Error code

OBD2 P0702

OBD2P0702
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Transmission Control System Electrical.

Severity

moderateCan drive, but transmission may malfunction; immediate diagnosis recommended.

Summary

P0702 indicates an electrical fault in the transmission control system, typically involving communication issues between the Engine Control Module (ECM) and Transmission Control Module (TCM).

Symptoms

  • Automatic transmission may drop gears or only run in certain gears
  • Difficulty starting, rough idle quality, or stalling when coming to a stop

Common Causes

  • Wiring damage or corrosion leading to open circuits or short circuits
  • Corrosion or water entry at connectors between ECM and TCM
  • Internal failure of the Transmission Control Module (TCM)

Diagnosis

  1. Check wiring harness between ECM and TCM for damage
  2. Inspect connectors at ECM and TCM for bent pins or corrosion
  3. Consider internal TCM failure if no external issues found

Fixes

  • Repair damaged wiring or replace faulty connectors
  • Replace the Transmission Control Module (TCM) if it is faulty

FAQ

What should I do if my car has P0702?

Check for wiring issues and connectors between ECM and TCM. If no external faults are found, consider replacing the TCM.

Is it safe to drive with P0702?

It is generally drivable but may experience transmission malfunctions; immediate diagnosis and repair are recommended.

View source

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

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