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1994-2007 DODGE RAM 2500
5.9L I6 Cummins Diesel•4WD•AUTOMATIC•diesel•turbo
22 active safety recalls on this vehicle — view recalls🏆Sponsored by Timmehster
Repairs485Labor512Torque3106Fluid10DTC1718Battery1Maintenance0Recalls22
P0800moderate severityPowertrain

Transmission Control System (MIL Request)

on 1994-2007 Dodge Ram 2500 5.9L I6 Cummins Diesel · 4WD

What this code means

The transmission control module has detected a fault and is requesting the malfunction indicator lamp be illuminated. This is a general communication code indicating the TCM wants to alert the driver to a transmission issue.

Symptoms

  • Check engine light on
  • Transmission warning light
  • Possible shifting problems

Common causes

  • Faulty transmission control module
  • Wiring or connector fault between TCM and PCM
  • Stored transmission fault triggering MIL request
  • Poor ground connection

Diagnostic steps

  1. Scan for all stored transmission codes
  2. Address any accompanying transmission DTCs first
  3. Inspect TCM-to-PCM wiring and connectors
  4. Verify module grounds and power supply
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