U1206
DTC U1206: Flag invalidCAUTION: 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.
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: 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 : Go to Step 2.
NO : Repair the CAN bus lines. On completion, go to Step 4.
STEP 2. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.
Check that the ETACS-ECU sets a DTC.
Q: Is the DTC set?
YES : Diagnose the SWS system by referring to Diagnostic Trouble Code Descriptions.
NO : Go to Step 3.
STEP 3. Replace the ETACS-ECU and then recheck the DTC.
Replace the ETACS-ECU, and then check that the DTC is not reset.
Q: Is the DTC set?
YES : Replace combination meter and then go to step 4.
NO : Go to Step 4.
STEP 4. 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 : Go to Step 1.
NO : The procedure is complete.