Code No. C1000 Abnormality in stop lamp switch circuit




















caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C, CAN Bus Diagnosis Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.

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.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set in the following case.

  • When the vehicle has run for a long time with the stop lamp switch turned ON.
  • When the OFF status of the stop lamp switch does not match the vehicle attitude

PROBABLE CAUSES

  • Improper adjustment of stop lamp switch installation position
  • Stop lamp switch malfunction
  • Damaged wiring harness and connectors
  • Malfunction of ETACS-ECU
  • ASC-ECU malfunction

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus lines. (Refer to GROUP 54C - CAN Bus Diagnosis table .) On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines

Q. Is diagnosis code No.C1000 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Battery check
Refer to GROUP 54A - Battery Test .

Q. Is the battery in good condition?
Go to Step 4.
Charge or replace the battery, and go to Step 17.

STEP 4. Stop lamp operation check
Check the stop lamp operation when the brake pedal is depressed. Check that all the stop lamp illuminates when the brake pedal is depressed and that it goes out when the brake pedal is released.
OK:
    When the brake pedal is released: OFF
    When the brake pedal is depressed: Illuminates

Q. Is the check result normal?
Go to Step 18.
Go to Step 5.

STEP 5. Check for stop lamp switch installation
Refer to GROUP 35A - On-vehicle Service .

Q. Is the check result normal?
Go to Step 6.
Install the stop lamp switch correctly. (Refer to GROUP 35A - On-vehicle Service .) Then go to Step 21.

STEP 6. Stop lamp switch continuity check
(1)Remove the stop lamp switch. (Refer to GROUP 35A - Brake Pedal .)

(2)Connect the circuit tester (Ω range) to the stop lamp switch connector terminals No. 1 and 2.
(3)When no continuity is detected with the plunger pressed from the edge of the outer case by the dimension shown in the figure and when continuity is detected with the plunger released, the stop lamp switch is in good condition.

Q. Is the check result normal?

Go to Step 7.

Replace the stop lamp switch. (Refer to GROUP 35A - Brake Pedal .) Then go to Step 21.

STEP 7. ETACS-ECU fuse No.2 check

Q. Is the check result normal?
Go to Step 12.
Go to Step 8.

STEP 8. Connector check: C-304 ETACS-ECU connector, C-312 ETACS-ECU connector, C-24 stop lamp switch connector, C-31 Intermediate connector, C-30 joint connector, D-12 Intermediate connector, D-16 Intermediate connector, F-39 Intermediate connector, F-08 rear combination lamp (stop: RH) connector, F-23 rear combination lamp (stop: LH) connector, F-11 highmounted stop lamp connector

Q. Is the check result normal?
Go to Step 9.
Repair the damaged connector, and then replace fuse No.2. Then go to Step 21.

STEP 9. Resistance measurement at C-24 stop lamp switch connector
(1)Disconnect C-24 stop lamp switch connector, and measure at the wiring harness side.
(2)Disconnect C-312 ETACS-ECU connector and C-30 joint connector.
(3)Measure the resistance between the terminal No.1 and the body earth.
OK: No continuity

Q. Is the check result normal?
Go to Step 10.
An short circuit may be present in the wiring harness between C-30 joint connector terminal No.2 and C-24 stop lamp switch connector terminal No.1 or between C-312 ETACS-ECU connector terminal No.16 and C-24 stop lamp switch connector terminal No.1. Repair the wiring harness, and then replace fuse No.2. Then go to Step 21.

STEP 10. Resistance measurement at C-24 stop lamp switch connector
(1)Disconnect C-24 stop lamp switch connector, and measure at the wiring harness side.
(2)Disconnect C-304 ETACS-ECU connector.
(3)Measure the resistance between the terminal No.2 and the body earth.
OK: No continuity

Q. Is the check result normal?
Go to Step 11.
An short circuit may be present in the wiring harness between C-304 ETACS-ECU connector terminal No.1 and C-24 stop lamp switch connector terminal No.2. Repair the wiring harness, and then replace fuse No.2. Then go to Step 21.

STEP 11. Resistance measurement at C-30 joint connector
(1)Disconnect C-30 joint connector, and measure at the wiring harness side.
(2)Disconnect F-08 rear combination lamp (stop: RH) connector, F-23 rear combination lamp (stop: LH) connector, F-11 highmounted stop lamp connector.
(3)Measure the resistance between the terminal No.2 and the body earth.
OK: No continuity

Q. Is the check result normal?
Replace fuse No.2. Then go to Step 21.
An short circuit may be present in the wiring harness between C-30 joint connector terminal No.2 and F-08 rear combination lamp (stop: RH) connector terminal No.1 or between C-30 joint connector terminal No.2 and F-23 rear combination lamp (stop: LH) connector terminal No.1 or between C-30 joint connector terminal No.2 and F-11 highmounted stop lamp connector terminal No.2. Repair the wiring harness, and then replace fuse No.2. Then go to Step 21.

STEP 12. Connector check: C-304 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 13.
Repair the damaged connector.

STEP 13. Measure the voltage at the C-304 ETACS-ECU connector.
caution Measure while the brake pedal is not depressed.
Measure the voltage between terminal No. 1 and the body earth by backprobing.
OK: Approximately battery voltage

Q. Is the check result normal?
Go to Step 14.
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU ). Then go to Step 21.

STEP 14. Connector check: C-24 Stop lamp switch connector

Q. Is the check result normal?
Go to Step 15.
Repair the damaged connector.

STEP 15. Measure the voltage at C-24 stop lamp switch connector.
(1)Disconnect C-24 stop lamp switch connector, and measure the voltage at harness connector side.
(2)Measure the voltage between the terminal No.2 and the body earth.
OK: Approximately battery voltage

Q. Is the check result normal?
Go to Step 16.
An open circuit may be present in the wiring harness between C-304 ETACS-ECU connector terminal No. 1 and C-24 stop lamp switch connector terminal No. 2. Repair the wiring harness.

STEP 16. Connector check: C-30 joint connector

Q. Is the check result normal?
Go to Step 17.
Repair the damaged connector.

STEP 17. Voltage measurement at C-30 joint connector
caution Measure while the brake pedal is depressed.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the terminal No.2 and the body earth.
OK: Approximately battery voltage

Q. Is the check result normal?
Go to Step 18.
An open circuit may be present in the wiring harness between C-30 joint connector terminal No.2 and C-24 stop lamp switch connector terminal No.1. Repair the wiring harness.

STEP 18. Connector check: C-312 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 19.
Repair the damaged connector.

STEP 19. Measure the voltage at the C-312 ETACS-ECU connector.
(1)Measure by backprobing without disconnecting the connector.
(2)Measure the voltage between the terminal No.16 and the body earth.
OK:
    When the brake pedal is released: Approximately 0 V
    When the brake pedal is depressed: Approximately battery voltage

Q. Is the check result normal?
Go to Step 20.
An open circuit may be present in the wiring harness between C-312 ETACS-ECU connector terminal No.16 and C-24 stop lamp switch connector terminal No.1. Repair the wiring harness.

STEP 20. Diagnosis code recheck

Q. Is diagnosis code No.C1000 set?
Replace the hydraulic unit (ASC-ECU) (Refer to ). Then go to Step 21.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 21. Diagnosis code recheck

Q. Is diagnosis code No.C1000 set?
Return to Step 1.
This diagnosis is complete.