INSPECTION PROCEDURE P-3: The back-up lamp switch signal is not received. <M/T>


caution Whenever the ECU is replaced, ensure that the input signal circuit is normal.


COMMENTS ON TROUBLE SYMPTOM
Input signal from the back-up lamp switch is used to operate the rear wiper. If the signal is abnormal, the rear wiper will not work normally.

POSSIBLE CAUSES

  • Malfunction of the back-up lamp switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Connector check: B-110 back-up lamp switch connector and C-220 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 2.

Repair the defective connector.

Step 2. Check the back-up lamp switch
Check the back-up lamp switch (Refer to GROUP 22B - Transmission ).

Q. Is the check result normal?
Go to Step 3.
Replace the inhibitor switch.

Step 3. Voltage measurement C-220 ETACS-ECU connector.

(1)Disconnect the connector, and measure at the wiring harness side.
(2)Ignition switch: ON
(3)Shift position: R position

(4)Voltage between C-220 ETACS-ECU connector terminal No.39 and body earth
OK: System voltage

Q. Is the check result normal?

Replace the ETACS-ECU.

Go to Step 4.

Step 4. Voltage measurement at the B-110 back-up lamp switch connector.

(1)Disconnect the connector, and measure at the wiring harness side.
(2)Ignition switch: ON

(3)Voltage between B-110 back-up lamp switch connector terminal No.2 and body earth
OK: System voltage

Q. Is the check result normal?

Go to Step 5.

Go to Step 6.

Step 5. Check the wiring harness between B-110 back-up lamp switch connector terminal No.1 and C-220 ETACS-ECU connector terminal No.39.



note Prior to the wiring harness inspection, check intermediate connector C-18, and repair if necessary.

  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

Step 6. Check the wiring harness between B-110 back-up lamp switch connector terminal No.2 and the ignition switch (IG1).



note Prior to the wiring harness inspection, check joint connector C-116, intermediate connector C-18, junction block connectors C-202 and C-203, and repair if necessary.

  • Check the power supply line to the ignition switch (IG1) for open circuit.

Q. Is the check result normal?

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

Repair the wiring harness.

Step 7. Retest the system.
Check that the back-up lamp switch signal is received normally.

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 ETACS-ECU.