Inspection Procedure 3

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

DIAGNOSIS

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. CAN Bus Diagnostics Chart.) 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 Actuator Test Reference Table.))

Q. Is the check result normal?

YES Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
NO Go to Step 3.
STEP 3. Scan tool diagnostic trouble code

Check the ETACS diagnostic trouble code. Electronic Time and Alarm Control System (ETACS).)

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-22 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. (2ohms 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-22, F-27

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 F-22 back-up light (LH) connector terminal No.1 and body ground.

Check the ground line for open circuit.

Q. Is the check result normal?

YES Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
NO Repair the wiring harness.
STEP 8. Measure the voltage at F-08 back-up light (RH) connector and F-22 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. How to Cope With Intermittent Malfunctions.)
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-43, C-47, C-27, C-304, C-311, C-313, D-17, F-08, F-22, F-27

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-22 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-27 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-27 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. Electronic Time and Alarm Control System (ETACS)-ECU Removal and Installation. 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. (Refer to Service and Repair.)
NO This diagnosis is complete.