Inspection Procedure O-9

Column Switch: ETACS-ECU does not receive Any Signal from the Windshield Intermittent Wiper Interval Adjusting Knob.

Windshield Intermittent Wiper Interval Adjusting Knob Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU calculates the windshield intermittent wiper interval according to the position of the windshield intermittent wiper interval adjusting knob, which is incorporated in column switch (windshield wiper and washer switch).

TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval can not be adjusted, the column switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- The column switch (windshield wiper and washer switch) may be defective
- The ETACS-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
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface (V.C.I.)
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness

STEP 1. Check the windshield intermittent wiper interval adjusting knob.




1. Remove the windshield wiper and washer switch, and check at the switch side.
2. Measure the resistance value between terminals 27 and 28.The measured resistance should change smoothly from approximately 0 ohm ("FAST" position) to 1 kilo Ohm ("SLOW" position).

Q: Is the windshield intermittent wiper interval adjusting knob in good condition?

YES: Go to Step 2.

NO: Replace the column switch (windshield wiper and washer switch). If the wiper interval can be adjusted normally, it indicates that the windshield intermittent wiper interval adjusting knob should send a signal to the ECU.







STEP 2. Check column switch connector C-86 and ETACS-ECU connector C-118 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are column switch connector C-86 and ETACS-ECU connector C-118 in good condition?

YES: Go to Step 3.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. If the wiper interval can be adjusted normally, it indicates that the windshield intermittent wiper interval adjusting knob should send a signal to the ECU.







STEP 3. Check the wiring harness between column switch connector C-86 (terminal 6) and ETACS-ECU connector C-118 (terminal 66).

Q: Is the wiring harness between column switch connector C-86 (terminal 6) and ETACS-ECU connector C-118 (terminal 66) in good condition?

YES: Go to 4.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. If the wiper interval can be adjusted normally, it indicates that the windshield intermittent wiper interval adjusting knob should send a signal to the ECU.

STEP 4. Replace the ECU.

1. Replace the ETACS-ECU.
2. If the wiper interval can be adjusted normally, it indicates that the windshield intermittent wiper interval adjusting knob should send a signal to the ECU.

Q: Can input signal be confirmed when the windshield intermittent wiper interval adjusting knob is operated?

YES: No action is necessary and testing is complete.

NO: Replace the column switch (windshield wiper and washer switch). If the wiper interval can be adjusted normally, it indicates that the windshield intermittent wiper interval adjusting knob should send a signal to the ECU.