Engine-Codes - Generic - P0866

P0866 Code - TCM Communication Circuit High

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3
Table of contents

|P0866 code possible causes

  • Faulty Transmission Control Module (TCM)
  • Transmission Control Module (TCM) harness is open or shorted
  • Transmission Control Module (TCM) circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

|How is the P0866 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

|What is the cost to diagnose the P0866 code

Labor: 1.0

The cost to diagnose the P0866 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|What are P0866 code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|What is P0866 code meaning?

The Engine Control Module (ECM) monitors the Transmission Control Module (TCM). The ECM sets the OBDII when there is a problem communicating with the TCM.

|Need more information with the P0866 code?

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|P0866 code information for specific makes

|Need help with a P0866 code?

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