DTC U0101 Lost Communication with TCM (4JJ3 with DPD)

1. DTC U0101 description

The ECM and TCM communicate the control information and diagnostic information via the CAN communication circuit. The ECM monitors the CAN operational status by expecting a constant message flow from each module. If the ECM fails to receive an expected message, the DTC is set.

2. Condition for setting DTC U0101

Condition for running the DTC

The battery voltage is 9 V or more.
3 seconds or more have passed since the ignition switch was turned ON.
DTC U0001 is not set.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC U0001 High Speed CAN Communication Bus".

Condition for setting the DTC

The ECM detects that CAN messages from the TCM are not received for 3 seconds or more.

3. Action taken when DTC U0101 sets

The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC type definitions".

The ECM limits the fuel injection quantity.
The ECM inhibits the cruise control.

4. Condition for clearing DTC U0101

Refer to Conditions for clearing the MIL/DTC - Type A or Type B.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC type definitions".