Inspection Procedure M-4

INSPECTION PROCEDURE M-4: ETACS-ECU does not receive "R" position signal from the backup light switch [M/T].


























CIRCUIT OPERATION

The ETACS-ECU operates the rear wiper according to signal from the backup light switch.

TECHNICAL DESCRIPTION (COMMENT)

If the signal is not normal, the rear wiper does not operate consecutively twice when the shift lever is moved to the "R" position with the rear wiper on. If the signal is not normal, the backup light switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS

- The backup light switch may be defective
- The ETACS-ECU may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check backup light switch connector B-114 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is the backup light switch connector B-114 in good condition?

YES Go to Step 2.

NO Repair or replace the damaged component(s). Harness Connector Inspection. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.

STEP 2. Check the backup light switch.





Disconnect backup light switch connector B-114. Then check continuity between the switch terminals.





Q. Is the backup light switch in good condition?

YES Go to Step 3.

NO Replace the backup light switch. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.

STEP 3. Check the ignition switch (IG1) circuit to the backup light switch. Measure the voltage at backup light switch connector B-114.





(1)Disconnect backup light switch connector B-114 and measure the voltage available at the wiring harness side of the connector.
(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal 2 and ground.

- The voltage should equal approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts (battery positive voltage)?

YES Go to Step 5.

NO Go to Step 4.

STEP 4. Check the wiring harness between backup light switch connector B-114 (terminal 2) and the ignition switch (IG1).

- Check the power supply line for open circuit and short circuit.

















NOTE:
Also check junction block connectors C-202, C-203, joint connector C-28, intermediate connectors A-15 and C-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connectors C-202, C-203, joint connector C-28, intermediate connectors A-15 or C-24 are damaged, Repair or replace the damaged component(s) as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between backup light switch connector B-114 (terminal 2) and the ignition switch (IG1) in good condition?

YES Inspection Procedure.

NO The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.

STEP 5. Check ETACS-ECU connector C-219 for damage.





Q. Is ETACS-ECU connector C-219 in good condition?

YES Go to Step 6.

NO Repair or replace the connector. Harness Connector Inspection. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.

STEP 6. Check the wiring harness between backup light switch connector B-114 (terminal 1) and ETACS-ECU connector C-219 (terminal 39).

- Check the communication lines for open circuit and short circuit.

















NOTE:
Also check intermediate connectors A-15, C-23 and C-26. If intermediate connectors A-15, C-23 or C-26 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between backup light switch connector B-114 (terminal 1) and ETACS-ECU connector C-219 (terminal 39) in good condition?

YES Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.

NO The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.