Inspection Procedure F-6

Windshield Wiper and Washer: The windshield intermittent wiper interval is not changed according to the vehicle speed.

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

Windshield Intermittent Wiper Interval Adjusting Knob Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval is not changed according to the vehicle speed, the ETACS-ECU or the front-ECU may be defective.

TROUBLESHOOTING HINTS
- The ETACS-ECU may be defective
- The front-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
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS monitor kit




STEP 1. Check the input signal by using the pulse check mode of the monitor.

Check the input of the vehicle speed signal:

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.

1. Connect scan tool MB991502 to the data link connector.
2. Check that scan tool MB991502 sounds when the vehicle speed exceeds 10 km/h (6.2 mph).

Q: Does scan tool MB991502 sound when the vehicle speed exceeds 10 km/h (6.2 mph)?

YES: Go to Step 2.

NO: Refer to Inspection Procedure N-10 "ETACS-ECU does not receive vehicle speed signal."







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
- Windshield wiper switch: INT
- Intermittent wiper control: slow side (mph)

Operate the MUT-II according to the procedure below to display "F.WIPER INT."
1. Select "SYSTEM SELECT."
2. Select "SWS."
3. Select "SWS MONITOR."
4. Select "FUNCTION DIAG."
5. Select "WIPER."
6. Select "F.WIPER INT."




Check that normal conditions are displayed on the items described in the table.

NOTE: Also check that the wiper interval changes smoothly when the vehicle is accelerated from 0 km/h (0 mph) to 25 km/h (15.5 mph).

Q: Does the value change within the normal range when the windshield intermittent wiper interval adjusting knob is rotated?

YES: Replace the front-ECU. The windshield intermittent wiper interval should change according to the vehicle speed.

NO: Replace the ETACS-ECU. The windshield intermittent wiper interval should change according to the vehicle speed.