Combination Meter Assembly
DTC U1073: Bus OffCAUTION:
- If DTC U1073 is set in the combination meter, always diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
CIRCUIT OPERATION
Some instruments of the combination meter are linked to the CAN bus line. Both the combination meter and the powertrain control module have a terminator resistor.
DTC SET CONDITION
If the combination meter ceases communicating once (i.e. bus off) and then returns to it, the combination meter will not communicate for five minutes immediately after that point. This five minute period is called "Penalty mode." Immediately after the combination meter returns to communication, the DTC is set.
TECHNICAL DESCRIPTION (COMMENT)
The wiring harness or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the combination meter may be defective.
TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- Malfunction of combination meter
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. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
Q: Is the check result satisfactory?
YES : Go to Step 2.
NO : Repair the CAN bus lines.
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace combination meter.
NO : An intermittent malfunction is suspected.