Inspection Procedure O-10

Sunroof Switch: The ETACS-ECU does not Receive Any Signal from the Up, Open or Close/down Switch.

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 Switch Input Circuit:

Connector:

CIRCUIT OPERATION
The ETACS-ECU receives a signal through the sunroof motor assembly via the SWS communication line from the sunroof switch, and sends a signal to the data link connector.

TECHNICAL DESCRIPTION (COMMENT)
If the SWS communication line between the sunroof motor assembly and the ETACS-ECU is defective, the ETACS-ECU cannot identify the input signal from the sunroof switch even if the sunroof is normal.

TROUBLESHOOTING HINTS
- Malfunction of the sunroof switch
- Malfunction of the sunroof motor assembly
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS Monitor Kit

STEP 1. Check the sunroof operation.

Q: Does the sunroof work normally?

YES: Go to Step 2.

NO: Refer to Inspection Procedure F-1 "Sunroof does not operate."







STEP 2. Check sunroof motor assembly connector D-06 and ETACS-ECU connector C-118 for damage.

Q: Are sunroof motor assembly connector D-06 and ETACS-ECU connector C-118 in good condition?

YES: Go to Step 3.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. If the sunroof operates normally, it indicates that a correct signal is sent from the sunroof switch.










STEP 3. Check the wiring harness between sunroof motor assembly connector D-06 and ETACS-ECU connector C-118.

NOTE: Also check intermediate connectors C-31 and joint connector C-78. I/intermediate connector C-31 or joint connector C-78 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between sunroof motor assembly connector D-06 and ETACS-ECU connector C-118 in good condition?

YES: Go to Step 4.

NO: Repair the wiring harness. If the sunroof operates normally, it indicates that a correct signal is sent from the sunroof switch.

STEP 4. Replace the ECU.
1. Replace the sunroof motor assembly.
2. If the sunroof operates normally, it indicates that a correct signal is sent from the sunroof switch.

Q: Does the ETACS-ECU receive correct signals from the sunroof switch?

YES: No action to be taken.

NO: Replace the ETACS-ECU. If the sunroof operates normally, it indicates that a correct signal is sent from the sunroof switch.