Inspection Procedure M-7

INSPECTION PROCEDURE M-7: Column switch: ETACS-ECU does not receive any signal from the windshield mist wiper switch, the windshield intermittent wiper switch, the windshield low-speed wiper switch, the windshield high-speed wiper switch, the rear wiper switch, the windshield washer switch or the rear washer switch.

NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor." How to Use SWS Monitor

Wiper And Washer Switch Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the windshield wiper/washer and rear wiper/washer according to signal from the wiper and washer switch.

TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the windshield wiper/washer and rear wiper/washer do not work normally.

TROUBLESHOOTING HINTS
- The column switch may be defective (wiper and washer switch)
- The ETACS-ECU may be defective

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
- MB991813: SWS Monitor Kit
- MB991806: SWS Monitor Cartridge
- MB991812: SWS Monitor Harness (For Column-ECU)
- MB991822: Probe Harness

STEP 1. Use scan tool MB991958 to select "ECU COMM Check" on the SWS monitor display.

Check the column-ECU.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. Connect special tool MB991910 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.




1. Connect the special tool. Refer to "How to connect SWS monitor." How to Connect SWS Monitor
2. Turn the ignition switch to the "ON" position.
3. Operate the scan tool according to the procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."

4. Scan tool (M.U.T.-III) should show "OK" on the "ECU COMM Check" menu for the "COLUMN ECU" menu.

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

YES : Go to Step 2.

NO : Refer to INSPECTION PROCEDURE A-2 "Communication with the column switch (column-ECU) is not possible." Inspection Procedure A-2

STEP 2. Check the wiper and washer switch.




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






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

YES : Go to Step 3.

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

STEP 4. Replace the column switch.

1. Replace the column switch.
2. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the column switch (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 is necessary and testing is complete.

NO : Replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Refer to Chassis Electrical, Encrypted Code Registration Criteria Table. If the equipment described in "CIRCUIT OPERATION" work normally, the input signal from the column switch (wiper and washer switch) should be normal.