Inspection Procedure G-4

TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU calculates the intermittent wiper interval, and sends a signal to the front-ECU through the SWS communication line. If the signal is defective, the front-ECU will ignore the signal and set the intermittent wiper interval to four seconds.

TROUBLESHOOTING HINTS
- Malfunction of the column switch (windshield wiper and windshield washer switch)
- Malfunction of the ETACS-ECU
- Malfunction of the front-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 the input signals from the windshield intermittent wiper interval adjusting knob.

NOTE: If the windshield intermittent wiper interval adjusting knob is rotated from "FAST" to "SLOW" when the ignition switch is at the "ON" position, the ETACS-ECU will send a signal around the medium knob position.






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. 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.





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 input signal circuit from the windshield intermittent wiper interval adjusting knob. Refer to Inspection Procedure O-19.
If no defect appears, replace the front-ECU or ETACS-ECU. The windshield intermittent wiper interval should be changed.