C1000

DTC C1000: Abnormality in stoplight switch circuit













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 CAN Bus Line Diagnostics Flow ).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
- When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to Testing and Inspection , Testing and Inspection and Testing and Inspection ).

OPERATION

ETACS-ECU sends the ON signal generated when the brake pedal is depressed and OFF signal generated when it is released to ASC-ECU via the CAN bus lines.

DTC SET CONDITIONS

This diagnostic trouble code is set in the following case.

- When the vehicle has run for a long time with the stoplight switch turned ON.
- When there is difference between the stoplight state and the vehicle's behavior

PROBABLE CAUSES

- Malfunction of the stoplight relay
- Malfunction of the stoplight
- Damaged wiring harness and connectors
- ETACS-ECU malfunction
- ASC-ECU malfunction

DIAGNOSIS

STEP 1. Check that the stoplight of the rear combination light illuminates normally.

Q. Is the check result normal?

YES Go to Step 2.
NO Diagnose the rear combination light Symptom Chart). On completion, go to Step 2 .
STEP 2. Using scan tool MB991958, diagnose the CAN bus lines.

Use scan tool MB991958 to diagnose the CAN bus lines.

Q. Is the check result normal?

YES Go to Step 4.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart).
On completion, go to Step 3.
STEP 3. DTC recheck after resetting CAN bus lines

Q. Is DTC C1000 set?

YES Go to Step 4.
NO The procedure is complete.
STEP 4. Battery check

Battery Test.

Q. Is the battery in good condition?

YES Go to Step 5.
NO Charge or replace the battery, and go to Step 10.
STEP 5. Connector check: C-410 ETACS-ECU connector

Q. Is the check result normal?

YES Go to Step 6.
NO Repair the damaged connector.
STEP 6. Measure the voltage at the C-410 ETACS-ECU connector.

(1)Measure by backprobing without disconnecting the ETACS-ECU connector and stoplight switch connector.

(2)Disconnecting the C-29 stoplight relay connector.

(3)Measure the voltage between the C-410 ETACS-ECU connector terminal No.16 and the body ground.
OK:

When the brake pedal is released: Approximately 0 V - 5 V (pulse)
When the brake pedal is depressed: Approximately system voltage


Q. Is the check result normal?

YES Go to Step 9.
NO Go to Step 7.
STEP 7. Connector check: C-410 ETACS-ECU connector

Q. Is the check result normal?

YES Go to Step 8.
NO Repair the damaged connector.
STEP 8. Check the wiring harness between C-410 ETACS-ECU connector terminal No.16 and C-29 stoplight relay connector terminal No.7

- Check the signal line for open circuit.

Q. Is the check result normal?

YES Go to Step 9.
NO Replace the wiring harness.
STEP 9. Diagnostic trouble code recheck

Erase the DTC.

Q. Is diagnostic trouble code No.C1000 set?

YES Replace the hydraulic unit (integrated with ASC-ECU) (Refer to Service and Repair).
Then go to Step 10.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).
STEP 10. Diagnostic trouble code recheck

Erase the DTC.

Q. Is diagnostic trouble code No.C1000 set?

YES Return to Step 1.
NO The procedure is complete.