INSPECTION PROCEDURE 24: Backup lamp does not light up normally




COMMENTS ON TROUBLE SYMPTOM


When the back-up lamp does not illuminate or extinguish normally, the power supply or the earth circuit to the back-up lamp or the inhibitor switch may be defective.

PROBABLE CAUSES



  • Malfunction of the back-up lamp relay
  • Malfunction of the back-up lamp assembly
  • Malfunction of bulbs
  • Damaged harness or connector
  • Malfunction of PHEV-ECU

DIAGNOSIS PROCEDURE


STEP 1. Bulb check


Check the bulb(s) of the lamp that does not illuminate.

Q. Is the check result normal?

Go to Step 2.
Replace the bulb(s) of the lamp that does not illuminate.

STEP 2. Does the PHEV-ECU store a diagnosis code related to the back-up lamp?


Refer to .

Q. Is any diagnosis code stored?

Troubleshoot for the relevant diagnosis code.
Go to Step 3.

STEP 3. Check back-up lamp relay.


Refer to GROUP 54A- Back-up lamp relay check .

Q. Is the check result normal?

Go to Step 4.
Replace the back-up lamp relay.

STEP 4. Check of short to earth, and open circuit in the signal line (PHEV-ECU connector and ETACS-ECU connector).



  • Check the wiring harness between PHEV-ECU (BLP terminal) connector and the ETACS-ECU (IG11 terminal) connector.

Q. Is the check result normal?

Go to Step 5.
Repair the connector or wiring harness.

STEP 5. Check of short to earth, and open circuit in the signal line. (Back-up lamp relay connector and ETACS-ECU connector).



  • Check the wiring harness between ETACS-ECU (BLP+ terminal) connector and the back-up lamp relay connector terminal No.4.

  • Check the wiring harness between ETACS-ECU (BLP1 terminal) connector and the back-up lamp relay connector terminal No.3.

Q. Is the check result normal?

Go to Step 6.
Repair the connector or wiring harness.

STEP 6. Check of short to earth, and open circuit in the power supply line (ETACS-ECU connector and Back-up lamp <LH, RH> connector).



  • Check the wiring harness between ETACS-ECU (BLP2 terminal) connector and the back-up lamp <LH, RH> connector terminal No.2.

Q. Is the check result normal?

Go to Step 7.
Repair the connector or wiring harness.

STEP 7. Check of short to earth, and open circuit in the earth line (Back-up lamp <LH, RH> connector and body earth).



  • Check the wiring harness between back-up lamp <LH, RH> connector terminal No.1 and body earth.

Q. Is the check result normal?

Go to Step 8.
Repair the connector or wiring harness.

STEP 8. M.U.T.-III other system diagnosis code



  • Use M.U.T.-III to check whether the ETACS-ECU related diagnosis code is stored or not. (Refer to GROUP 54A - ETACS, Diagnosis Code Chart ).

Q. Is the diagnosis code stored?

Troubleshoot for the relevant diagnosis code.
Go to Step 9.

STEP 9. M.U.T.-III actuator test (PHEV-ECU).


Actuator test
  • Execute the following actuator tests:
Item 2. Back lamp relay actuate
OK: When the actuator test is started, the DC-DC converter drive stops.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Go to Step 10.

STEP 10. Retest the system.


Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Replace the PHEV-ECU (Refer to ).