[Previous] [Next]

DTC U0100: Engine control module CAN timeout



caution
  • If DTC U0100 is set to the ETACS-ECU, always diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the communication circuit is normal.

TROUBLE JUDGMENT


If the signal from engine control module cannot be received, the ETACS-ECU sets DTC U0100.

JUDGMENT CRITERIA


After the following statuses continue to be true for 5 seconds, if the communication with the engine control module cannot be established for 0.6 second or more, the ETACS-ECU determines that a problem has occurred.


TROUBLESHOOTING HINTS




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.



(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. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the CAN bus line found to be normal?

Go to Step 2.

Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).

STEP 2. Using scan tool MB991958, read the engine control module diagnostic trouble code.


Check if DTC is set to the engine control module.

Q. Is the DTC set?

Troubleshoot the engine (Refer to GROUP 13A, Diagnostic Trouble Code Chart <2.0 L engine non-turbo>, GROUP 13B, Diagnostic Trouble Code Chart <2.0 L engine turbo> or GROUP 13C, Diagnostic Trouble Code Chart <2.4 L engine>).
Go to Step 3.

STEP 3. Using scan tool MB991958, read the CVT diagnostic trouble code.


Check if DTC U0100 is set to the CVT-ECU.

Q. Is the DTC set?

Go to Step 4.
Go to Step 5.

STEP 4. Recheck for diagnostic trouble code.


Check again if the DTC is set to the ETACS-ECU.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

Replace the engine control module.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the engine control module and the ETACS-ECU (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

STEP 5. Recheck for diagnostic trouble code.


Check again if the DTC is set to the ETACS-ECU.
(1)Erase the DTC.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if DTC is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

Replace the ETACS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the engine control module and the ETACS-ECU (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).