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.
- The ignition switch is ON.
Condition for setting the DTC
- The ECM detects that the CAN messages from the TCM are not being received.
3. Action taken when DTC U0101 sets
- Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A (Euro4).
- Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type A (Except Euro4).
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".
- The ECM limits the fuel injection quantity.
- The ECM limits the fuel rail pressure.
- The ECM inhibits the cruise control.
4. Condition for clearing DTC U0101
- Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
- Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".