Inspection Procedure F-2

INSPECTION PROCEDURE F-2: Sunroof: Any of the sunroof switch positions is defective.

TECHNICAL DESCRIPTION (COMMENT)
The sunroof switch or the sunroof motor assembly may be defective.

TROUBLESHOOTING HINTS
- The sunroof switch may be defective.
- The sunroof motor assembly may be defective.
- The wiring harness or connectors may have loose, corroded or damaged terminals, or terminals pushed back in the connector.

DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check method of the input signal.

Q: Which is to be used, the scan tool or a voltmeter to check the input signal?
Scan tool MB991502 : Go to Step 2.
Voltmeter : Go to Step 3.

STEP 2. Check the input signal (using the scan tool MB991502).
Check the input signals from the sunroof switch.

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.




1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.

Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?

YES : Replace the sunroof motor assembly. The sunroof should work normally in all of the switch positions.

NO : Scan tool MB991502 does not sound when the sunroof switch is turned from "OFF" to "OPEN/TILT UP" or "CLOSE/TILT DOWN": Refer to Inspection Procedure O-18 "The open/tilt up or close/tilt down switch signal is not sent to the ETACS-ECU."

STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the sunroof switch.




1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.

Q: Does the voltmeter indicator deflect?

YES : Replace the sunroof motor assembly. The sunroof should work normally in all of the switch positions.

NO : Scan tool MB991502 does not sound when the sunroof switch is turned from "OFF" to "OPEN/TILT UP" or "CLOSE/TILT DOWN": Refer to Inspection Procedure O-18 "The open/tilt up or close/tilt down switch signal is not sent to the ETACS-ECU."