2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 347 P2120 Throttle / Pedal Position Sensor / Switch "D" Circuit P2122 Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input P2123 Throttle / Pedal Position Sensor / Switch "D" Circuit High Input P2125 P2127 Throttle / Pedal Position Sensor / Switch "E" Circuit Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input P2128 Throttle / Pedal Position Sensor / Switch "E" Circuit High Input P2138 Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation These s relate to the Accelerator Pedal Position (APP) sensor. DCRIPTION This accelerator pedal position sensor is a non - contact type. This ETCS (Electronic Throttle Control System) does not use a throttle cable. The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA1 (main) and (sub). The voltage, which is applied to terminals VPA1 and of the ECM, varies between 0 V and 5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA1 indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from conveys the status of the VPA1 circuit and is used to check the APP sensor itself. The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA1 and, and controls the throttle actuator according to these signals.
348 2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM Accelerator Pedal Position Sensor Accelerator Pedal Position Sensor Output Voltage (V) IC No.1 Magnet VPA EPA VCPA EPA2 ECM 5 3.7 to 4.4 2.9 to 3.6 1.6 1.4 *1 *2 IC No.2 0 Usable Range 25 Magnet Accelerator Pedal Turning Angle(deg) *1 : Accelerator Pedal Fully Released *2 : Accelerator Pedal Fully Depressed A115889E01 No. Detection Condition Trouble Area P2120 P2122 P2123 P2125 P2127 P2128 P2138 Condition continues for 0.5 second or more: VPA is 0.4 V or less when accelerator pedal is fully released, or VPA is 4.8 V or more Condition continues for 0.5 second or more when accelerator pedal is fully released: VPA is 0.2 V or less Condition continues for 2.0 seconds or more: VPA is 4.8 V or more Condition continues for 0.5 second or more: ( is 0.5 V or less when accelerator pedal is fully released) or ( is 4.8 V or more and VPA is between 0.4 V and 3.45 V) 1.2 V or less for 0.5 seconds or more when accelerator pedal fully released Conditions and (b) continue for 2.0 seconds or more 4.8 V or more (b) VPA between 0.4 V and 3.45 V Condition or (b) continues for 2.0 seconds or more Difference between VPA and 0.02 V or less (b) VPA1 0.4 V or less and 1.2 V or less Accelerator Pedal Position (APP) sensor Open in VCPA circuit Open or short in VPA circuit Open in EPA circuit Open in circuit Open or short in circuit Open in EPA2 circuit Short between VPA and circuits
2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 349 After confirming P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use the intelligent tester or the OBD II scan tool to confirm the throttle valve opening percentage. Accelerator pedal position expressed as voltage Trouble Area Accelerator pedal released Accelerator pedal depressed ACCEL POS #1 ACCEL POS #2 ACCEL POS #1 ACCEL POS #2 VC circuit open 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V 0 to 0.2 V VPA circuit open or short 0 to 0.2 V 1.2 to 2.0 V 0 to 0.2 V 3.4 to 5.3 V circuit open or short 0.5 to 1.1 V 0 to 0.2 V 2.6 to 4.5 V 0 to 0.2 V E2 circuit open 4.5 to 5.5 V 4.5 to 5.5 V 4.5 to 5.5 V 4.5 to 5.5 V Accelerator pedal positions are expressed as voltages. AP stands for Accelerator Pedal. MONITOR DCRIPTION When VPA or deviates from the standard, or the difference between the voltage outputs of the two sensors is less than threshold, the ECM concludes that there is a defect in the accelerator pedal position sensor. The ECM turns on the MIL and a is set. Example: When the voltage output of the VPA is below 0.2 V or exceeds 4.8 V. MONITOR STRATEGY P2120: Accelerator Pedal Position (APP) sensor 1 range check (fluctuating) P2122: APP sensor 1 range check (low voltage) P2123: APP sensor 1 range check (high voltage) Related s P2125: APP sensor 2 range check (fluctuating) P2127: APP sensor 2 range check (low voltage) P2128: APP sensor 2 range check (high voltage) P2138: APP sensor range check (correlation) Required Sensors/Components (Main) APP sensor Required Sensors/Components (Related) - Frequency of Operation Continuous Duration 2.0 seconds MIL Operation Immediate Sequence of Operation None TYPICAL ENABLING CONDITIONS Monitor runs whenever following s not present Ignition switch Throttle actuator power None ON ON TYPICAL MALFUNCTION THRHOLDS P2120: Either of the following conditions is met: Condition 1 or 2 1. VPA1 voltage when voltage is 0.04 V or more 0.4 V or less 2. VPA1 voltage 4.8 V or more P2122: VPA1 voltage when voltage is 0.04 V or more 0.4 V or less
350 P2123: VPA1 voltage 2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 4.8 V or more P2125: Either of the following conditions is met: Condition 1 or 2 1. voltage when VPA1 is 0.04 V or more 1.2 V or less 2. voltage when VPA1 is 0.4 to 3.45 V 4.8 V or more P2127: voltage when VPA1 0.04 V or more P2128: voltage when VPA1 0.4 to 3.45 V 1.2 V or less 4.8 V or more P2138: Either of following conditions is met: Condition 1 or 2 Condition 1 - Difference between VPA1 and voltages 0.02 V or less Condition 2 Condition and (b) VPA1 voltage 0.4 V or less (b) voltage 1.2 V or less COMPONENT OPERATING RANGE VPA1 voltage voltage Difference between VPA1 and voltages 0.4 to 4.8 V 1.2 to 4.8 V More than 0.02 V FAIL-SAFE The accelerator pedal position sensor has two (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and switches to limp mode. In limp mode, the remaining circuit is used to calculate the accelerator pedal opening to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed. In this case, the throttle valve will remain closed as if the engine is idling. If a "pass" condition is detected and then the ignition switch is turned OFF, the fail-safe operation will stop and the system will return to normal condition.
2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 351 WIRING DIAGRAM A24 Accelerator Pedal Position Sensor ECM VPA1 6 W-R 18 VPA EP1 VCP1 5 4 LG-B B-Y 20 26 EPA VCPA EP2 3 2 1 R-B V-W W-L 19 21 27 EPA2 A115926E02 INSPECTION PROCEDURE Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction. 1 READ VALUE OF INTELLIGENT TTER (ACCEL POS #1 AND ACCEL POS #2) (b) (c) (d) Connect the intelligent tester to the DLC3 with CAN VIM. Turn the ignition switch ON and turn the tester ON. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ETCS / ACCEL POS #1 and ACCEL POS #2. Read the values displayed on the tester. Standard voltage Depressed Released FI07052E06 Accelerator Pedal ACCEL POS #1 ACCEL POS #2 Released 0.5 to 1.1 V 1.5 to 2.9 V Depressed 2.5 to 4.6 V 3.5 to 5.5 V OK Go to step 5 NG
352 2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 2 CHECK HARNS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM) Wire Harness Side A24 Front View Accelerator Pedal Position Sensor Connector EP2 ECM Connector EP1 VCP1 VPA1 (b) (c) Disconnect the A24 accelerator pedal position sensor connector. Disconnect the ECM connector. Measure the resistance between the wire harness side connectors. Standard resistance (Check for open) Tester Connection VPA1 (A24-6) - VPA (-18) EP1 (A24-5) - EPA (-20) VCP1 (A24-4) - VCPA (-26) (A24-3) - (-19) EP2 (A24-2) - EPA2 (-21) (A24-1) - (-27) Specified Condition Below 1 Ω Standard resistance (Check for short) EPA2 EPA VPA VCPA A115719E02 Tester Connection VPA1 (A24-6) or VPA (-18) - Body EP1 (A24-5) or EPA (-20) - Body VCP1 (A24-4) or VCPA (-26) - Body (A24-3) or (-19) - Body Specified Condition 10 kω or higher EP2 (A24-2) or EPA2 (-21) - Body (A24-1) or (-27) - Body (d) (e) Reconnect the ECM connector. Reconnect the accelerator pedal position sensor connector. NG REPAIR OR REPLACE HARNS OR CONNECTOR OK
2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM 353 3 INSPECT ECM (VCPA AND VOLTAGE) Accelerator Pedal Position Sensor Connector A24 (b) (c) (d) Disconnect the A24 APP sensor connector. Turn the ignition switch ON. Measure the voltage of the ECM connector. Standard voltage Tester Connection VCPA (-26) - EPA (-20) (-27) - EPA2 (-21) Reconnect the APP sensor connector. Specified Condition 4.5 to 5.0 V VPA NG REPLACE ECM EPA2 ECM Connector EPA VCPA A138089E01 OK 4 REPLACE ACCELERATOR PEDAL ROD ASSEMBLY Replace accelerator pedal rod assembly (See page - 483). NEXT 5 CHECK WHETHER OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR S) (b) (c) (d) (e) (f) Connect the intelligent tester to the DLC3 with CAN VIM. Turn the ignition switch ON and turn the tester ON. Clear s (See page -35). Allow the engine to idle for 15 seconds. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / INFO / CURRENT COD. Read s. Result Display ( Output) Proceed to P2120, P2122, P2123, P2125, P2127, P2128 or P2138 A No output B B SYSTEM OK
354 2UZ-FE ENGINE CONTROL SYSTEM SFI SYSTEM A REPLACE ECM