Inspection Procedure O-7
INSPECTION PROCEDURE O-7: Column Switch: ETACS-ECU Does Not Receive Any Signal From The Variable Intermittent Wiper Control Switch.Windshield Intermittent Wiper Interval Adjusting Knob Input Circuit (Part 1):
Windshield Intermittent Wiper Interval Adjusting Knob Input Circuit (Part 2):
CIRCUIT OPERATION
The ETACS-ECU calculates the windshield intermittent wiper interval according to the position of the variable intermittent wiper control switch, which is incorporated in column switch (windshield wiper and washer switch).
TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval cannot be adjusted, the column switch or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- The column switch may be defective (windshield wiper and washer switch)
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The ETACS-ECU may be defective
DIAGNOSIS
Required Special Tool:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Check column switch connector C-309 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is column switch connector C-309 in good condition?
YES: Go to Step 2.
NO: Repair or replace the damaged component(s). If the wiper interval can be adjusted normally, the variable intermittent wiper control switch should send a signal to the ECU.
STEP 2. Check the variable intermittent wiper control switch.
1. Remove the windshield wiper and washer switch, and check at the switch side.
2. Measure the resistance value between terminals 3 and 6. The measured resistance should change smoothly from approximately 0 ohm ("FAST" position) to 1 kilo ohm ("SLOW" position).
Q: Is the variable intermittent wiper control switch in good condition?
YES: Go to Step 3.
NO: Replace the column switch (windshield wiper and washer switch). If the wiper interval can be adjusted normally, that the variable intermittent wiper control switch should send a signal to the ECU.
STEP 3. Check ETACS-ECU connector C-218 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-218 in good condition?
YES: Go to Step 4.
NO: Repair or replace the damaged component(s). If the wiper interval can be adjusted normally, that the variable intermittent wiper control switch should send a signal to the ECU.
STEP 4. Check the wiring harness between column switch connector C-309 (terminal 6) and ETACS-ECU connector C-218 (terminal 66).
- Check the communication lines for open circuit and short circuit.
Q: Is the wiring harness between column switch connector C-309 (terminal 6) and ETACS-ECU connector C-218 (terminal 66) in good condition?
YES: Go to Step 5.
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, the variable intermittent wiper control switch should send a signal to the ECU.
STEP 5. Replace the ECU.
1. Replace the ETACS-ECU.
2. If the wiper interval can be adjusted normally, the variable intermittent wiper control switch should send a signal to the ECU.
Q: Can input signal be confirmed when the variable intermittent wiper control switch 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, the variable intermittent wiper control switch should send a signal to the ECU.