Inspection Procedure L-3
ETACS-ECU does not Receive "R" Position Signal from the Backup Light SwitchBackup Light Switch Input Circuit:
Connectors:
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
- 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)
STEP 1. Check the backup light switch.
Disconnect backup light switch connector B-111. Then check continuity between the switch terminals.
Q: Is the backup light switch in good condition?
YES: Go to Step 2.
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 2. Check at backup light switch connector B-111 in order to check the ignition switch (IG1) line of the power supply to the backup light switch.
1. Disconnect backup light switch connector B-111, and measure at the wiring harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 1 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).
Q: Does the measured voltage correspond with this range?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check backup light switch connector B-111 for damage.
Q: Is the backup light switch connector B-111 in good condition?
YES: Go to Step 4.
NO: Repair or replace the connector. Refer to 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 4. Check the wiring harness between backup light switch connector B-111 and the ignition switch (IG1).
NOTE: Also check junction block connectors C-210, C-211 and intermediate connector C-123. If junction block connectors C-210, C-211 or intermediate connectors C-123 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between backup light switch connector B-111 and the ignition switch (IG1) in good condition?
YES: No action to be taken.
NO: Repair the wiring harness. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.
STEP 5. Check backup light switch connector B-111 and ETACS-ECU connector C-227 for damage. Q:Are backup light switch connector B-111 and ETACS-ECU connector C-227 in good condition?
YES: Go to Step 6.
NO: Repair or replace the connector. Refer to 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-111 and ETACS-ECU connector C-227.
NOTE: Also check joint connector C-101 and intermediate connector C-124. If joint connector C-101 or intermediate connectors C-124 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between backup light switch connector B-111 and ETACS-ECU connector C-227 in good condition?
YES: Replace the ETACS-ECU. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.
NO: Repair the wiring harness. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the backup light switch.
ETACS-ECU does not Receive "R" Position Signal from the Park/neutral Position Switch
Park/Neutral Position Switch Input Circuit:
Connectors:
CIRCUIT OPERATION
The ETACS-ECU operates the rear wiper according to signal from the park/neutral position switch.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the rear wiper does not operate consecutively twice when the selector lever is moved to the "R" position with the rear wiper on. If the signal is not normal, the park/neutral position switch or the ETACS-ECU may be defective.
NOTE: The park/neutral position switch is shared with the automatic transmission control system. If this problem is not solved, carry out the troubleshooting regarding the automatic transmission control system. Refer to A/T Diagnosis.
TROUBLESHOOTING HINTS
- Malfunction of the park/neutral position switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
STEP 1. Check the park/neutral position switch.
Disconnect park/neutral position switch connector B-16. Then check continuity between the switch terminals.
Q: Is the park/neutral position switch in good condition?
YES: Go to Step 2.
NO: Replace the park/neutral position switch. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.
STEP 2. Check at park/neutral switch connector B-16 in order to check the ignition switch (IG1) line of the power supply to the park/neutral switch.
1. Disconnect park/neutral position switch connector B-16, and measure at the wiring harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 8 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).
Q: Does the measured voltage correspond with this range?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check park/neutral position switch connector B-16 for damage.
Q: Is park/neutral position switch connector B-16 in good condition?
YES: Go to Step 4.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.
STEP 4. Check the wiring harness between park/neutral position switch connector B-16 and the ignition switch (IG1).
NOTE: Also check junction block connectors C-210, C-211 and intermediate connector C-123. If junction block connectors C-210, C-211 or intermediate connectors C-123 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between park/neutral position switch connector B-16 and the ignition switch (IG1) in good condition?
YES: No action to be taken.
NO: Repair the wiring harness. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.
STEP 5. Check park/neutral position switch connector B-16 and ETACS-ECU connector C-227 for damage.
Q:Are park/neutral position switch connector B-16 and ETACS-ECU connector C-227 in good condition?
YES: Go to Step 6.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.
STEP 6. Check the wiring harness between park/neutral position switch connector B-16 and ETACS-ECU connector C-227.
NOTE: Also check joint connector C-101 and intermediate connector C-124. If joint connector C-101 or intermediate connectors C-124 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between park/neutral position switch connector B-16 and ETACS-ECU connector C-227 in good condition?
YES: Replace the ETACS-ECU. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.
NO: Repair the wiring harness. If the rear wiper operates normally, it indicates that a correct "R" position signal is sent from the park/neutral position switch.