Combination Meter

DTC U0019: Bus off (CAN-B)

CAUTION:

- If DTC U0019 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 CAN-B circuit malfunction occurs, the combination meter sets DTC U0019.

JUDGEMENT CRITERIA

With the ignition switch at the ON position and the system voltage at 10 - 16 volts (data from ETACS-ECU), if the combination meter becomes unable to transmit data normally due to the CAN-B bus circuit malfunction, the combination meter determines that a problem has occurred.

TROUBLESHOOTING HINTS

The CAN bus line 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.Recheck for diagnostic trouble code.

Check again if the DTC is set to the combination meter.





(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) Reading and Clearing Diagnostic Trouble Codes."
(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 Go to Step 2.

NO The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).

STEP 2. Using scan tool MB991958, diagnose the CAN bus line.

(1)Turn the ignition switch to the "ON" position.

(2)Diagnose the CAN bus line.

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

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

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Repair the CAN bus line CAN Bus Diagnostics Chart).