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DTC C1000: Abnormality in stoplight switch circuit <Vehicles without 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 there is difference between the stoplight state and the vehicle's behavior
 
 
 
PROBABLE CAUSES
  • Malfunction of the stoplight
  • Improper adjustment of stoplight switch installation position
  • Damaged wiring harness and connectors
  • ETACS-ECU malfunction
  • ASC-ECU malfunction
 
 
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use M.U.T.-III to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). On completion, go to Step 2.
 
STEP 2. DTC recheck after resetting CAN bus lines
Is DTC No.C1000 set?
Go to Step 3.
This procedure is complete.
 
STEP 3. Scan tool other system's data list
Check the ETACS-ECU system data list.
  • The brake pedal is depressed.
 
Item No.Item nameNormal condition
290Stoplight switchOFF to ON
Is the check result normal?
Go to Step 4.
Refer to GROUP 54A - ETACS, Inspection Procedure 13 "ETACS-ECU does not receive any signal from the stoplight switch <Vehicles without stop light relay> ."
 
STEP 4. DTC recheck
Erase the DTC.
Is DTC No.C1000 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
 
STEP 5. DTC recheck
Erase the DTC.
Is DTC No.C1000 set?
Return to Step 1.
This procedure is complete.