P0644

DTC P0644, sometimes indicated as P064400 is an OBD diagnostic trouble code indicating a generic fault with the vehicle powertrain (i.e. engine and gearbox). This code identifies an error with the causing driver display serial communication circuit.

This code may be set if the PCM (Powertrain Control Module) cannot communicate with the driver display. There are many potential causes for this code, including a defective driver display, a defective PCM, or wiring issues.
If this code is set, the best way to diagnose the issue is to start by checking the wiring and connectors between the PCM and the driver display. If everything looks okay, then the next step would be to test the driver display itself. If the driver display is defective, then the PCM will need to be replaced.

• P0644: Driver Display Serial Communication Circuit
• P0644: Driver Display Serial Communication Link
• P0644: Driver display, serial communication – circuit malfunction
• P0644 00: Driver display, serial communication - circuit malfunction