Inspection Procedure H-2

Rear Wiper and Washer: Rear Wiper Does Not Stop At the Predetermined Park Position

Rear Wiper Motor Drive Circuit
- Refer to Inspection Procedure H-1.

CIRCUIT OPERATION
A signal from the rear wiper switch is sent through the column-ECU inside the column switch to the ETACS-ECU. The signal turns on the relay inside the ETACS-ECU to operate the rear wiper motor.

TECHNICAL DESCRIPTION (COMMENT)
The rear wiper motor or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the rear wiper motor
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

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

STEP 1. Check method of the Input signal

Q: Which Is to be used, the scan tool or the voltmeter to check the Input signal?
Scan tool MB991502 : Go to Step 2.
Voltmeter: Go to Step 3.

STEP 2. Check the input signal (by using scan tool MB991502).
Check that the rear wiper auto-stop signal is sent to the ETACS-ECU.

NOTE: Whenever the rear wiper begins to work, a signal is sent to the ETACS-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.




1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.

Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?

YES: Replace the ETACS-ECU. The rear wiper should stop at the predetermined park position.

NO: Check the rear wiper auto-stop signal input circuit. Refer to Inspection Procedure O-8.

STEP 3. Check the input signal (by using a voltmeter).
Check that the rear wiper auto-stop signal is sent to the ETACS-ECU.

NOTE: Whenever the rear wiper begins to work, a signal is sent to the ETACS-ECU




1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.

Q: Does the voltmeter Indicator deflect?

YES: Replace the ETACS-ECU. The rear wiper should stop at the predetermined park position.

NO: Check the rear wiper auto-stop signal input circuit. Refer to Inspection Procedure O-8.