P0863: TCM Communication Circuit
MediumPowertrainTransmission
What does P0863 mean?
P0863 is a diagnostic trouble code indicating "TCM Communication Circuit". This code relates to your vehicle's transmission and should be diagnosed to determine the root cause. The severity level helps indicate how urgently this should be addressed.
Symptoms you may notice
- Check engine light (MIL) illuminated on dashboard
- Intermittent warning lights
- Erratic gauge readings
Estimated repair cost
Typical range in Australia (parts + labour)
$100 – $500 AUD
Common causes
- Faulty transmission component
- Wiring or connector issue in the related circuit
- Failed sensor providing incorrect readings
- Software/calibration issue requiring ECU update
- Related component causing secondary fault
What should you do?
This code sits in a powertrain control module. The engine or transmission can drop into limp mode or cut out, which is its own hazard in traffic or on a motorway. Get it diagnosed before your next trip rather than waiting for the next service.
Get a diagnosis for YOUR car
Code P0863 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.