Radio and CD Player

DTC U0168: WCM/KOS CAN time-out

CAUTION:

- If DTC U0168 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION

If the signal from KOS-ECU [vehicles with KOS] or WCM [vehicles with WCM] cannot be received, the radio and CD player sets DTC U0168.

JUDGMENT CRITERIA

With the ignition switch in the ON position, system voltage between 10 - 16 V
(data from ETACS-ECU), power supply fuse(IOD fuse) is OK, or odometer value is 80.5 km (50 miles) or more, and the communication with KOS-ECU [vehicles with KOS] or WCM [vehicles with WCM] cannot be established for 2,500 ms or more, the radio and CD player determines that a problem has occurred.

TROUBLESHOOTING HINTS

- Malfunction of CAN bus line may be defective.
- Malfunction of the KOS-ECU may be defective.[ vehicles with KOS]
- Malfunction of the WCM may be defective.[ vehicles with WCM]
- Malfunction of radio and CD player may be defective.

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. Using scan tool MB991958, diagnose the CAN bus line.





(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) Scan Tool Testing and Procedures."
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the CAN bus line found to be normal?

YES Go to Step 2.

NO Repair the CAN bus line CAN Bus Diagnostics Chart).

STEP 2. Using scan tool MB991958, read the KOS-ECU [vehicles with KOS] or WCM [vehicles with WCM] diagnostic trouble code.

Check again if the DTC is set to the KOS-ECU [vehicles with KOS] or WCM [vehicles with WCM].

Q. Is the DTC set?

YES Troubleshoot the KOS or WCM Keyless Operation System (KOS) [KOS] or Diagnosis Wireless Control Module (WCM) [WCM]).
NO Go to Step 3.
STEP 3. Recheck for diagnostic trouble code.

Check again if the DTC is set to the radio and CD player.

(1)Erase the DTC.

(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.

(3)Check if DTC is set.

(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

YES Replace the radio and CD player.
NO The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).