Inspection Procedure O-6

Backup Light Switch Input Circuit:

Connectors:

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

TECHNICAL DESCRIPTION (COMMENT)
The backup light switch input signal is used to operate the rear wiper. If the signal is an error, the rear wiper will not operate consecutively twice when the rear wiper is on and the shift lever is moved to "R" position.

TROUBLESHOOTING HINTS
- Malfunction of the backup light switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tools:
MB991223: Test Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness







STEP 1. Check the backup light switch.
If the backup light switch is damaged, repair it.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.
If the backup light switch is in good condition, go to Step 2.




STEP 2. Check the backup light switch power supply circuit at the backup light switch connector B-37.
1. Disconnect the backup light switch connector B-37 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Voltage between terminal 1 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
If not approximately 12 volts, go to Step 3.
If approximately 12 volts, go to Step 5.




STEP 3. Check the backup light switch connector B-37 for damage.
If the backup light switch connector B-37 is damaged, repair or replace it. Refer to Harness Connector Inspection.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.
If the connector is in good condition, go to Step 4.










STEP 4. Check the harness wires between backup light switch connector B-37 and ignition switch (IG1).

NOTE: After checking intermediate connector C-28 and junction block connectors C-101 and C-107, check the wires. If intermediate connector C-28 and junction block connectors C-101 and C-107 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If the harness wires between backup light switch connector B-37 and ignition switch (IG1) are damaged, repair them.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.







STEP 5. Check the backup light switch connector B-37 and ETACS-ECU connector C-111 for damage.
If the backup light switch connector B-37 and ETACS-ECU connector C-111 are damaged, repair or replace them. Refer to Harness Connector Inspection.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.
If the connectors are in good condition, go to Step 6.










STEP 6. Check the harness wires between backup light switch connector B-37 and ETACS-ECU connector C-111.

NOTE: After checking intermediate connector C-28, check the wires. If intermediate connector C-28 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between backup light switch connector B-37 and ETACS-ECU connector C-111 are damaged, repair them.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.
If the harness wires are in good condition, replace the ETACS-ECU.
The backup light switch input signal should be able to be checked and the rear wiper should work normally.