U1606

DTC U1606: M-BUS error

CAUTION:
- If DTC U1606 is set in the multi-center display, always diagnose the CAN bus lines.
- Whenever the multi-center display unit (middle grade type) is replaced, ensure that the power supply circuit and the ground circuit are normal.

DTC SET CONDITION
With the ignition switch in the "ACC"or "ON" position, if the communication between the radio, CD player and CD changer and the multi-center display unit (middle grade type) cannot be made for 30 seconds or more, or if there is a problem in the communication data, DTC U1606 will be set.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble
- The radio, CD player and CD changer or the multi-center display unit (middle grade type) may be defective.

Past trouble
- Carry out diagnosis with particular emphasis on connector(s) or wiring harness between the radio, CD player and CD changer and the multi-center display unit (middle grade type).

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- Malfunction of radio, CD player and CD changer
- Malfunction of multi-center display unit (middle grade type)

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle 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 : Check the communication line between the multi-center display unit (middle-grade type) and the radio, CD player and CD changer. Perform Inspection Procedure 5: On the audio screen, "COMMUNICATION ERROR" cannot proceed to next screen (middle grade type). (Refer to Inspection Procedure 5. Inspection Procedure 5 After the diagnosis, go to Step 2.

NO : Repair the CAN bus lines. On completion, go to Step 2.

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 multi-center display unit (middle grade type).

NO : A poor connection, open circuit or other intermittent malfunction is present in the lines between the radio, CD player and CD changer and the multi-center display unit (middle grade type).