Error code

OBD2 P0864

OBD2P0864
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

TCM Communication Circuit Range/Performance.

Severity

moderateCan drive, but shifting may be affected and the vehicle could enter 'limp mode'.

Summary

P0864 indicates a problem with communication between the transmission control module (TCM) and other modules in the vehicle's network.

Symptoms

  • Transmission shifts poorly
  • Stuck in 'limp mode'
  • Illuminated check engine light

Common Causes

  • Problem with TCM
  • Faulty wiring or poor connection to TCM
  • CAN bus issues

Diagnosis

  1. Clear code and check if it returns
  2. Inspect TCM connector for physical damage or poor connections
  3. Verify TCM is inactive on network using a scan tool
  4. Check power supply to TCM
  5. Test data communication lines

Fixes

  • Replace faulty wiring, connectors, or the TCM itself

FAQ

What should I do if clearing the code doesn't solve P0864?

Inspect the TCM and its connections for any physical damage or poor connections. If issues persist, consult a professional mechanic.

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.