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DTC C1000 Abnormality in stoplight switch circuit <Vehicles with stoplight relay>
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Line Diagnostic 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 , and ).
 
 
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 DTC is set in the following case.
  • When the vehicle has run for a long time with the stoplight switch turned ON.
  • When the OFF status of the stoplight switch does not match the vehicle attitude
 
 
 
PROBABLE CAUSES
  • Damaged wiring harness and connectors
  • Improper adjustment of stoplight switch installation position
  • Malfunction of the stoplight switch
  • Malfunction of the stoplight relay
  • Malfunction of ETACS-ECU
  • ASC-ECU malfunction
 
 
 
 
DIAGNOSIS
STEP 1. Check that the stoplight of the rear combination lamp illuminates normally.
Is the check result normal?
Go to Step 2
Perform the troubleshooting for the rear combination lamp (Refer to GROUP 54A - Rear Combination Lamp/Trouble Symptom Chart ). On completion, go to Step 2.
 
STEP 2. Using scan tool (M.U.T.-III) CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 4
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table). On completion, go to Step 3.
 
STEP 3. DTC recheck after resetting CAN bus lines
Is DTC C1000 set?
Go to Step 4
This diagnosis is complete.
 
STEP 4. Battery check
Refer to GROUP 54A - Battery Test .
Is the battery in good condition?
Go to Step 5
Charge or replace the battery, and go to Step 10.
 
STEP 5. Connector check: C-410 ETACS-ECU connector
Is the check result normal?
Go to Step 6
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
Is the check result normal?
Go to Step 9
Go to Step 7
 
STEP 7. Connector check: C-410 ETACS-ECU connector
Is the check result normal?
Go to Step 8
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.3
  • Check the signal line for open circuit.
Is the check result normal?
Go to Step 9
Replace the wiring harness.
 
STEP 9. DTC recheck
Erase the DTC.
Is DTC C1000 set?
Replace the hydraulic unit (integrated with ASC-ECU). Then go to Step 10.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions).
 
STEP 10. DTC recheck
Erase the DTC.
Is DTC C1000 set?
Return to Step 1.
Turn the ignition switch from OFF to ON and depress the brake pedal several times. If the DTC is not set again, this diagnosis is complete.