Inspection Procedure H-2

Rear Wiper Motor Drive Circuit:

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:
MB991223: Test Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness

Check the input signal.
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 "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Turn the ignition switch to "LOCK" (OFF) position.
2. Connect scan tool MB991502 to the data link connector.
3. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.





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.
If a defect appears, check the rear wiper auto-stop signal input circuit. Refer to Inspection Procedure O-8.
If no defect appears, replace the ETACS-ECU.
The rear wiper should stop at the predetermined park position.