• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The transmission control module (TCM) sends vehicle speed data to the engine control module (ECM). The data is sent to the ECM through a high speed network called the GM control area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P0864 to set by itself. If a CAN fault occurs, other DTCs set before DTC P0864.
• | The ignition is ON for more than 3 seconds. |
• | The ignition voltage is between 10-18 volts. |
• | No other CAN errors are present. |
• | DTC P0864 runs continuously once the above conditions are met. |
The ECM receives no valid vehicle speed data from the TCM for more than 1 second.
DTC P0864 is a type A DTC.
DTC P0864 is a type A DTC.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Important: Record all Failure Records before clearing the DTC. Using Clear Info erases the Failure Records from the engine control module (ECM) and transmission control module (TCM).
⇒ | If any TCM Freeze Frame/Failure Records are recorded refer to Diagnostic Trouble Code (DTC) List - Vehicle . |
⇒ | If DTC P0864 sets and no TCM DTCs are present, replace the ECM. |
⇒ | If DTC P0864 and TCM DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming