DTC U0169: Sunroof LIN timeout <Vehicles with sunroof>

caution

Before replacing the ECU, ensure that the communication circuit is normal.

TROUBLE JUDGEMENT

The ETACS-ECU receives signal from the sunroof motor assembly (sunroof-ECU). If signal cannot be received at all, DTC U0169 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

Connector(s) or wiring harness in the LIN bus lines between the sunroof motor assembly and the ETACS-ECU, the power supply system of the sunroof motor assembly, or the sunroof motor assembly itself may be defective.

Past trouble

If DTC U0169 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the LIN bus line between the sunroof motor assembly and the ETACS-ECU, and the power supply system of the sunroof motor assembly.

TROUBLESHOOTING HINTS

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:

MB991958 Scan Tool (M.U.T.-III Sub Assembly)

MB991824: Vehicles Communication Interface (V.C.I.)
MB991827 M.U.T.-III USB Cable
MB991910 M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Check ETACS-ECU connector C-316 and sunroof motor assembly connector D-05 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are ETACS-ECU connector C-316 and sunroof motor assembly connector D-05 in good condition?

	Go to Step 2.

	Repair or replace the damaged component(s).

STEP 2. Check the wiring harness between ETACS-ECU connector C-316 (terminal 1) and sunroof motor assembly connector D-05 (terminal 7).

Check the communication lines for open circuit and short circuit.

Q. Is the wiring harness between ETACS-ECU connector C-316 (terminal 1) and sunroof motor assembly connector D-05 (terminal 7) in good condition?

	Go to Step 3.

	The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 3. Recheck for diagnostic trouble code.

Check again if the DTC is set to the ETACS-ECU.

(1)

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 scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)

."
(2)Erase the DTC.
(3)Turn the ignition switch to the "ON" position.
(4)Check if the DTC is set.
(5)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

Replace the sunroof motor assembly.

A poor connection, open circuit or other intermittent malfunction is present in the LIN bus lines between the sunroof motor assembly and the ETACS-ECU (Refer to GROUP 00, How to Cope with Intermittent Malfunction