Inspection Procedure H-3

Rear Wiper and Washer: When the shift lever is moved to reverse "R" position during the rear wiper operation, the rear wiper does not operate at the continuous mode.

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."

"R" Position During Rear Wiper Operation Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the rear wiper consecutively approximately twice when the shift lever is moved to reverse "R" position while the rear wiper is turned on.

TECHNICAL DESCRIPTION (COMMENT)
If the rear wiper does not work consecutively approximately twice, the backup light switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Trouble in input signal system
- 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 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
- MB991911: M.U.T.-III Main Harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness

STEP 1. Verify rear wiper operation.

Q: Does the rear wiper operate?

YES: Go to Step 2.

NO: Refer to Inspection Procedure H-1 "Rear wiper does not work at all."

STEP 2. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.

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 MB991911 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."
2. Turn the ignition switch to the "ON" position.
3. Turn the rear wiper switch to the "ON" position.
4. Shift the shift lever to the reverse "R" position.
5. Operate scan tool MB991958 according to the procedure below to display "REV. INTERLOCK."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "REAR WIPER."
g. Select "REV INTERLOCK."




6. Check that normal conditions are displayed on the item described in the table.

Q: Does scan tool MB991958 display the item "PNP SW (R)" as normal condition?

YES: Replace the ETACS-ECU. When the shift lever is moved to the reverse "R" position, the rear wiper should operate consecutively approximately twice.

NO: Refer to Inspection Procedure N-4 "The ETACS-ECU does not receive any signal from the backup light switch."