Lack Of Communication
CAN Communications Error
The TCM receives information from the ECM via the high speed CAN network. If the CAN link or network fails, the TCM no longer has torque or engine speed information available. The TCM will store a U0073 fault code and will illuminate the MIL immediately (missing engine speed) if the CAN Bus is off. The TCM will store a U0100 fault code and will illuminate the MIL immediately (missing engine speed) if it stops receiving CAN messages from the ECM.
ECU CAN COMMUNICATION MALFUNCTIONS
| DTCs | U0073
- Control Module Communication Bus "A" Off U0074 - Control Module Communication Bus "B" Off U0101 - Lost Communication with TCM U0102 - Lost Communication with Transfer Case Control Module U0121 - Lost Communication With Anti-Lock Brake System (ABS) Control Module U0151 - Lost Communication With Restraints Control Module U0212 - Lost Communication With Steering Column Control Module U029D - Lost Communication With NOx Sensor "A" U029E - Lost Communication With NOx Sensor "B" U0307 - Software Incompatibility with Glow Plug Control Module U0407 - Invalid Data Received from Glow Control Module U059E - Invalid Data Received from NOx Sensor "A" U059F - Invalid Data Received from NOx Sensor "B" U0002 - High Speed CAN Communication Bus Performance U1013 - Invalid Internal Control Module Monitoring Data Received from TCM U010E - Lost Communication with Reductant Control Module U0140 - Lost Communication with Body Control Module U02A2 - Lost Communication with Reductant Quality Module U0155 - Lost Communication with Instrument Panel Cluster (IPC) Control |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | Not Applicable |
| Monitoring Duration | Continuous |
TYPICAL MALFUNCTION THRESHOLDS
| U0073
- CAN Chip Driver detect CAN line short or open > 10 ms U0074 - CAN Chip Driver detect CAN line short or open > 10 ms U0101 - TCM master message not received > 1 sec U0102 - TCCM master message not received > 5 sec U0121 - ABS master message not received > 5 sec U0151 - RCM master message not received > 10 sec U0212 - SCCM master message not received > 5 sec U029D - NOx Sensor "A" master message not received > 1 sec U029E - NOx Sensor "B" master message not received > 1 sec U0307 - Glow module reporting "safe glow" mode U0407 - Calibration Verification Number not received by ECU U059E - Calibration Verification Number not received by ECU U0002 - ECM transmit CAN buffer overload > 5 sec U1013 - invalid data received from TCM > 5 sec U010E - RDCM master message not received > 5 sec U0140 - BCM master message not received > 5 sec U02A2 - RDQM master message not received > 5 sec U0155 - IPC master message not received > 5 sec |
Vehicle speed is received by the ECU over CAN from the ABS system or (if the ABS system is faulted on all 4 wheel speed sensors) the TCU through Output Shaft Speed calculation to wheel speed
VS COMMUNICATION PLAUSIBILITY MALFUNCTIONS
| DTCs | P0500 Vehicle Speed Sensor "A" |
| Monitor Execution | Continuous |
| Monitor Execution | None |
| Sensors OK | Not Applicable |
| Monitoring Duration | Continuous |
TYPICAL MALFUNCTION THRESHOLDS
| VS signal is missing from the CAN system for 0.5 Seconds. |