Automatic Transmission
DTC U0100: ECM Time-out
DESCRIPTIONS OF MONITOR METHODS
- Open circuit or short circuit occurs in the CAN communication line (CAN_H, CAN_L).
- Reception from ECM becomes impossible for 0.5 seconds or more.
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)
- P0712: Malfunction of the transmission fluid temperature sensor (Short circuit)
- P0715: Malfunction of the Input shaft speed sensor system
- P0731: Malfunction of the 1st gear incorrect ratio
- P0732: Malfunction of the 2nd gear incorrect ratio
- P0733: Malfunction of the 3rd gear incorrect ratio
- P0734: Malfunction of the 4th gear incorrect ratio
- P0735: Malfunction of the 5th gear incorrect ratio
- P0729: Malfunction of the 6th gear incorrect ratio
- P0741: Malfunction of the Malfunction of the Torque converter clutch system (Stuck off)
- P0742: Malfunction of the Torque converter clutch system (Stuck on)
- P0846: Malfunction of the 2-6 brake pressure switch system
- P0876: Malfunction of the High clutch pressure switch system
- P0988: Malfunction of the Low-reverse brake pressure switch system
- P1705: Malfunction of the Throttle position sensor information (engine)
- P1706: Malfunction of the Accelerator pedal position information
Sensor (The sensor below is determined to be normal)
- Transmission fluid temperature sensor
- Input shaft speed sensor
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Check Conditions
- TCM is started: more than 1.05 seconds.
Judgement Criteria
- CAN communication with ECM: fail.
OBD-II DRIVE CYCLE PATTERN
With the ignition switch ON, maintain the status for 10 seconds or more.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
- Damaged harness or connector
- Malfunction of the CAN communication
- Malfunction of the ECM
- Malfunction of the TCM
DIAGNOSIS
STEP 1. Check the CAN communication system malfunction.
- Check that the CAN system-related DTC code other than U0100 is set.
- Check if the CAN-related DTC is set with ECM.
- Check if the failure related to the engine occurs.
Q. Is the check result normal?
YES Go to Step 2.
NO Repair or replace the failure section.
STEP 2. Check the CAN communication lines.
[C-38 TCM connector (vehicle side, disconnected)]
Between C-38 terminal No. 10, 11 and the CAN communication lines of ECM: Continuity exists.
When the continuity check result is OK, check that the wiring harness is not shorted to the body and other wiring harness. Also, check for a short circuit between the twisted pair cables.
Q. Is the check result normal?
YES Go to Step 3.
NO Repair or replace the failure section.
STEP 3. Check ECM, the TCM connector pin terminal, and the connection status.
Q. Is the check result normal?
YES Repair or replace the failure section.
NO Replace the TCM.