Satellite Radio Tuner

DTC U0019: Bus off (CAN-B)

CAUTION:
If DTC U0019 is set, be sure to diagnose the CAN bus line.

CAUTION:
When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION

If the CAN-B circuit malfunction occurs, the satellite radio tuner sets DTC U0019.

JUDGMENT CRITERIA

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

TROUBLESHOOTING HINTS

The satellite radio tuner, power supply for the satellite radio tuner, earth circuit, or CAN bus line may have a problem.

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.

Use scan tool MB991958 to diagnose the CAN bus lines.





(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 to "ON" position.
(3)Diagnose the CAN bus line.

Q. Is the check result normal?

YES Go to Step 2.

NO Repair the CAN bus line. CAN Bus Diagnostics Chart.) On completion, go to Step 2.

STEP 2. Check whether the scan tool MB991958 can communicate with the satellite radio tuner.

Q. Is the check result normal?

YES Erase the diagnosis code. The procedure is complete.
NO Check the power supply circuit of the satellite radio tuner, and repair if necessary.