Inspection Procedure F-2

Windshield Wiper and Washer: The Windshield Wipers do not Work When the Windshield Wiper Switch is at "INT" or "MIST" Position or the Windshield Washer Switch is at "ON" Position. However, the Wipers Work at Low Speed when the Windshield Wiper Switch is at "LO" or "HI."

Windshield Wiper Motor Drive Circuit:

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".

TECHNICAL DESCRIPTION (COMMENT)
This system may be at fail-safe mode as the SWS communication line is defective. If the system can not receive any signal from the column switch (windshield wiper and washer switch) due to a open circuit in the SWS communication line or other reasons, the system will enter the fail-safe mode when the ignition switch is at the "ACC" position.

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

DIAGNOSIS

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

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









CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool 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 "COLUMN ECU" and "FRONT ECU"?
"OK" are displayed for all the items : Replace the front-ECU. Check that the windshield wiper works normally.
"NG" is displayed on the "COLUMN ECU" menu : Refer to Inspection Procedure A-2 "Communication with column switch (column-ECU) is impossible."
"NG" is displayed on the "FRONT ECU" menu : Refer to Inspection procedure A-4 "Communication with front-ECU is impossible."