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1998 TOYOTA TACOMA
2.7L I4•RWD•AUTOMATIC•gas
5 active safety recalls on this vehicle — view recalls
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Repairs0Labor1040Torque1596Fluid17DTC3336Battery2Maintenance0Recalls5
P0683moderate severityPowertrain

Glow Plug Control Module to PCM Communication Circuit

on 1998 Toyota Tacoma 2.7L I4 · RWD

What this code means

The PCM has detected a communication fault between itself and the glow plug control module. This affects proper diesel cold-start glow plug operation.

Symptoms

  • Hard cold starts
  • Glow plug warning light on
  • Rough idle when cold

Common causes

  • Faulty wiring between PCM and glow plug module
  • Corroded connectors
  • Failed glow plug control module
  • PCM fault

Diagnostic steps

  1. Scan for glow plug related codes
  2. Inspect wiring between PCM and module
  3. Check connector integrity and grounds
  4. Test glow plug control module
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