Inspection Procedure O-16

INSPECTION PROCEDURE O-16: The windshield intermittent wiper interval adjusting knob signal is not sent to the ETACS-ECU.






CIRCUIT OPERATION
The ETACS-ECU calculates the windshield intermillent 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
- The column 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: 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 kilohm ("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 the column switch connector C-203 and ETACS-ECU connector C-318 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is column switch connector C-203 and ETACS-ECU connector C-318 in good condition?

YES : Go to Step 3.

NO : Repair or replace the damaged component(s). 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 wiring harness between column switch connector C-203 (terminal 6) and ETACS-ECU connector C-318 (terminal 66).

Q: Is the wiring harness between column switch connector C-203 (terminal 6) and ETACS-ECU connector C-318 (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. 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 : No action is necessary and testing is complete.

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.