the ABS disables the stability assist and illuminates the ABS warning indicator. However, the power-assist braking system functions normally. The ABS module monitors and compares the rotational speed of each wheel. Wheel speeds are measured by the wheel speed sensor, which electrically senses each tooth of the sensor ring as it passes through the magnetic field of the sensor. When the ABS module detects an impending wheel lock, the ABS module commands the hydraulic pump motor on and commands the Hydraulic Control Unit (HCU) to open and close the appropriate solenoid valves to

3 Anti-Lock Brake System (ABS) and Stability Control modulate the brake pressure to the individual brake caliper(s). Once the affected wheel(s) returns to the desired speed, the ABS module commands the HCU to return the solenoid valves to their normal position and normal base brake operation is restored. The ABS module must be configured when a new ABS module is installed. Electronic Brake Distribution (EBD) On initial application of the brake pedal, full pressure is applied to the rear brakes. The ABS module then uses wheel speed input to calculate an estimated rate of deceleration. Once vehicle deceleration exceeds a predetermined threshold, the ABS module closes the appropriate isolation valves in the HCU to hold the rear brake pressure constant while allowing the front brake pressure to build. This creates a balanced braking condition between the front and rear wheels and minimizes the chance of rear wheel lockup during hard braking. As the vehicle decelerates, the valves are opened to increase the rear brake pressure in proportion to the front brake pressure. A slight bump sensation may be felt in the brake pedal when Electronic Brake Distribution (EBD) is active. EBD will be disabled if DTCs are present for 2 or more wheel speed sensors. When EBD is disabled, the yellow ABS warning indicator and the sliding-car icon will be illuminated. Traction Control When the drive wheels lose traction and begin to spin, with vehicle speed under 100 km/h (62 mph), the ABS module commands the hydraulic pump motor on and commands the HCU to open and close the appropriate solenoid valves to modulate the brake pressure to the brake caliper(s) while simultaneously sending a request to the PCM over the High Speed Controller Area Network (HS-CAN) bus to reduce engine torque to maintain vehicle traction. The PCM accomplishes this with incremental timing changes and fewer fuel injector pulses until the ABS module ends the request. The request ends when the driven wheel speed returns to the desired speed. After the vehicle speed exceeds 100 km/h (62 mph), traction control is accomplished using only the PCM torque control function. The traction control system can be deactivated by pressing the traction control switch in the instrument panel. Electronic Stability Control (ESC) The Electronic Stability Control (ESC) system constantly monitors the vehicle motion relative to the intended course. This is done by using sensors to compare the steering input and the yaw rate sensor with that of the actual vehicle motion. The ESC system monitors information from the Throttle Position (TP) sensor, the steering wheel rotation sensor (steering wheel angle and rate of change) and a yaw rate sensor which is integral to the Restraints Control Module (RCM) and measures changes in vehicle direction. If the ESC system determines from all these inputs that the vehicle is unable to travel in the intended direction, the system adjusts the brake torque at specific wheels in response to direct measurement of the vehicle motion and reduces engine torque to allow the vehicle to follow the intended course. Traction Control Switch The traction control switch is hardwired to the Instrument Panel Cluster (IPC). The IPC communicates switch status to the ABS module via the HS-CAN bus. The traction control switch allows the driver to control use of the traction control and ESC systems. Traction control system status is indicated by the sliding-car icon in the IPC. The system will automatically restore to full functionality when the ignition switch is cycled from OFF to RUN. Stability Control Sensors The stability control sensors for the ESC system include the yaw rate sensor, lateral accelerometer and longitudinal accelerometer. The sensors are housed in the RCM which sends sensor information to the ABS module over a dedicated Controller Area Network (CAN) bus. If any of the sensors are defective, a new RCM must be installed. The yaw rate sensor measures the relative vehicle motion about the vertical axis through its center of gravity. The lateral accelerometer measures the acceleration that corresponds to the force involved when the vehicle moves sideways. The longitudinal accelerometer measures the acceleration corresponding to the force involved when the vehicle moves forward and rearward in the horizontal plane, along the centerline of the vehicle front and rear wheels. Lateral acceleration has 2 forms. The first is the centrifugal acceleration that occurs when the vehicle travels around in a circle. The second is the acceleration due to gravity. On level ground there is no contribution from this acceleration. However, if the vehicle is parked sideways on a bank or incline, the sensor measures some lateral acceleration due to gravity, even though the vehicle is not moving. Steering Wheel Rotation Sensor The steering wheel rotation sensor measures the rate of rotation of the steering wheel by monitoring the steering wheel rotation ring as it passes through the sensor gap. The steering wheel rotation sensor uses 2 signal lines to transmit information to the ABS module about whether the steering wheel is being turned left or right and how far it is being turned. The steering wheel rotation sensor does not indicate the absolute position of the steering wheel relative to straight-ahead. The stability assist system learns this position by comparing the steering wheel position with other signals and storing the position it has learned. The stability assist system confirms this position and modifies it as necessary during every new driving cycle. ABS Module Calibration When a new ABS module, HCU, RCM or steering wheel rotation sensor is installed, the ABS module must be calibrated. The calibration procedure is required for the ABS module to learn the "zero-position" of the various ESC sensors and components. If a DTC is logged for any component of the ESC system, the DTC must be repaired and then cleared before carrying out the calibration procedure. The need to calibrate the ABS module is also indicated by the sliding-car icon in the IPC flashing once every 2 seconds. The indicator flashes after clearing the DTCs that are associated with the ESC systems. To calibrate the ABS module, carry out the IVD Initialization sequence using the scan tool. When carrying out the calibration procedure, the following criteria must be met. The vehicle must be on a level surface.

4 Anti-Lock Brake System (ABS) and Stability Control The vehicle must not be moving. The transmission must be in NEUTRAL. The brake pedal must be applied. If a DTC is retrieved after calibration, refer to the ABS Module DTC Chart in this section. ABS Module Configuration When a new ABS module is installed on vehicles equipped with a 4.6L engine, it must be configured. Refer to Programmable Module Installation (PMI) in Section Vehicles equipped with a 4.0L or a 5.4L engine do not require PMI. Inspection and Verification 1. Verify the customer concern. 2. Verify the stoplamps operate correctly by pressing and releasing the brake pedal with the ignition switch in the OFF position. If the stoplamps do not operate correctly, refer to Section If the stoplamps operate correctly, proceed to the next step. 3. Verify the base brake system operates correctly. If any concerns are present, address them before continuing with any ABS concerns. Refer to Section If the base brake system operates correctly, proceed to the next step. 4. Visually inspect for obvious signs of mechanical or electrical damage. Visual Inspection Chart Mechanical Base brake system Hydraulic Control Unit (HCU) Steering wheel rotation sensor ring Tire pressure Tire size or mismatched tires Wheel speed sensor ring Electrical ABS module Battery Junction Box (BJB) fuse(s): 8 (40A) 10 (30A) Smart Junction Box (SJB) fuse 34 (5A) Brake Pedal Position (BPP) switch Restraints Control Module (RCM) Traction control switch Steering wheel rotation sensor Wheel speed sensor Wiring, terminals or connectors 5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step. 6. NOTE: Make sure to use the latest scan tool software release. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC). 7. NOTE: The Vehicle Communication Module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. refer to Section , Power To The Scan Tool, to diagnose no power to the scan tool. 8. If the scan tool does not communicate with the vehicle: verify the ignition is ON. verify the scan tool operation with a known good vehicle. refer to Section to diagnose no response from the PCM. 9. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to Section If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs). 10. Clear the CMDTCs and carry out the self-test diagnostics for the ABS module and the IPC. 11. If the DTCs retrieved are related to the concern, go to the ABS Module DTC Chart. For all other DTCs, refer to Section If no DTCs related to the concern are retrieved, GO to Symptom Chart.

5 Anti-Lock Brake System (ABS) and Stability Control DTC Charts ABS Module DTC Chart DTC Description Action B1317 Battery Voltage High GO to Pinpoint Test A. B1318 Battery Voltage Low GO to Pinpoint Test A. B1342 ECU is Faulted NOTE: If other DTCs are present, REPAIR them before installing a new component. CLEAR the DTCs. CARRY OUT the self-test and RETRIEVE the DTCs. If DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. B2477 Module Configuration Failure For vehicles equipped with a 4.6L engine, CONFIGURE the ABS module. REFER to Programmable Module Installation (PMI) in Section CLEAR the DTCs. Using the scan tool, CARRY OUT the IVD Initialization sequence. REPEAT the self-test. If DTC B2477 is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. REPEAT the self-test. For all other vehicles, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. REPEAT the selftest. B2900 VIN Mismatch GO to Pinpoint Test M. C1095 ABS Hydraulic Pump Motor Circuit Failure GO to Pinpoint Test C. C1096 ABS Hydraulic Pump Motor Circuit Open GO to Pinpoint Test C. C1115 ABS Power Relay Output Short Circuit to Battery NOTE: If other DTCs are present, REPAIR them before installing a new component. C1145 RF Wheel Speed Sensor Input Circuit Failure GO to Pinpoint Test D. C1155 LF Wheel Speed Sensor Input Circuit Failure GO to Pinpoint Test D. C1165 RR Wheel Speed Sensor Input Circuit Failure GO to Pinpoint Test D. C1175 LR Wheel Speed Sensor Input Circuit Failure GO to Pinpoint Test D. CLEAR all DTCs. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. RETRIEVE the DTCs. If DTC C1115 is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1185 ABS Power Relay Output Circuit Failure NOTE: If other DTCs are present, REPAIR them before installing a new component. C1194 ABS Outlet Valve Coil LF Circuit Failure GO to Pinpoint Test B. C1198 ABS Inlet Valve Coil LF Circuit Failure GO to Pinpoint Test B. C1210 ABS Outlet Valve Coil RF Circuit Failure GO to Pinpoint Test B. C1214 ABS Inlet Valve Coil RF Circuit Failure GO to Pinpoint Test B. C1222 Wheel Speed Mismatch GO to Pinpoint Test E. C1233 LF Wheel Speed Input Signal Missing GO to Pinpoint Test E. C1234 RF Wheel Speed Input Signal Missing GO to Pinpoint Test E. C1235 RR Wheel Speed Input Signal Missing GO to Pinpoint Test E. C1236 LR Wheel Speed Input Signal Missing GO to Pinpoint Test E. CLEAR all DTCs. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. RETRIEVE any DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

6 Anti-Lock Brake System (ABS) and Stability Control ABS Module DTC Chart (Continued) DTC Description Action C1242 ABS Outlet Valve Coil LR Circuit Failure GO to Pinpoint Test B. C1246 ABS Outlet Valve Coil RR Circuit Failure GO to Pinpoint Test B. C1250 ABS Inlet Valve Coil LR Circuit Failure GO to Pinpoint Test B. C1254 ABS Inlet Valve Coil RR Circuit Failure GO to Pinpoint Test B. C1277 Steering Wheel Angle 1 and 2 Circuit Failure GO to Pinpoint Test F. C1278 Steering Wheel Angle 1 and 2 Signal Faulted GO to Pinpoint Test F. C1279 Yaw Rate Sensor Circuit Failure This DTC indicates a concern with the yaw rate sensor which is integral to the Restraints Control Module (RCM). REFER to Section B to diagnose all the RCM DTCs. If no RCM DTCs are present, GO to Pinpoint Test K. C1280 Yaw Rate Sensor Signal Fault This DTC indicates a concern with the yaw rate sensor which is integral to the Restraints Control Module (RCM). REFER to Section B to diagnose the RCM. If a new yaw rate sensor is needed, a new RCM must be installed. C1281 Lateral Accelerometer Circuit Failure This DTC indicates a concern with the yaw rate sensor which is integral to the Restraints Control Module (RCM). REFER to Section B to diagnose all the RCM DTCs. If no RCM DTCs are present, GO to Pinpoint Test K. C1282 Lateral Accelerometer Signal Fault This DTC indicates a concern with the lateral acceleration sensor which is integral to the RCM. REFER to Section B to diagnose the RCM. If a new lateral acceleration sensor is needed, a new RCM must be installed. C1288 Pressure Transducer Main/Primary Input Circuit Failure GO to Pinpoint Test H. C1327 Hydraulic Base Brake Failure CHECK brake fluid level and ADJUST as needed. CLEAR DTC and REPEAT self-test. If DTC C1327 is retrieved again, REFER to Section to diagnose brake fluid level switch. C1329 ABS Outlet Valve Coil RF Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1330 ABS Outlet Valve Coil LR Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1331 ABS Outlet Valve Coil RR Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1332 ABS Outlet Valve Coil LF Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1333 ABS Inlet Valve Coil LR Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1334 ABS Inlet Valve Coil LF Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1335 ABS Inlet Valve Coil RF Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

7 Anti-Lock Brake System (ABS) and Stability Control ABS Module DTC Chart (Continued) DTC Description Action C1336 ABS Inlet Valve Coil RR Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1404 Traction Control Valve Rear Circuit Failure GO to Pinpoint Test B. C1410 Traction Control Valve LF Circuit Failure GO to Pinpoint Test B. C1446 Brake Switch Circuit Failure GO to Pinpoint Test I. C1527 Traction Control Rear Valve Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1528 Traction Control LF Valve Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1530 C1531 Dynamic Stability Control RF Valve Circuit Excessive Temperature Dynamic Stability Control LF Valve Circuit Excessive Temperature CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. CLEAR all DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1730 Reference Voltage Out of Range (+5 V) If any other DTCs are present, diagnose those DTCs first. CLEAR all DTCs. DRIVE the vehicle. RETRIEVE DTCs. If the DTC is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. C1957 Dynamic Stability Control Valve RF Circuit Failure GO to Pinpoint Test B. C1958 Dynamic Stability Control Valve LF Circuit Failure GO to Pinpoint Test B. C1963 Stability Control Inhibit Warning GO to Pinpoint Test G. C1991 Module Calibration Failure NOTE: REPAIR all other DTCs prior to diagnosing this DTC. GO to Pinpoint Test J. U0073 Control Module Communication Bus Off REFER to Section to diagnose the High Speed Controller Area Network (HS-CAN) bus. U0074 Control Module Communication Bus B Off GO to Pinpoint Test K. U0115 Lost Communication with ECM/PCM - Secondary (SPCM) REFER to Section to diagnose the HS-CAN bus. U0155 Lost Communication with Instrument Panel Cluster (IPC) Control Module REFER to Section to diagnose the HS-CAN bus. U2050 Application Present CLEAR the DTCs. REPEAT the self-test. RETRIEVE the DTCs. If DTC U2050 is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTC. REPEAT the self-test. U2051 One or More Calibration Files Missing/Corrupt CLEAR the DTCs. CARRY OUT the ABS module self-test. RETRIEVE and RECORD any DTCs. If DTC U2051 is retrieved again, INSTALL a new ABS module. REFER to Anti- Lock Brake System (ABS) Module in this section. CLEAR the DTC. REPEAT the self-test.

8 Anti-Lock Brake System (ABS) and Stability Control Symptom Chart Symptom Chart Condition Possible Sources Action communication with the ABS module Wiring, terminals or connectors ABS module The ABS warning indicator is always/never on The red brake warning indicator is always/ never on The stability/traction control indicator (sliding-car icon) is always/never on The stability/traction control indicator (sliding-car icon) is flashing at all times The traction control system cannot be disabled/enabled Wiring, terminals or connectors ABS module Instrument Panel Cluster (IPC) Wiring, terminals or connectors Parking brake switch Brake fluid level switch (part of the master cylinder) IPC ABS module PCM IPC Wiring, terminals or connectors Traction control switch NOTE: It is normal for the indicator to flash during a traction control event. ABS module not configured ABS/ESC system not initialized Fuse Wiring, terminals or connectors Traction control switch PCM The traction control system is inoperative Traction control system is turned off Traction control system is not configured Fuse Wiring, terminals or connectors ABS wheel speed sensor fault High Speed Controller Area Network (HS- CAN) bus fault PCM IPC Traction control switch ABS false activation, ABS too sensitive or ABS activates on a normal stop REFER to Section to diagnose the no communication concern. REFER to Section to continue diagnosis of the warning indicator. REFER to Section to continue diagnosis of the warning indicator. REFER to Section to continue diagnosis of the warning indicator. RETRIEVE and RECORD all ABS module DTCs and GO to the ABS Module DTC Chart. GO to Pinpoint Test L. GO to Pinpoint Test L. DTCs present in the ABS module CARRY OUT the ABS module self-test. RETRIEVE and RECORD the ABS module DTCs. GO to the ABS Module DTC Chart. Brake pads Brake calipers and/or guide pins Parking brake shoes out of adjustment (dragging) Vehicle pulls during braking Brake pads Brake discs Brake calipers and/or guide pins Wheel speed sensor One or more wheel(s) lock up Brake pads Brake calipers and/or guide pins ELIMINATE the base brake system as the cause of the problem. REFER to Diagnosis and Testing in Section CHECK and if necessary, ADJUST the parking brake shoes. REFER to Section Front wheel speed sensor rings INSPECT both front wheel speed sensor rings for damaged teeth. CHECK the wheel speed sensor gap. Wheel speed sensors GO to Pinpoint Test E. REFER to Section to diagnose the base braking system. ELIMINATE the base brake system as the cause of the problem. REFER to Diagnosis and Testing in Section

9 Anti-Lock Brake System (ABS) and Stability Control Symptom Chart (Continued) Condition Possible Sources Action Parking brake shoes out of adjustment (dragging) Hydraulic outlet (dump) valve Leaky inlet (isolation) valve during ABS (soft) Brake tubes are installed in the wrong locations Soft/excessive brake pedal travel Air in brake system Brake calipers and/or guide pins Brake flexible hose Brake master cylinder Brake pads Brake pedal Inlet (isolation) valve or hydraulic outlet (dump) valve Leaky inlet (isolation) valve during ABS applications (soft) CHECK and if necessary, ADJUST the parking brake shoes. REFER to Section BLEED the HCU. REFER to Brake System Bleeding in Section TEST the system for normal operation. If the symptom returns, INSTALL a new Hydraulic Control Unit (HCU). REFER to Hydraulic Control Unit (HCU) in this section. VERIFY the correct installation of each brake tube and REPAIR as needed. ELIMINATE the base brake system as the cause of the problem. REFER to Diagnosis and Testing in Section BLEED the HCU. REFER to Brake System Bleeding in Section TEST the system for normal operation. If the symptom returns, INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) in this section. Pinpoint Tests Pinpoint Test A: DTC B1317 or B1318 Refer to Wiring Diagrams Cell 42, Vehicle Dynamic Systems for schematic and connector information. rmal Operation The operating voltage required to supply the ABS module, hydraulic pump and isolation valves is in a range between 10 and 16 volts. Fused battery voltage is supplied to the ABS module by Battery Junction Box (BJB) fuse 8 (40A) along circuit SBB08 (VT/RD) and BJB fuse 10 (30A) along circuit SBB10 (YE/RD). Fused ignition voltage is supplied to the ABS module by Smart Junction Box (SJB) fuse 34 (5A) along circuit CBP34 (VT/ BN). Ground is supplied to the ABS module along circuit GD120 (BK/GN). There are 2 ground circuits (one for the ABS module and one for the ABS pump motor), and both share the same circuit number and wire color. DTC B1317 (Battery Voltage High) If the voltage supplied to the ABS module exceeds 16 volts during the ABS module self-test or normal operation, with vehicle speed greater than 5 km/h (3 mph), DTC B1317 will be set. DTC B1318 (Battery Voltage Low) If the voltage supplied to the ABS module falls below 10 volts during the ABS module self-test or normal operation, with vehicle speed greater than 5 km/h (3 mph), DTC B1318 will be set. This pinpoint test is intended to diagnose the following: Wiring, terminals or connectors Vehicle charging system ABS module PINPOINT TEST A: DTC B1317 OR B1318 NOTE: DTC B1317 or B1318 can be set if the vehicle has been recently jump started, the battery has been recently charged or the battery has been discharged. The battery may become discharged due to excessive load(s) on the charging system from aftermarket accessories or if the battery has been left unattended with the accessories on. NOTE: Carry out a thorough inspection and verification before proceeding with the pinpoint test. Refer to Inspection and Verification in this section. A1 RETRIEVE ALL CMDTCs Test Step Result / Action to Take

10 Anti-Lock Brake System (ABS) and Stability Control A1 A2 A3 PINPOINT TEST A: DTC B1317 OR B1318 (Continued) Test Step RETRIEVE ALL CMDTCs (Continued) Enter the following diagnostic mode on the scan tool: Self Test All CMDTCs. Is DTC B1317 or B1318 present in one or more modules AND DTC P0563, P0620, P0625, P0626 or P065B present in the PCM? CHECK BATTERY CONDITION Refer to Section and carry out the Battery Condition Test. Does the battery pass the condition test? CHECK THE CHARGING SYSTEM VOLTAGE NOTE: Do not allow the engine rpm to increase above 2,000 rpm while performing this step or the generator may self excite and result in default charging system output voltage. If engine rpm has gone above 2,000 rpm, shut the vehicle OFF and restart the engine before performing this step. Result / Action to Take REFER to Section for diagnosis of the battery and charging system. GO to A2. If the battery passed the condition test but required a recharge, REFER to Section to diagnose the charging system. CLEAR all Continuous Memory Diagnostic Trouble Codes (CMDTCs). TEST the system for normal operation. If the battery passed the condition test and did not require a recharge, GO to A3. INSTALL a new battery. CLEAR all CMDTCs. TEST the system for normal operation. Start the engine. Measure the voltage of the battery: For DTC B1317, turn off all accessories and run the engine at 1,500 rpm for a minimum of 2 minutes. For DTC B1318, turn on headlights and HVAC fan on high and run engine at 1,500 rpm for a minimum of 2 minutes. A4 Is the battery voltage between volts? CHECK THE VOLTAGE TO THE ABS MODULE Disconnect: ABS Module C135. Measure the voltage between ground and: ABS module C135-25, circuit SBB10 (YE/RD), harness side. ABS module C135-1, circuit SBB08 (VT/RD), harness side. ABS module C135-30, circuit CBP34 (VT/BN), harness side. For DTC B1318, GO to A4. For DTC B1317, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. Using the scan tool, CARRY OUT the IVD Initialization sequence. CLEAR all CMDTCs. REPEAT the self-test. REFER to Section to diagnose the charging system. CLEAR all CMDTCs. TEST the system for normal operation. GO to A5. If the voltage at pin 25 is less than 10 volts, VERIFY BJB fuse 10 (30A) is OK. If the voltage at pin 1 is less than 10 volts, VERIFY BJB fuse 8 (40A) is OK. If the voltage at pin 30 is less than 10 volts, VERIFY SJB fuse 34 (5A) is OK. If any fuse is not OK, REFER to the Wiring Diagrams manual to identify the possible causes of the circuit short. If fuses are OK, REPAIR the

11 Anti-Lock Brake System (ABS) and Stability Control A4 PINPOINT TEST A: DTC B1317 OR B1318 (Continued) CHECK THE VOLTAGE TO THE ABS MODULE (Continued) A5 Are the voltages greater than 10 volts? CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN Measure the resistance between ground and: ABS module C135-38, circuit GD120 (BK/GN), harness side. ABS module C135-13, circuit GD120 (BK/GN), harness side. affected circuit(s). CLEAR the DTCs. REPEAT the selftest. A6 Are the resistances less than 5 ohms? CHECK FOR CORRECT ABS MODULE OPERATION Check ABS module C135 for: corrosion. pushed-out pins. spread terminals. Connect: ABS Module C135. Make sure the connector is fully seated and locked, then operate the system and verify the concern is still present. Is the concern still present? GO to A6. REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test. INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector or a malfunctioning charging system. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. Pinpoint Test B: DTCs C1194, C1198, C1210, C1214, C1242, C1246, C1250, C1254, C1404, C1410, C1957 and C1958 Refer to Wiring Diagrams Cell 42, Vehicle Dynamic Systems for schematic and connector information. rmal Operation The operating voltage required to operate the valves in the Hydraulic Control Unit (HCU) is in a range between 10 and 16 volts. Fused battery voltage is supplied to the ABS module by Battery Junction Box (BJB) fuse 8 (40A) along circuit SBB08 (VT/RD) and BJB fuse 10 (30A) along circuit SBB10 (YE/RD). Fused ignition voltage is supplied to the ABS module by Smart Junction Box (SJB) fuse 34 (5A) along circuit CBP34 (VT/ BN). Ground is provided to the ABS module along circuit GD120 (BK/GN). There are 2 ground circuits (one for the ABS module and one for the ABS pump motor), and both share the same circuit number and wire color.

12 Anti-Lock Brake System (ABS) and Stability Control DTC Description C1194 ABS Outlet Valve Coil LF Circuit Failure C1198 ABS Inlet Valve Coil LF Circuit Failure C1210 ABS Outlet Valve Coil RF Circuit Failure C1214 ABS Inlet Valve Coil RF Circuit Failure C1242 ABS Outlet Valve Coil LR Circuit Failure C1246 ABS Outlet Valve Coil RR Circuit Failure C1250 ABS Inlet Valve Coil LR Circuit Failure C1254 ABS Inlet Valve Coil RR Circuit Failure C1404 Traction Control Valve Rear Circuit Failure C1410 Traction Control Valve LF Circuit Failure C1957 Dynamic Stability Control Valve RF Circuit Failure C1958 Dynamic Stability Control Valve LF Circuit Failure Fault Trigger Conditions If, during normal operation or the on-demand self test, the ABS module detects an open circuit, short to ground or battery, or a defective trigger circuit, the appropriate DTC will be set. This pinpoint test is intended to diagnose the following: Wiring, terminals or connectors Vehicle charging system ABS module PINPOINT TEST B: DTCs C1194, C1198, C1210, C1214, C1242, C1246, C1250, C1254, C1404, C1410, C1957 AND C1958 B1 B2 Test Step CHECK FOR RETURNING DTCs Connect the scan tool. Using the scan tool, clear all ABS module DTCs. Test drive the vehicle above 32 km/h (20 mph) and carry out at least one ABS stop. Enter the following diagnostic mode on the scan tool: Self Test ABS Module. Do any ABS module DTCs return? CHECK THE VOLTAGE TO THE ABS MODULE Disconnect: ABS Module C135. Measure the voltage between ground and: ABS module C135-25, circuit SBB10 (YE/RD), harness side. ABS module C135-1, circuit SBB08 (VT/RD), harness side. ABS module C135-30, circuit CBP34 (VT/BN), harness side. Result / Action to Take REPAIR all other ABS module DTCs before repairing any valve coil failure DTCs. REFER to the ABS Module DTC Chart in this section. If multiple (2 or more) valve coil failure DTCs return, GO to B2. If only a single valve coil failure DTC returns, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. REPEAT the self-test with the brake pedal not applied. The system is operating correctly at this time. B3 Are the voltages greater than 10 volts? CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN GO to B3. If the voltage at pin 25 is less than 10 volts, VERIFY BJB fuse 10 (30A) is OK. If the voltage at pin 1 is less than 10 volts, VERIFY BJB fuse 8 (40A) is OK. If the voltage at pin 30 is less than 10 volts, VERIFY SJB fuse 34 (5A) is OK. If any fuse is not OK, REFER to Wiring Diagrams manual to identify the possible causes of the circuit short. If the fuses are OK, REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

13 Anti-Lock Brake System (ABS) and Stability Control PINPOINT TEST B: DTCs C1194, C1198, C1210, C1214, C1242, C1246, C1250, C1254, C1404, C1410, C1957 AND C1958 (Continued) B3 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN (Continued) Measure the resistance between ground and: ABS module C135-38, circuit GD120 (BK/GN), harness side. ABS module C135-13, circuit GD120 (BK/GN), harness side. B4 Are the resistances less than 5 ohms? CHECK FOR CORRECT ABS MODULE OPERATION Check ABS module C135 for: corrosion. pushed-out pins. spread terminals. Connect: ABS Module C135. Make sure the connector is fully seated and locked, then operate the system and verify the concern is still present. Is the concern still present? GO to B4. REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test. INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector or a malfunctioning charging system. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. Pinpoint Test C: DTCs C1095 and C1096 Refer to Wiring Diagrams Cell 42, Vehicle Dynamic Systems for schematic and connector information. rmal Operation Fused battery voltage for hydraulic pump motor operation is supplied to the ABS module by Battery Junction Box (BJB) fuse 8 (40A) along circuit SBB08 (VT/RD). Ground is provided to the ABS module along circuit GD120 (BK/GN). When the ignition key is turned to the ON position, the ABS module commands the Hydraulic Control Unit (HCU) pump on for 100 ms (±6 ms) and is then commanded off. After 6 ms, the ABS module will read the voltage that is being generated by the HCU pump. If the voltage indicates the motor is spinning at less than 500 rpm, there may be a locked motor. If this condition is detected 4 times, DTC C1095 is set. The pump motor is checked for an open circuit 2 seconds after the most recent successful pump motor off command. If the pump motor feedback remains greater than 0.75 volt for more than 50 ms (±6 ms) after these conditions have been met, DTC C1096 is set. DTC C1095 (ABS Hydraulic Pump Motor Circuit Failure) If a short to voltage or ground is detected, if a locked up pump motor is detected or if there is an internal failure of the ABS module, DTC C1095 will be set. DTC C1096 (ABS Hydraulic Pump Motor Circuit Open) If a short to voltage, a short to ground or an open is detected, if a locked up pump motor is detected or if there is an internal failure of the ABS module, DTC C1096 will be set. This pinpoint test is intended to diagnose the following: Fuse Wiring, terminals or connectors Hydraulic pump motor ABS module NOTICE: PINPOINT TEST C: DTCs C1095 AND C1096

14 Anti-Lock Brake System (ABS) and Stability Control PINPOINT TEST C: DTCs C1095 AND C1096 (Continued) Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes. C1 C2 C3 C4 Test Step CHECK THE ABS PUMP MOTOR Is the ABS pump motor running all the time? CHECK FOR ABS MODULE DTCs Connect the scan tool. Using the scan tool, clear the ABS module DTCs. Enter the following diagnostic mode on the scan tool: Self Test ABS Module. Retrieve and record all ABS module DTCs. Is DTC C1095 or C1096 present? CHECK FOR RETURNING ABS MODULE DTCs Using the scan tool, clear the ABS module DTCs. Test drive the vehicle at speeds greater than 32 km/h (20 mph) and carry out at least one ABS stop. Connect the scan tool. Enter the following diagnostic mode on the scan tool: Self Test ABS Module. Retrieve and record the ABS module DTCs. Are any DTCs present? CHECK THE VOLTAGE TO THE ABS MODULE Disconnect: ABS Module C135. Measure the voltage between ABS module C135-1, circuit SBB08 (VT/RD), harness side and ground. Result / Action to Take INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. REPEAT the self-test. GO to C2. If DTC C1095 is retrieved, GO to C4. If DTC C1096 is retrieved, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If DTC C1096 returns, INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. GO to C3. If DTC C1096 is retrieved, GO to C6. If DTC C1095 is retrieved, INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) in this section. CLEAR the DTCs. REPEAT the self-test. For all other ABS module DTCs, GO to the ABS Module DTC Chart. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. CARRY OUT the selftest with the brake pedal not applied. GO to C5. C5 Is the voltage greater than 10 volts? CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN Measure the resistance between ground and: VERIFY BJB fuse 8 (40A) is OK. If OK, REPAIR SBB08 (VT/RD). If not OK, REFER to the Wiring Diagrams manual to identify possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. GO to C6.

15 Anti-Lock Brake System (ABS) and Stability Control PINPOINT TEST C: DTCs C1095 AND C1096 (Continued) C5 CHECK THE ABS MODULE GROUND CIRCUITS FOR AN OPEN (Continued) ABS module C135-13, circuit GD120 (BK/GN), harness side. ABS module C135-38, circuit GD120 (BK/GN), harness side. C6 Are the resistances less than 5 ohms? CHECK FOR CORRECT ABS MODULE OPERATION Check ABS module C135 for: corrosion. pushed-out pins. spread terminals. Connect: ABS Module C135. Make sure the connector is fully seated and locked, then operate the system and verify the concern is still present. Is the concern still present? REPAIR circuit GD120 (BK/GN). CLEAR the DTCs. REPEAT the self-test. INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector or a malfunctioning charging system. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. Pinpoint Test D: DTCs C1145, C1155, C1165 and C1175 rmal Operation The wheel speed sensors are "active" sensors and generate a square wave signal that is sent to the ABS module. When the ignition is turned to the RUN position, the ABS module carries out a self-test to determine if the sensors are functional. Voltage and ground are supplied to the front wheel speed sensors from the ABS module along a pair of wires. Wheel speed sensor DTCs will automatically clear when a successful test drive is carried out. A successful test drive should include speeds above 32 km/h (20 mph) and at least one ABS stop. DTC Description C1145 RF Wheel Speed Sensor Input Circuit Failure C1155 LF Wheel Speed Sensor Input Circuit Failure C1165 RR Wheel Speed Sensor Input Circuit Failure C1175 LR Wheel Speed Sensor Input Circuit Failure Fault Trigger Condition If, during the ABS module on-demand self test or during normal operation, the ABS module detects an open, short to ground or voltage or a defective wheel speed sensor input circuit, the appropriate DTC will be set. These DTCs are usually set by a damaged sensor or a circuit fault. This pinpoint test is intended to diagnose the following: Wiring, terminals or connectors Wheel speed sensor ring Wheel speed sensor ABS module PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

16 Anti-Lock Brake System (ABS) and Stability Control D1 D2 D3 D4 D5 PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 (Continued) Test Step CHECK THE ABS HARNESS AND MODULE FOR WATER INTRUSION Disconnect: ABS Module C135. Inspect the ABS module connector and module for water intrusion. Is there any evidence of water entry? CHECK FOR FAULT REPEATABILITY Connect: ABS Module C135. Connect the scan tool. Using the scan tool, clear the ABS module DTCs. Drive the vehicle at least 16 km/h (10 mph). Enter the following diagnostic mode on the scan tool: Self Test ABS Module. Retrieve and document ABS module DTCs. Are DTCs C1145, C1155, C1165 and/or C1175 retrieved? Result / Action to Take CLEAN the connector and dry it out with low pressure compressed air. INSPECT for evidence of water entry and REPAIR as necessary. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. GO to D2. If the Rotunda Active Wheel Speed Sensor Tester is available, GO to D3. If the Rotunda Active Wheel Speed Sensor Tester is not available, GO to D5. INSPECT the wheel speed sensors, wheel speed sensor wiring and wheel speed sensor tone rings. REPAIR or INSTALL new as necessary. If any other DTCs are retrieved, GO to the ABS Module DTC Chart. CHECK THE ABS MODULE OUTPUT USING THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER Disconnect: Suspect Wheel Speed Sensor. Connect the Rotunda Active Wheel Speed Sensor Tester to the wheel speed sensor connectors. Select the correct system polarity on the Rotunda Active Wheel Speed Sensor Tester and turn the power switch to the ON position. Is the module output LED illuminated? GO to D4. GO to D7. CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER Raise the suspect wheel until it can spin freely. Refer to Section While monitoring the Rotunda Active Wheel Speed Sensor Tester, slowly spin the suspect wheel. Do the sensor output LEDs illuminate and flash and is the current overload LED not illuminated? CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO VOLTAGE NOTE: Both circuits must be checked for each DTC. Disconnect: ABS Module C135. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. If the current level LED is not illuminated and the sensor output LEDs do not illuminate or if the current level LED is illuminated red, INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor Front and/or Wheel Speed Sensor Rear in this section. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. CLEAR any DTCs. REPEAT the self-test. If the current level LED is not illuminated and the sensor output LEDs illuminate green but do not flash, INSPECT the wheel speed sensor tone ring and INSTALL new if necessary. If the tone ring is OK, INSTALL a new wheel speed sensor, REFER to Wheel Speed Sensor Front and/or Wheel Speed Sensor Rear in this section. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop. REPAIR the affected circuit(s). TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.

17 Anti-Lock Brake System (ABS) and Stability Control D5 PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 (Continued) CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO VOLTAGE (Continued) Disconnect: Suspect Wheel Speed Sensor. For DTC C1145 (RF), measure the voltage between ground and: ABS module C135-3, circuit VCA05 (GY/VT), harness side. ABS module C135-4, circuit RCA19 (VT), harness side. For DTC C1155 (LF), measure the voltage between ground and: ABS module C135-27, circuit VCA03 (VT/WH), harness side. ABS module C135-28, circuit RCA17 (YE), harness side. For DTC C1165 (RR), measure the voltage between ground and: ABS module C135-10, circuit RCA20 (BN), harness side. ABS module C135-11, circuit VCA06 (WH/OG), harness side. For DTC C1175 (LR), measure the voltage between ground and: ABS module C135-36, circuit VCA04 (BU/OG), harness side. ABS module C135-35, circuit RCA18 (BN/GN), harness side. GO to D6.

18 Anti-Lock Brake System (ABS) and Stability Control D5 PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 (Continued) CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO VOLTAGE (Continued) D6 Is any voltage present? CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND NOTE: Both circuits must be checked for each DTC. For DTC C1145 (RF), measure the resistance between ground and: ABS module C135-3, circuit VCA05 (GY/VT), harness side. ABS module C135-4, circuit RCA19 (VT), harness side. For DTC C1155 (LF), measure the resistance between ground and: ABS module C135-27, circuit VCA03 (VT/WH), harness side. ABS module C135-28, circuit RCA17 (YE), harness side. For DTC C1165 (RR), measure the resistance between ground and: ABS module C135-10, circuit RCA20 (BN), harness side. ABS module C135-11, circuit VCA06 (WH/OG), harness side. GO to D7. REPAIR the affected circuit(s). TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.

19 Anti-Lock Brake System (ABS) and Stability Control D6 PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND (Continued) For DTC C1175 (LR), measure the resistance between ground and: ABS module C135-36, circuit VCA04 (BU/OG), harness side. ABS module C135-35, circuit RCA18 (BN/GN), harness side. D7 Are the resistances greater than 10,000 ohms? CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN NOTE: Both circuits must be checked for each DTC. Disconnect: ABS Module C135. Measure the resistance between the ABS module connector, harness side and the suspect wheel speed sensor connector, harness side as indicated in the following chart: ABS Module Circuit Wheel Speed Sensor DTC C1145 (RF) Wheel Speed Sensor RF Input Circuit Failure C135-4 RCA19 (VT) C160-2 C135-3 VCA05 (GY/VT) C160-1 DTC C1155 (LF) Wheel Speed Sensor LF Input Circuit Failure C RCA17 (YE) C150-2 C VCA03 (VT/WH) C150-1 DTC C1165 (RR) Wheel Speed Sensor RR Input Circuit Failure C RCA20 (BN) C C VCA06 (WH/OG) C GO to D8. REPAIR the affected circuit(s). TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.

20 Anti-Lock Brake System (ABS) and Stability Control PINPOINT TEST D: DTCs C1145, C1155, C1165 AND C1175 D7 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN (Continued) (Continued) ABS Module Circuit Wheel Speed Sensor DTC C1175 (LR) Wheel Speed Sensor LR Input Circuit Failure C RCA18 (BN/GN) C C VCA04 (BU/OG) C Are the resistances less than 5 ohms? D8 CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS For DTC C1145 (RF), measure the resistance between RF wheel speed sensor C160-1, circuit VCA05 (GY/VT), harness side and RF wheel speed sensor C160-2, circuit RCA19 (VT), harness side. For DTC C1155 (LF), measure the resistance between LF wheel speed sensor C150-1, circuit VCA03 (VT/WH), harness side and LF wheel speed sensor C150-2, circuit RCA17 (YE), harness side. GO to D9. For DTC C1165 (RR), measure the resistance between RR wheel speed sensor C3117-1, circuit VCA06 (WH/OG), harness side and RR wheel speed sensor C3117-2, circuit RCA20 (BN), harness side. REPAIR the affected circuit(s). TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.