Inspection Procedure G-1

Rear Wiper and Washer: Rear Wiper does no not Work at All

Rear Wiper Drive Circuit:

Connector:

NOTE: This troubleshooting requires use of scan tool MB991502 and SWS monitor kit MB991862. For details of how to use the SWS monitor, refer to "How to use SWS monitor".

CIRCUIT OPERATION
- The rear wiper switch sends a signal through the column-ECU (incorporated in the column switch) to the ETACS-ECU. If the column-ECU sends a rear wiper switch "ON" signal to the ETACS-ECU, the ETACS-ECU turns on the relay (incorporated in the ETACS-ECU), thus causing the rear wiper motor to be turned on.
- The ETACS-ECU operates the rear wiper according to the following switches:
- Ignition switch (ACC)
- Rear wiper switch

TECHNICAL DESCRIPTION (COMMENT)
If the rear wiper does not work normally, the input circuit system from the switches, the rear wiper motor, the column switch (windshield wiper and windshield washer switch) or the ETACS-ECU may be defective (refer to "CIRCUIT OPERATION"),

TROUBLESHOOTING HINTS
- Malfunction of the rear wiper motor
- Malfunction of the column switch (windshield wiper and washer switch)
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS monitor kit







STEP 1. Use scan tool to select "ECU CHECK" on the SWS monitor display.
Check the following ECUs:
- ETACS-ECU
- column-ECU

CAUTION: To prevent damage to scan toot MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan toot MB991502. Also connect SWS monitor kit MB991862 after turning on scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Connect SWS monitor kit MB991862 to the column switch connector.
3. When the ignition switch is turned to the "ON" position, scan tool MB991502 should show "OK" on the "ECU CHECK" menu.

Q: Are "OK" displayed on the "ETACS ECU" and "COLUMN ECU"?
"OK" are displayed for all the items : Go to STEP 2.
"NG" is displayed on the "ETACS ECU" menu : Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is impossible."
"NG" is displayed on the "COLUMN ECU" menu : Refer to Inspection Procedure A-2 "Communication with column switch (column-ECU) is impossible."

STEP 2. Check the input signal by using service data of the SWS monitor.







Check the input signals from the following switches:
- ignition switch: ACC
- rear wiper switch: INT




Select "REAR WIPER - REAR WIPER" (FUNCTION DIAG.), and check that normal conditions are displayed on the items described in the table above.

Q: Are normal conditions displayed on the "REAR WIPER SW" and "IG SW (ACC)"?

YES: Go to STEP 3.

NO:
- Normal condition is not displayed on the "REAR WIPER SW': Refer to Inspection Procedure L-6 "ETACS-ECU does not receive a signal from the rear wiper switch."
- Normal condition is not displayed on the "IG SW (ACC)": Refer to Inspection Procedure L-1 "ETACS-ECU does not receive a signal from the ignition switch (ACC)."




STEP 3. Check the rear wiper motor.
1. Disconnect rear wiper motor connector F-05.
2. Connect the battery to the rear wiper motor, and check the rear wiper motor.

Q: Does the rear wiper motor operate normally?

YES: Go to Step 4.

NO: Replace the rear wiper motor. Check that the rear wiper works normally




STEP 4. Check at rear wiper motor connector F-05 to check the rear wiper motor ground circuit.
1. Disconnect rear wiper motor connector F-05, and measure at the wiring harness side.
2. Measure the resistance value between terminal 1 and ground.
- The measured value should be 2 Ohm or less.

Q: Does the measured resistance value correspond with this range?

YES: Go to Step 7.

NO: Go to Step 5.




STEP 5. Check rear wiper motor connector F-05 for damage.

Q: Is rear wiper motor connector F-05 in good condition?

YES: Go to Step 6.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the rear wiper works normally.




STEP 6. Check the wiring harness between rear wiper motor connector F-05 and ground.

Q: Is the wiring harness between rear wiper motor connector F-05 and ground in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the rear wiper works normally.







STEP 7. Check rear wiper motor connector F-05 and ETACS-ECU connector C-226 for damage.

Q: Are rear wiper motor connector F-05 and ETACS-ECU connector C-226 in good condition?

YES: Go to Step 8.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the rear wiper works normally.










STEP 8. Check the wiring harness between rear wiper motor connector F-05 and ETACS-ECU connector C-226.

NOTE: Also check junction block connector C-217. If junction block connector C-217 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between rear wiper motor connector F-05 and ETACS-ECU connector C-226 in good condition?

YES: Replace the ETACS-ECU. Check that the rear wiper works normally.

NO: Repair the wiring harness. Check that the rear wiper works normally.