Inspection Procedure O-17

The windshield intermittent wiper interval adjusting knob signal is not sent to the ETACS-ECU.

Windshield Intermittent Wiper Interval 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 defective, the windshield intermittent wiper interval can not be adjusted.

TROUBLESHOOTING HINTS
- Malfunction of the column 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 and column switch body.
Check the resistance at terminal numbers 27 and 28. The resistance should change smoothly from approximately 0 Ohm ("FAST" position) to approximately 1 kOhm ("SLOW" position).

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

YES: Go to Step 2.
NO: Replace the it. Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.







STEP 2. Check column switch connector C-203 and ETACS-ECU connector C-313 for damage.

Q: Is column switch connector C-203 and ETACS-ECU connector C-313 in good condition?

YES: Go to Step 3.
NO: 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.







STEP 3. Check the harness wire between column switch connector C-203 and ETACS-ECU connector C-313.

Q: Is the harness wire between column switch connector C-203 and ETACS-ECU connector C-313 in good condition?

YES: Go to 4.
NO: 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.

STEP 3. Replacement of ECU
1. Replace the ETACS-ECU.
2. Check that the input signal from the windshield intermittent wiper interval adjusting knob can be checked and the wiper interval can be adjusted.

Q: Is the input signal from the windshield intermittent wiper interval adjusting knob input normally?

YES: There is no action to be taken.
NO: Replace the 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.