Electronic Control Modules

DTC U0101: Transmission Control Module Time-Out

CAUTION:
- If the ECM output the DTC U0101, make sure to diagnose the CAN bus line.
- Before replacing the ECU, make sure that the communication circuit is operating normally.

DESCRIPTIONS OF MONITOR METHODS
There is no data from TCM for the specified time. (TCM detect communication error with ECM.)

MONITOR EXECUTION
- Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable

Sensor (The sensor below is determined to be normal)
- Not applicable

DTC SET CONDITIONS

Check Conditions
- After 4 seconds have passed since the ignition switch was turned to "ON" position.
- Battery positive voltage is between 10 and 16.5 volts.

Judgement Criterion
- Unable to receive TCM signals through the CAN bus line 4 seconds.

OBD-II DRIVE CYCLE PATTERN
None.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- CAN line harness damage or connector damage.

DTC SET CONDITIONS

Logic Flow Chart:

Logic Flow Chart

DIAGNOSIS

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




STEP 1. Using scan tool MB991958, diagnose CAN bus line.

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.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Diagnose CAN bus line.
4. Turn the ignition switch the "LOCK" (OFF) position.

Q: Is the CAN bus line normal?

YES: It can be assumed that this malfunction is intermittent.

NO: Repair the CAN bus line. Refer to Can bus Diagnostics Table. Then go to Step 2.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

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

Q: Is DTC U0101 set?

YES: Retry the troubleshooting.

NO: The inspection is complete.