Diagnostic Item 2

DIAGNOSTIC ITEM 2: Malfunction Of The ETACS-ECU.

CAUTION: When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.

FUNCTION
When the CAN bus diagnosis is carried out, the scan tool sets communication "OK" flags in the patch between the ETACS-ECU and active other ECUs. If a commutation "OK" flag is not set for the ECUs other than the ETACS-ECU, this diagnosis result will be set.

TROUBLE JUDGEMENT CONDITIONS
If no communication flags are set for the ECUs (on the CAN-B or CAN-C lines) other than the ETACS-ECU, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINT
Malfunction of the ETACS-ECU

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

Recheck for other system diagnostic trouble code.

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.

Check whether ETACS-ECU-related DTC is set.







1. Connect scan tool MB991958 to the data link connector
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.


Q: Is the DTC set?

YES (The DTC other than the U code is set.) : Troubleshoot the ETACS-ECU. Refer to ETACS-ECU. Diagnostic Trouble Code Descriptions

YES (Only U-code DTC is set.) : Check the power supply circuit of the ETACS-ECU. Refer to ETACS-ECU. Trouble Symptom Chart

NO (The DTC is not set.) : Check the power supply circuit of the ETACS-ECU. Refer to ETACS-ECU. Trouble Symptom Chart