U0231

DTC U0231: Rain Light Sensor LIN Timeout [Vehicles With Auto Light Function]

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

Lighting Control Sensor LIN Communication Circuit:

TROUBLE JUDGMENT
The ETACS-ECU receives signal from the lighting control sensor. If signal cannot be received at all, DTC U0231 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble
- Connector(s) or wiring harness in the LIN bus lines between the lighting control sensor and the ETACS-ECU, the power supply system of the lighting control sensor, or the lighting control sensor 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 lighting control sensor and the ETACS-ECU, and the power supply system of the lighting control sensor.

TROUBLESHOOTING HINTS
- The lighting control sensor 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 lighting control sensor connector D-02 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q : Are ETACS-ECU connector C-316 and lighting control sensor connector D-02 in good condition?

YES : Go to Step 2.

NO : Repair or replace the damaged component(s).

STEP 2. Check the wiring harness between ETACS-ECU connector C-316 (terminal 1) and lighting control sensor connector D-02 (terminal 3).

Q : Is the wiring harness between ETACS-ECU connector C-316 (terminal 1) and lighting control sensor connector D-02 (terminal 3) in good condition?

YES : Go to Step 3.

NO : 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.






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.

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

YES : Replace the lighting control sensor.

NO : A poor connection, open circuit or other intermittent malfunction is present in the LIN bus lines between the lighting control sensor and the ETACS-ECU (Refer to General (Body and Chassis), How to Cope with Intermittent Malfunction).