Inspection Procedure O-19

Windshield Intermittent Wiper Intervals Adjusting Knob Input Circuit:

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

TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval adjusting knob is detective, the windshield intermittent wiper interval can not be adjusted.

TROUBLESHOOTING HINTS
- Malfunction of the column switch (windshield wiper and windshield washer switch)
- 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




STEP 1. Check the windshield intermittent wiper interval adjusting knob.
Check the resistance at terminal numbers 27 and 28. The resistance should change smoothly from approximately 0 Ohms ("FAST" position) to approximately 1 kOhms ("SLOW" position).

If the windshield intermittent wiper interval adjusting knob is damaged, replace the column switch (windshield wiper and windshield washer).

Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.

If the windshield intermittent wiper interval adjusting knob is in good condition, go to Step 2.







STEP 2. Check the column switch connector C-86 and ETACS-ECU connector C-111 for damage.
If the column switch connector C-86 and ETACS-ECU connector C-111 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.

If the connectors are in good condition, go to Step 3.







STEP 3. Check the harness wire between column switch connector C-86 and ETACS-ECU connector C-111.
If the harness wire between column switch connector C-86 and ETACS-ECU connector C-111 is damaged, repair it. Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.

If the harness wire is in good condition, replace the ETACS-ECU or column switch.
Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.