OBD Guide

P0865

TCM Communication Circuit Low

P0865 is an OBD-II diagnostic trouble code meaning: TCM Communication Circuit Low. Common causes: open or short circuit in the tcm communication circuit, bad contacts in connectors. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Incorrect gear shifting
  • Transmission transition to emergency mode
  • Check Engine Light Illuminates
  • Reduced engine power
  • Problems with cruise control

Causes

  • Open or short circuit in the TCM communication circuit
  • Bad contacts in connectors
  • TCM module malfunction
  • Problems with power supply or grounding of the TCM module
  • Malfunction of other related modules (e.g. engine ECU)

How to Fix

  1. Check the integrity of the TCM communication circuit
  2. Inspect and clean the contacts in the connectors
  3. Check the power supply and grounding of the TCM module
  4. Scan other modules for errors
  5. If necessary, replace the TCM module

Related codes

Error P0865 by Vehicle Brand

FAQ

What does the P0865 code mean?

P0865 is an OBD-II diagnostic trouble code that indicates: TCM Communication Circuit Low

What causes a P0865 error code?

The most common causes of P0865 include: Open or short circuit in the TCM communication circuit; Bad contacts in connectors; TCM module malfunction; Problems with power supply or grounding of the TCM module.

How do I fix a P0865 diagnostic trouble code?

To fix P0865: Check the integrity of the TCM communication circuit. Inspect and clean the contacts in the connectors. Check the power supply and grounding of the TCM module. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0865?

Limited driving only, diagnose soon

How much does it cost to fix P0865?

The estimated repair cost for P0865 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat