Inspection Procedure 3: Back-Up Light Does Not Illuminate

INSPECTION PROCEDURE 3: Back-up light does not illuminate.




















CAUTION
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

COMMENTS ON TROUBLE SYMPTOM
The back-up light, ETACS-ECU, or shift lever-ECU may have a problem.

PROBABLE CAUSES
^ Malfunction of the ETACS-ECU
^ Malfunction of the back-up light
^ Damaged harness wires and connectors
^ Malfunction of the shift lever-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.

Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines. After repairing the CAN bus line, go to Step 2.

STEP 2. Scan tool actuator test
Item No.2: Back-up light (Refer to Special Function (Actuator Test Reference Table.)

Q: Is the check result normal?
YES: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction.)
NO: Go to Step 3.

STEP 3. Scan tool diagnostic trouble code
Check the ETACS diagnostic trouble code.

Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 4.

STEP 4. Bulb check
Check if the bulb of the back-up light which does not illuminate is normal.

Q: Is the check result normal?
YES: Go to Step 5.
NO: Replace the bulb.

STEP 5. Measure the resistance at F-08 back-up light (RH) connector and F-17 back-up light (LH) connector.
Disconnect the connector, and measure the resistance between the connector terminal No.2 and ground at the wiring harness side.
OK: Continuity exists. (2 Ohms or less)

Q: Is the check result normal?
YES: Go to Step 8.
NO: Go to Step 6.

STEP 6. Inspection of the back-up light (RH) connector, back-up light (LH) connector, and intermediate connector: F-08, F-17, F-23
Check for the contact with the connector terminals.

Q: Is the check result normal?
YES: Go to Step 7.
NO: Repair the defective connector.

STEP 7. Check the wiring harness between F-08 back-up light (RH) connector terminal No. 2 and body ground, and between F17 back-up light (LH) connector terminal No.2 and body ground.
Check the ground line for open circuit.

Q: Is the check result normal?
YES: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction.)
NO: Repair the wiring harness.

STEP 8. Measure the voltage at F-08 back-up light (RH) connector and F-17 back-up light (LH) connector.
1) Disconnect the connector, and measure the voltage between the connector terminal No.3 and ground at the wiring harness side.
2) Turn the ignition switch to the "ON" position.
3) Place the shift lever to the R range.
OK: Battery positive voltage

Q: Is the check result normal?
YES: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction.)
NO: Go to Step 9.

STEP 9. Inspection of J/C (4), intermediate connector, shift lever assembly connector, ETACS-ECU connector, and back-up light connector: C-38, C-39, C-49, C-304, C-311, C-313, D-14, F-08, F-17, F-23
Check for the contact with the connector terminals.

Q: Is the check result normal?
YES: Go to Step 10.
NO: Repair the defective connector.

STEP 10. Check the wiring harness between F-08 back-up light (RH) connector terminal No.3 and C-311 ETACS-ECU connector terminal No.2, and between F-17 back-up light (RH) connector terminal No.3 and C-311 ETACS-ECU connector terminal No.2.
Check the power supply line for open or short circuit.

Q: Is the check result normal?
YES: Go to Step 11.
NO: Repair the wiring harness.

STEP 11. Check the wiring harness between C-49 shift lever assembly connector terminal No.3 and C-304 ETACS-ECU connector terminal No.2.
Check the power supply line for open or short circuit.

Q: Is the check result normal?
YES: Go to Step 12.
NO: Repair the wiring harness.

STEP 12. Check the wiring harness between C-49 shift lever assembly connector terminal No.4 and C-313 ETACS-ECU connector terminal No.4.
Check the power supply line for open or short circuit.

Q: Is the check result normal?
YES: Replace the ETACS-ECU. Then go to Step 13.
NO: Repair the wiring harness.

STEP 13. Retest the system.

Q: Does a malfunction take place again?
YES: Replace the shift lever assembly.
NO: This diagnosis is complete.