Active Center Differential (ACD)
DTC C1000: Stoplight Switch System
CAUTION:
- If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
AWC-ECU receives signals of stoplight switch from ETACS-ECU via the CAN bus lines.
DTC SET CONDITIONS
This diagnostic trouble code is set when the abnormality below is detected:
- The vehicle has run for a long time with the stop light switch turned ON.
- With the stoplight switch OFF, the vehicle speed is decelerated suddenly.
PROBABLE CAUSES
- Incorrect adjustment of stoplight switch position
- Malfunction of stoplight switch
- Stoplight malfunction
- Damaged harness wires and connectors
- Malfunction of the ETACS-ECU
- Malfunction of AWC-ECU
DIAGNOSTIC PROCEDURE
STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q. Is the check result normal?
YES Go to Step 3.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart). After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.
Q. Is DTC No. C1000 set?
YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. Check of the stoplight on and off.
Check that the stoplight illuminates when the brake pedal is depressed, and the stoplight goes out when the brake pedal is released.
Q. Is the check result normal?
YES Go to Step 14.
NO Go to Step 4.
STEP 4. Stoplight switch installation status check.
Service and Repair.
Q. Is the check result normal?
YES Go to Step 5.
NO Install the stoplight switch correctly. Then go to Step 18.
STEP 5. Check the stoplight switch.
Testing and Inspection.
Q. Is the check result normal?
YES Go to Step 6.
NO Replace the stoplight switch. Service and Repair). Then go to Step 18.
STEP 6. ETACS-ECU connector check: C-304
Q. Is the check result normal?
YES Go to Step 7.
NO Repair the defective connector. Then go to Step 18.
STEP 7. Measure the voltage at the C-304 ETACS-ECU connector.
Disconnect the connector, and measure the voltage between terminal No.1 and ground at the ECU side.
OK: Battery positive voltage
Q. Is the check result normal?
YES Go to Step 8.
NO Replace the ETACS-ECU. Electronic Time and Alarm Control System (ETACS)-ECU Removal and Installation. Then go to Step 18.
STEP 8. Stoplight switch connector check: C-32
Q. Is the check result normal?
YES Go to Step 9.
NO Repair the defective connector. Then go to Step 18.
STEP 9. Voltage measurement at the C-32 stoplight switch connector.
Disconnect the connector, and measure the voltage between terminal No.2 and ground at the wiring harness side.
OK: Battery positive voltage
Q. Is the check result normal?
YES Go to Step 11.
NO Go to Step 10.
STEP 10. Check the wiring harness between C-304 ETACS-ECU connector terminal No.1 and C-32 stoplight switch connector terminal No.2.
Check the output line for open or short circuit.
Q. Is the check result normal?
YES Go to Step 11.
NO Repair the wiring harness. Then go to Step 18.
STEP 11. Intermediate connector, stoplight switch connector, ETACS-ECU connector check: C-39, C-32, C-312
Q. Is the check result normal?
YES Go to Step 12.
NO Repair the defective connector. Then go to Step 18.
STEP 12. Voltage measurement at C-39 intermediate connector.
Disconnect the connector, and measure the voltage between terminal No.9 and ground at the wiring harness side.
OK: Battery positive voltage (brake pedal depressed)
Q. Is the check result normal?
YES Go to Step 14.
NO Go to Step 13.
STEP 13. Check the wiring harness between C-32 stoplight switch connector terminal No.1 and the C-39 intermediate connector terminal No.9.
Check the output line for open or short circuit.
Q. Is the check result normal?
YES Go to Step 16.
NO Repair the wiring harness. Then go to Step 18.
STEP 14. Measure the voltage at the C-312 ETACS-ECU connector.
Disconnect the connector, and measure the voltage between terminal No.16 and ground at the wiring harness side.
- OK: 1 V or less (brake pedal released)
- OK: Battery positive voltage (brake pedal depressed)
Q. Is the check result normal?
YES Go to Step 16.
NO Go to Step 15.
STEP 15. Check the wiring harness between C-312 ETACS-ECU connector terminal No.16 and C-38 stoplight switch connector terminal No.1.
Check the output line for open circuit.
Q. Is the check result normal?
YES Go to Step 16.
NO Repair the wiring harness. Then go to Step 18.
STEP 16. Scan tool data list
Item No.39: Stoplight switch (Refer to data list reference table Data List Reference Table.)
Q. Is the check result normal?
YES Go to Step 17.
NO Replace the ETACS-ECU. Electronic Time and Alarm Control System (ETACS)-ECU Removal and Installation). Then go to Step 18.
STEP 17. Check whether the DTC is reset.
Q. Is DTC No. C1000 set?
YES Replace the AWC-ECU. (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST)). Then go to Step 18.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions).
STEP 18. Check whether the DTC is reset.
Q. Is DTC No. C1000 set?
YES Return to Step 1.
NO This diagnosis is complete.