OBD Codes

P2029

Fuel Fired Heater Disabled

Lowcooling

Overview

The P2029 diagnostic trouble code indicates a fuel fired heater disabled condition. This code relates to the engine cooling system or air conditioning system. Cooling system problems can lead to overheating and serious engine damage if not addressed in a timely manner.

Symptoms

  • Check Engine Light (MIL) illuminated
  • Engine overheating warning
  • White smoke from exhaust (coolant burning)
  • Coolant loss without visible leak

Common Causes

  • Head gasket leak allowing coolant loss
  • Malfunctioning cooling fan or relay
  • Low coolant level from a leak
  • Failed thermostat (stuck open or closed)

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check coolant level and inspect for visible leaks
  3. 3Test the thermostat by monitoring coolant temperature during warm-up
  4. 4Inspect the coolant temperature sensor and its wiring
  5. 5Test the cooling fan operation by running the AC or using a scan tool

Estimated Repair Cost

$100$800

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Audi Q5Honda OdysseyJeep Grand CherokeeToyota Highlander

Related Codes

More Cooling Codes

Frequently Asked Questions

If your engine is overheating, stop driving immediately to prevent catastrophic engine damage. If the code is related to a sensor or thermostat and the temperature is stable, drive cautiously to a repair shop.