C1340
DTC C1340: Stoplight switch
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.
CIRCUIT OPERATION
- The "ON" signal when the brake pedal is pressed or the "OFF" signal when the brake pedal is released is input to the TCL/ASC-ECU (terminal 41).
DTC SET CONDITIONS
Diagnosis code No.1340 is set in the following cases:
- Stoplight switch is not operating properly and remains ON state and vehicle speed exceeds 12mph (20km/h) for more than 6 minutes.
- Stoplight switch system harness is damaged and no signal is input to TCL/ASC-ECU.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THESE DTCS ARE TO SET ARE:)
Current trouble
- Malfunction of the stoplight switch
- Incorrect positioning of stoplight switch
- Damaged wiring harness or connector
- Malfunction of the hydraulic unit (integrated with TCL/ASC-ECU)
PAST TROUBLE
Carry out diagnosis with particular emphasis on connector(s) or wiring harness between the TCL/ASC-ECU and the stoplight switch. For diagnosis procedures, refer to "How to cope with past trouble" How to Treat Past Trouble).
DIAGNOSIS
Required Special Tools:
- MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827 M.U.T.-III USB Cable
- MB991910 M.U.T.-III Main Harness A
- MB991997: ASC Check Harness
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the CAN bus line found to be normal?
YES Go to Step 3.
NO Repair the CAN bus line CAN Bus Diagnostics Chart). Then go to Step 2.
STEP 2. Recheck for diagnostic trouble code.
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the DTC.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the DTC is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is DTC C1340 set?
YES Go to Step 3.
NO The procedure is complete.
STEP 3. Check the stoplight operation.
(1)Turn the ignition switch to the "ON" position.
(2)Check the operation of the stoplight when the brake pedal is operated.
OK:
Brake pedal depressed: ON
Brake pedal released: OFF
Q. Is the check result normal?
YES Go to Step 4.
NO Go to Step 6.
STEP 4. Connector check: A-38 TCL/ASC-ECU connector, C-28 joint connector (1).
Q. Is the check result normal?
YES Go to Step 5.
NO Repair or replace the damaged component(s). Then go to Step 16.
STEP 5. Measure the resistance at the C-28 joint connector (1).
(1)Disconnect the connector C-28 joint connector (1) and A-38 TCL/ASC-ECU connector, and measure the wiring harness-side connector.
(2)Measure the resistance between the C-28 joint connector (1) terminal 15 and A-38 TCL/ASC-ECU connector terminal 41.
OK: Continuity exists (2 ohms or less)
Q. Is the check result normal?
YES Go to Step 15.
NO Repair the harness wire. Then go to Step 16.
STEP 6. Connector check: A-38 TCL/ASC-ECU connector, C-28 joint connector (1), C-103 stoplight switch connector, C-26 intermediate connector, F-02 intermediate connector (ECLIPSE), F-05 (standard type rear spoiler) or F-30 (large type rear spoiler) high-mounted stoplight, F-07 rear combination light (RH), F-14 rear combination light (LH)
Q. Is the check result normal?
YES Go to Step 7.
NO Repair or replace the damaged component(s). Then go to Step 16.
STEP 7. Check for stoplight switch installation
Testing and Inspection.
Q. Is the check result normal?
YES Go to Step 8.
NO Install the stoplight switch correctly Testing and Inspection). Then go to Step 16.
STEP 8. Check for stoplight switch
Testing and Inspection.
Q. Is the check result normal?
YES Go to Step 9.
NO Replace the stoplight switch Service and Repair). Then go to Step 16.
STEP 9. Check the fuse No. 11.
Visually check for melted fuse.
Q. Is the check result normal?
YES Go to Step 13.
NO Go to Step 10.
STEP 10. Measure the resistance at the C-103 stoplight switch connector.
(1)Disconnect the connector C-103, and measure at the wiring harness-side connector.
(2)Remove fuse No. 11.
(3)Measure the resistance between the C-103 stoplight switch connector terminal 2 and body ground.
OK: No continuity
Q. Is the check result normal?
YES Go to Step 11.
NO The wiring harness between fuse No. 11 and C-103 stoplight switch connector terminal 2 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11.Then go to Step 16 .
STEP 11. Measure the resistance at the C-103 stoplight switch connector.
(1)Disconnect the connector C-103, and measure at the wiring harness-side connector.
(2)Disconnect the connector C-28 joint connector (1).
(3)Measure the resistance between the C-103 stoplight switch connector terminal 1 and body ground.
OK: No continuity
Q. Is the check result normal?
YES Go to Step 12.
NO The wiring harness between C-28 joint connector (1) terminal 12 and C-103 stoplight switch connector terminal 1 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11.Then go to Step 16.
STEP 12. Measure the resistance at the C-28 joint connector (1).
(1)Disconnect the connector C-28, and measure at the wiring harness-side connector.
(2)Disconnect the connector A-38 TCL/ASC-ECU connector.
(3)Measure the resistance between the C-28 joint connector (1) terminal 15 and body ground.
OK: No continuity
Q. Is the check result normal?
YES The wiring harness between C-28 joint connector (1) terminal 17 and F-05 (standard type rear spoiler) or F-30 (large type rear spoiler) high-mounted stoplight connector terminal 2 or the wiring harness F-07 rear combination light (RH) connector terminal 2 and F-11 rear combination light (LH) connector terminal 2 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11.Then go to Step 15.
NO The wiring harness between C-28 joint connector (1) terminal 15 and A-38 TCL/ASC-ECU connector terminal 41 is shorted to ground. Repair the wiring harness. Then, replace fuse No. 11.Then go to Step 16.
STEP 13. Measure the resistance at the C-103 stoplight switch connector.
(1)Disconnect the connector C-103, and measure at the wiring harness-side connector.
(2)Remove fuse No. 11.
(3)Measure the resistance between the C-103 stoplight switch connector terminal 2 and Fuse No.11.
OK: Continuity exists (2 ohms or less)
Q. Is the check result normal?
YES Go to Step 14.
NO An open circuit is present in the wiring harness between fuse No. 11 and C-103 stoplight switch connector terminal 2. Repair the wiring harness.Then go to Step 16.
STEP 14. Measure the resistance at the C-103 stoplight switch connector.
(1)Disconnect the connector C-103, and measure at the wiring harness-side connector.
(2)Disconnect the connector C-28 joint connector (1).
(3)Measure the resistance between the C-103 stoplight switch connector terminal 1 and C-28 joint connector (1) terminal 12.
OK: Continuity exists (2 ohms or less)
Q. Is the check result normal?
YES Go to Step 15.
NO An open circuit is present in the wiring harness between C-28 joint connector (1) terminal 12 and C-103 stoplight switch connector terminal 1. Repair the wiring harness.Then go to Step 16.
STEP 15. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the DTC.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the DTC is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is DTC C1340 set?
YES Replace the hydraulic unit (integrated with TCL/ASC-ECU). Then go to Step 16.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 16. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the DTC.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Drive the vehicle at 12 mph (20km/h) or more for 6 minutes or more. (there is no need to drive continuously).
(6)Stop the vehicle with braking at 25 mph (40km/h) or more.
(7)Check if the DTC is set.
(8)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is DTC C1340 set?
YES Go to Step 1.
NO The procedure is complete.