Inspection Procedure F-3

Sunroof: Sunroof Timer Function does not Work Normally.

NOTE: This troubleshooting requires use of scan tool MB991502 and SWS monitor kit MB991862. For details of how to use the SWS monitor, refer to "How to use SWS monitor."

Sunroof Timer Function:

CIRCUIT OPERATION
- The sunroof timer function works according to the signals from the following switches:
- Ignition switch (IG1): OFF
- Front door switch: OFF

- Vehicle condition
- Ignition switch: LOCK position
- Driver's and front passenger's door: Closed

- When a front door is opened and closed while the sunroof timer function is on, the sunroof operative duration will be changed.

TECHNICAL DESCRIPTION (COMMENT)
Is the sunroof timer function does not work normally, the input circuits from the switches described in "CIRCUIT OPERATION", the sunroof motor assembly, the ETACS-ECU or the SWS communication line may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the driver's or front passenger's door switch
- Malfunction of the sunroof motor assembly
- 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 following ECUs:
- ETACS-ECU
- sunroof-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 "LOCK" (OFF) position, scan tool MB991502 should show "OK" on the "ECU CHECK" menu.

Q: Are "OK" displayed on the "ETACS ECU" and "SUNROOF ECU" menu?

"OK" are displayed for all the items : Go to Step 2.
"NG" is displayed on the "ETACS ECU" menu : Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is impossible."
"NG" is displayed on the "SUNROOF ECU" menu : Refer to Inspection Procedure A-6 "Communication with sunroof motor (sunroof-ECU) is impossible."







STEP 2. Check the input signal by using service data of the SWS monitor.
Turn the ignition switch to the "OFF" position to check the input signals from the following switches.




Select "SUNROOF - SUNROOF OPE." (FUNCTION DIAG.), and check that normal conditions are displayed on the items described in the table.

Q: Are normal conditions displayed on the "IG SW (IG1)" and "S/R ECU ACK"?

YES: Replace the sunroof motor assembly. Check that the sunroof timer function works normally.

NO:
- Normal condition is not displayed on the "IG SW(IG1)": Refer to Inspection Procedure O-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."
- Normal condition is not displayed on the "S/R ECU ACK": Replace the sunroof motor assembly. Check that the sunroof timer function works normally.