Inspection Procedure F-4

TECHNICAL DESCRIPTION (COMMENT)
The sunroof motor assembly deactivates the sunroof timer if the SWS communication line is open circuited. In addition, when the doors are opened if the door switch circuit is defective and the timer is on, the sunroof timer should not operate normally.

TROUBLESHOOTING HINTS
- Malfunction of the driver's or passenger's door switch
- Malfunction of the sunroof motor assembly e Damaged harness wires or connectors

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

STEP 1. Check the input signal.
Check the input signals from the following switches.
- Driver's and passenger's door switch
- Sunroof switch

NOTE: It can be determined whether the harness wires between the sunroof motor assembly and the ETACS-ECU is defective or not by checking the SWS communication line.






CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "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.





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.
If one of the input signal checks shows a defect, check the relevant input circuit.
If no defect appears, replace the sunroof motor assembly. The sunroof timer should work normally.