Inspection Procedure 3: The back-up lamps do not illuminate normally.

caution

Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM

If both of the back-up lamps do not illuminate normally, the back-up lamp relay or the EV-ECU may be defective.

PROBABLE CAUSES

Malfunction of the back-up lamp relay
Malfunction of the EV-ECU
Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III other system actuator test

Check if the diagnosis code is set to the EV-ECU.

Q. Is the diagnosis code set?

	Diagnose the EV-ECU.(GROUP 54D - Electric motor control unit .)

	Go to Step 2.

STEP 2. Connector check: B-311 back-up lamp relay connector

Q. Is the check result normal?

	Go to Step 3.

	Repair the defective connector.

STEP 3. Check the back-up lamp relay

Refer to

Q. Is the check result normal?

	Go to Step 4.

	Replace the back-up lamp relay.

STEP 4. Measure voltage at B-311 back-up lamp relay connector

(1)Remove the back-up lamp relay, and measure at the junction block side.

(2)Move the electric motor switch to the ON position.

(3)Measure the voltage between the back-up lamp relay connector terminal Nos. 1, 4 and body earth.
OK: System voltage

Q. Is the check result normal?

	Go to Step 6.

	Go to Step 5.

STEP 5. Check the wires between the B-311 back-up lamp relay connector terminal No.1, 4 and the electric motor switch (ON)

note

Before the wiring harness check, check the B-302 junction block connector, and repair if necessary.

Check the power supply line for open circuit.

Q. Is the check result normal?

	Go to Step 6.

	Repair the wiring harness.

STEP 6. Connector check: C-108 EV-ECU connector

Q. Is the check result normal?

	Go to Step 7.

	Repair the defective connector.

STEP 7. Check the wires between the B-311 back-up lamp relay connector terminal No. 2 and the C-108 EV-ECU connector terminal No. 57.

note

Before the wiring harness check, check the B-303 junction block connector, and repair if necessary.

Check the output lines for open circuit.

Q. Is the check result normal?

	Go to Step 8.

	Repair the wiring harness.

STEP 8. Check the wires between the B-311 back-up lamp relay connector terminal No. 3 and the C-07 intermediate connector terminal No. 9.

note

Before the wiring harness check, check the B-319 junction block connector, and repair if necessary.

Check the output lines for open circuit and short circuit.

Q. Is the check result normal?

	Go to Step 9.

	Repair the wiring harness.

STEP 9. Retest the system

Check that the back-up lamps illuminate normally.

Q. Is the check result normal?

	The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

	Replace the EV-ECU.

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