Inspection Procedure L-6

Column switch: ETACS-ECU does not Receive Any Signal from Windshield Mist Wiper Switch, Windshield Intermittent Wiper Switch, Windshield Low-speed Wiper Switch, Windshield High-speed Wiper Switch, Windshield Washer Switch, Rear Wiper Switch or Rear Washer Switch

Windshield Wiper And Washer Switch Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the following equipment or functions according to signal from the column switch (windshield wiper and washer switch):
- Windshield wiper and washer
- Rear wiper and washer

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment, which is described in "CIRCUIT OPERATION", does network normally.

TROUBLESHOOTING HINTS
- Malfunction of the column switch (windshield wiper and 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)
- MB991862: SWS monitor kit








STEP 1. Use scan tool to select "ECU CHECK" on the SWS monitor display.

Check the column-ECU.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502. Also connect SWS monitor kit MB991862 after turning on scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Connect SWS monitor kit MB991862 to the column switch connector.
3. When the ignition switch is turned to the "ON" position, scan tool MB991502 should show "OK" on the "COLUMN ECU" menu.

Q: Is "OK" displayed on the "COLUMN ECU" menu?

YES: Go to Step 2.

NO: Refer to Inspection Procedure A-2 "Communication with column switch (column-ECU) is impossible."







STEP 2. Check the windshield wiper and washer switch.

Remove the windshield wiper and washer switch. Then check continuity between the switch terminals.

Q: Are the windshield wiper and washer switch in good condition?

YES: Go to Step 3.

NO: Replace the column switch. If the equipment, which are described in "CIRCUIT OPERATION", work normally, the input signal from the column switch (windshield wiper and washer switch) should be normal.







STEP 3. Check the switch body.

Remove the turn-signal light and lighting switch and windshield wiper and washer switch. Then check continuity between the switch body terminals.

Q: Is the switch body in good condition?

YES: Go to Step 4.

NO: Replace the column switch. If the equipment, which are described in "CIRCUIT OPERATION", work normally, the input signal from the column switch (windshield wiper and washer switch) should be normal.

STEP 4. Replace the ECU.

1. Replace the column switch (turn-signal light and lighting switch).
2. If the equipment, which are described in "CIRCUIT OPERATION", work normally, the input signal from the column switch (windshield wiper and washer switch) should be normal.

Q: Does the column switch (windshield wiper and washer switch) send a normal signal to the ECU?

YES: No action to be taken.

NO: Replace the ETACS-ECU. If the equipment, which are described in "CIRCUIT OPERATION", work normally, the input signal from the column switch (windshield wiper and washer switch) should be normal.