DTC U1109: Column SW LIN timeout

caution

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

TROUBLE JUDGEMENT

The ETACS-ECU receives signal from the column switch. If signal cannot be received at all, DTC U1109 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

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

Past trouble

If DTC U1109 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the LIN bus line between the column switch and the ETACS-ECU, and the power supply system of the column switch.

TROUBLESHOOTING HINTS

The lighting switch 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-301 and column switch connector C-201 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are ETACS-ECU connector C-301 and column switch connector C-201 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-301 (terminal 1) and column switch connector C-201 (terminal 3).

Check the communication lines for open circuit and short circuit.

note

Also check joint connector C-02 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-02 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector Inspection

Q. Is the wiring harness between ETACS-ECU connector C-301 (terminal 1) and column switch connector C-201 (terminal 3) 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 lighting switch.

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