U1206

DTC U1206: Flag invalid

CAUTION:
If DTC U1206 is set in the combination meter, diagnose the CAN main bus line.

TROUBLE JUDGMENT

When the ignition switch is in the "LOCK" (OFF) position, the combination meter receives door-open signal or communication standby instruction from the ETACS-ECU and keeps CAN communication. If there is a contradiction between these two signals, DTC U1206 will be set.

COMMENTS ON TROUBLE SYMPTOM

Current trouble

- The door switch system of the ETACS-ECU, the ETACS-ECU, or the combination meter may be defective.
Past trouble

- Carry out diagnosis with particular emphasis on connector(s) or wiring harness between the ETACS-ECU and the door switch, and the power supply system to the ETACS-ECU. For diagnosis procedures, refer to "How to cope with past trouble" How to Cope With Intermittent Malfunctions ).

POSSIBLE CAUSES

- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
- Malfunction of ETACS-ECU
- Malfunction of combination meter

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

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 to the data link connector.
(2)Turn the ignition switch to "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result satisfactory?

YES Go to Step 2.

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

STEP 2. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.

Check that the ETACS-ECU sets a diagnostic trouble code.





(1)Turn the ignition switch to "ON" position.
(2)Read the diagnostic trouble code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

YES Diagnose the SWS system by referring to Simplified Wiring System (SWS).

NO Go to Step 3.

STEP 3. Recheck for diagnostic trouble code.

When the ETACS-ECU is replaced, register the encrypted code. Encrypted Code Registration Criteria Table, and then check that the diagnostic trouble code is not reset.





(1)Turn the ignition switch to "ON" position.
(2)Erase the diagnostic trouble code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to "ON" position.
(5)Check if the diagnostic trouble code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result satisfactory?

YES The procedure is complete.

NO Replace the combination meter.