CRUISE CONTROL WITH ELECTRIC ACTUATOR Group 61 - Chassis Electrics Produced By: BMW of North America, Inc Issued 7/83 61-09
CRUISE CONTROL WITH ELECTRIC ACTUATOR The electric actuator type cruise control system was introduced on the BMW 733i and 528e models in 1982. From 1983 all six-cylinder models will use this type. The system is designed to operate at between 20 and approximately 90 mph. An electronic control unit (E.C.U.) controls an electric actuator which maintains the desired road speed via the throttle linkage. Driver control is through a three-function switch operated by a lever mounted on the right side of the steering column behind the wiper lever. Pushing the lever forward in the CONST position engages the system and the car will accelerate until the lever is released. The E.C.U. contains a memory circuit which will hold the speed that exists when the lever is released from the CONST. position. Momentary operation of the lever in the CONST. position will also cause engagement and lock the prevailing speed into the memory. Cruise control may be disengaged in any of five different ways; momentarily moving the control switch up or down to OFF, applying the foot brake, shifting the automatic transmission to neutral, depressing the clutch, or whenever the actual speed drops more than 15 mph below the memory speed. Following disengagement, the car can be returned to the previously selected speed by pulling the control lever to RESUME. The memory circuits in the E.C.U. are reset whenever the lever is moved to CONST, but the only time the memory is cleared is when ignition is turned off. The E.C.U. receives a processed signal from the electronic speedometer, which is equivalent to actual road speed. Consequently, speedometer problems will affect cruise control.
ACTUATOR CABLE GAS LINKAGE CLUTCH SWITCH BRAKE SWITCH P R N D 2 1 BRIDGE (AUTOMATIC) ECU SPEEDO OFF REED SWITCH CONST. RESUME CRUISE CONTROL SCHEMATIC (ELECTRIC ACTUATOR) OFF 61-09/1
CRUISE CONTROL SYSTEM TESTS (ELECTRIC ACTUATOR) Use BMW Service Test 2013 to check function of system as follows: Program: Enter M (Multimeter) Enter 13 (Frequency out) Enter 110 (Hz) Press Enter 02 (U. AC.) Press 1. Detach the differential reed switch plug and attach frequency out (+) to brown/red wire and frequency out (-) to brown wire. 2. Turn on ignition. 3. Speedometer should show approximately 50 mph. 4. Engage cruise control and monitor the actuator. (It should pull the throttle open.) 5. If cruise control does not engage, check for A.C. voltage on E.C.U. plug terminal #6. (It should be approximately 4.0 volts.) 6. Check plug connections on back of instrument cluster. 7. If system is still inactive, perform the following tests: Test at ECU Plug Component/Circuit Result 1. Ignition on check voltage at Terminal #1. Power supply 12 Volts. If not, check wiring and fuse. 2. Ignition on check voltage at Terminal #2. Control switch OFF Move lever to OFF. Voltage drops from 12V to 0V. If not, check wiring and switch. 3. Ignition on check voltage at Terminal #4. Control switch CONST. Move lever to CONST. Voltage jumps 0 to 12V. If not, check wiring and switch. 61-09/2
Test at ECU Plug Component/Circuit Result 4. Ignition on check voltage at Terminal #5. Control switch RESUME. Move lever to RESUME. Voltage jumps 0 to 12V. If not, check wiring and switch. 5. Measure resistance Terminal #3 to ground. (Auto transmission in neutral.) (Ignition off.) A.) Automatic Transmission B.) Manual Transmission A.) Approximately 4 B.) < 1 6. Apply voltage to term. #8 and ground term. #9. Actuator solenoid (Clutch) Listen for click in actuator 7. Measure resistance Terminal #8 to ground. Actuator and clutch switch. Resistance approx. 30 Press clutch pedal, then resistance = oo If not, check wiring, clutch switch, and brake lights. 8. Apply voltage to term. #13 and ground term. #25. Actuator motor Listen for motor running. 9. Measure resistance Terminal #24 to Terminal #23. Actuator potentiometer. Resistance approx. 3000 If not, check wiring/ replace actuator. 10. Measure resistance Terminal #23 to ground. Ground Resistance = 0 If not, check wiring and ground. 11. Measure resistance Terminal #26 to ground. Actuator. Resistance approx. 3000 If not, check wiring/ replace actuator. 12. Measure voltage at term. #9 (Ignition on) Brake light switch 0 Volts then depress brake pedal voltage = 12V. 61-09/3
C250.5 VI/WT 1.5 VI/WT FUSE 12 8 AMP.5 VI/WT POWER DISTRIBUTION BOX POWER DISTRIBUTION POWER DISTRIBUTION FUSE 6 BOX 8 AMP.75 GN/WT POWER DISTRIBUTION 1 1.5 GN/WT 1 GN/WT 11 1 GN/WT.75 GN/WT S217 C206 S309 C301 AUTOMATIC TRANSMISSION STOP LIGHTS BRAKE SWITCH CLOSED WITH BRAKE PEDAL DEPRESSED.5 GN/RD MANUAL AUTOMATIC TRANSMISSION C208 TRANSMISSION CLUTCH SWITCH.5 GN/RD OPENS WHEN CLUTCH PEDAL IS DEPRESSED C208 S241 SPEEDOMETER.5 VI/WT SOLID STATE 2 C8 CRUISE CONTROL 1 CONTROL UNIT.5 BU/YL POWER INPUT VEHICLE SPEED FOR CRUISE CONTROL TO BE ENGAGED INPUT PIN 9 MUST SENSE GROUND THROUGH STOPLIGHTS. WHEN BRAKE SWITCH IS CLOSED OR CLUTCH SWITCH IS OPEN, GROUND IS ELECTRONICALLY REMOVED. CRUISE MANUAL ENABLE TRANSMISSION 9.75 INSTRUMENT BU/BR CLUSTER SPEEDOMETER C8 INSTRUMENT CLUSTER GROUND FEEDBACK REFERENCE.5 VI/WT C210 GN/WT 24 26.5 GY/RD.5 GN/YL 4.5 RD SOLID STATE FEEDBACK INPUT 7.5 YL OFF 0 OFF RESUME GN W C210 CANCEL RESUME ACCELERATE/ SPEED SET SPEED CONTROL INPUTS ACCELERATE/ SET CRUISE CONTROL SWITCH CRUISE CONTROL CONTROL UNIT CLUTCH CONTROL CONTROL MOTOR CRUISE OUTPUT OUTPUT ENABLE.5 WT.5 GN BU.5 YL.5 GN.5 BU 5 4 13.5 BK 5.5 BK S.5 BU/WT 2.5 BU C209 3.75 BU/BR 7.75 GN/WT AUTOMATIC TRANSMISSION RANGE SWITCH 3 15 1 P 2 R D N 6.75 8U/3R.75 BU/BR IDLE SPEED S234 CONTROL.75 BU/BR TRANSMISSION RANGE 6 DISPLAY "N".5 GN/RD (-) 12 C6.5 BR CRUISE CONTROL GROUND.5 GN/RD 16 C1.5 BR.5 BR FEEDBACK POTENTIOMETER OUTPUT BAND CLUTCH SOLENOID CONTROL MOTOR ACTUATOR SEE DASH LIGHTS S233 3.5 BR.5 WT G200.5 BR G200 TO THROTTLE VALVE G200.5 GN/RD S224 CRUISE CONTROL ELECTRICAL SCHEMATIC 61-09/5
CRUISE CONTROL WITH VACUUM SERVO Group 61 - Chassis Electrics Produced by BMW OF NORTH AMERICA, INC. Revised 7/83 61-08
CRUISE CONTROL The BMW cruise control is designed to operate between 20 and approximately 90 mph. An electronic control unit (E.C.U.) controls a vacuum operated servo unit which actuates the throttle linkage to maintain the required road speed. Drive control is through a three function switch operated by a lever mounted on the right side of the steering column behind the wiper lever. Pushing the lever forward in the CONST position engages the system and the car will accelerate until the lever is released. The E.C.U. contains a memory circuit which will hold the speed that exists when the lever is released from the CONST position. Momentary operation of the lever in the CONST position will also cause engagement and lock the prevailing speed into the memory. Cruise control may be disengaged in any of five different ways: momentarily moving the control switch up or down to OFF, applying the foot brake, shifting the transmission to neutral, or whenever the actual speed drops more than 7 mph below the memory speed. Following disengagement, the car can be returned to the previously selected speed by pulling the control lever to RESUME. The memory circuits in the E.C.U. are reset whenever the lever is moved to CONST but the only time the memory is cleared is when ignition is turned off.
SERVO CABLE GAS LINKAGE VACUUM VENT BRAKE SWITCH P R N D 2 1 ADAPTER ECU SPEEDO CABLE OFF CONST. SIGNAL GENERATOR RESUME SPEEDO OFF REED SWITCH CRUISE CONTROL SCHEMATIC 61-08/1
CRUISE CONTROL SYSTEM TESTS - 733i (VACUUM SERVO) A. Vacuum - Check fit and condition of all vacuum and vent lines. B. Electrical TEST AT ECU PLUG COMPONENT/CIRCUIT RESULT 1. Measure resistance across term. 1-12 push car min. 2 feet 2. Ignition on. Check voltage at term. 5. 3. Start car. Jumper term. 5-3 and then 12-7 momentarily. 4a. Ignition on (not running). Check voltage at term. 6. b. Ignition off. Check resistance terminal 6 to ground. 5. Ignition on. Check voltage at term. 8. 6. Ignition on. Check voltage at term. 9. 7. Ignition on. Check voltage at term. 10. Reed switch in differential and wiring. Power supply. Servo System disconnect circuit. Adaptor ground. Control switch OFF. Control switch CONST. Control switch RESUME Resistance changes 0 to oo to 0, etc. If not, check wiring and switch. Voltage - 12V. If not, check wiring. Servo should activate and raise engine speed. If not, check wiring and Servo. No voltage. Push brake pedal then voltage = 12V, or trans. to 'N' and voltage = 12V. If not, check wiring, switches, and adaptor. Reading approx. 20 to 150 Now reverse leads and reading must remain between 20 and 1 5 0. If reading is at oo with either hook up check adaptor grounding or replace adaptor. Move lever to OFF. Voltage drops from 12 -> 0 volts. If not, check wiring and switch. Move lever to CONST. Voltage jumps 0 to 12 volts. If not, check wiring and switch. Move lever to RESUME. Voltage jumps 0 to 12 volts. If not, check wiring and switch. If these electrical tests are OK, then change the control unit if the system does not operate correctly. 61-03/2
GN-green WS-white BL-blue GE-yellow BR-brown RT-red VI-violet 1. Control Unit (ECU) 5. Adaptor 9. Fuses 2. Reed Switch 6. Trans. Lights (Instruments) 10. Relief Relay 3. Servo 7. Brake Switch 11. Ignition Switch 4. Control Switch 8. Brake Light 12. Battery CRUISE CONTROL ELECTRICAL SCHEMATIC 733IA 61-08/3
CRUISE CONTROL SYSTEM TESTS - 633CSi (VACUUM SERVO) A, Vacuum - Check fit and condition of all vacuum and vent lines. B. Electrical TEST AT ECU PLUG COMPONENT/CIRCUIT RESULT 1. Measure A/C voltage across terms. 11-12. Car on hoist in gear and running. 2. Ignition on. Check voltage at term. 5. 3. Start car. Jumper term. 5-3 and then 12-7 momentarily. 4a. Ignition on (not running). Check voltage at term. 6. b. Ignition off. Check resistance terminal 6 to ground. 5. Ignition on. Check voltage at term. 8. 6. Ignition on. Check voltage at term. 9. 7. Ignition on. Check voltage at term. 10. Signal Generator and wiring. Power supply. Servo. System disconnect circuit. Adaptor ground. Control switch OFF. Control switch CONST. Control switch RESUME. 10 mph approx. 0.7 V A/C 20 mph approx. 1.4 V A/C 30 mph approx. 2.1 V A/C 40 mph approx. 2.8V A/C Voltage - 12V. If not, check wiring. Servo should activate and raise engine speed. If not, check wiring and Servo. No voltage. Push brake pedal then voltage = 12V, or trans. to 'N' and voltage = 12V. If not, check wiring, switches, and adaptor. Reading approx 20 to 150. Now reverse leads and reading must remain between 20 and 150 If reading is at oo with either hook up check adaptor grounding or replace adaptor. Move lever to OFF. Voltage drops from 12 -> 0 volts. If not, check wiring and switch. Move lever to CONST. Voltage jumps 0 to 12 volts. If not, check wiring and switch. Move lever to RESUME. Voltage jumps 0 to 12 volts. If not, check wiring and switch. If these electrical tests are OK, then change the control unit if the system does not operate correctly. 61-08/4
GN-green BR-brown WS-white RT-red BL-blue VI-violet GE-yellow 1. Control Unit (ECU) 5. Control Switch 9. Fuses 2. Signal Generator 6. Battery 10. Relief Relay 3. Ignition Switch 7. Adaptor 11. Brake Light 4. Servo 8. Trans. Lights 12. Brake Switch CRUISE CONTROL ELECTRICAL SCHEMATIC 633CSiA 61-08/5
THROTTLE LINKAGE NIPPLE l-2mm VACUUM VENT ELECTRIC SOLENOID CRUISE CONTROL VACUUM SERVO