P2029
Fuel Fired Heater Disabled
Auxiliary emissions / cold-start heating
Generic OBD-II
Low
What it means
P2029 means the control module has disabled the fuel-fired heater — an auxiliary burner used on some vehicles to warm the coolant or cabin faster in cold weather. It's typically set because a fault or an out-of-range condition made the module shut the heater off, and it does not affect the engine's ability to start or run.
Low
Can I keep driving? Safe to drive; the engine runs normally. You may only notice slower cabin or engine warm-up in cold weather.
Common symptoms
What you'll notice
- Check-engine light on
- Slow cabin or engine warm-up in cold weather
- Auxiliary (fuel-fired) heater not operating
Common causes
Most likely first
- Fuel-fired heater has been disabled by the control module due to a fault or unmet operating conditionsLikely
- Fault in the heater's control circuit or wiringCommon
- Low fuel or conditions outside the heater's operating rangeCommon
- Faulty fuel-fired heater unitLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and any companion codes to see why the module disabled the heater.
- Confirm operating conditions (fuel level, temperature, battery voltage) are within the range the heater needs.
- Inspect the heater's wiring, connector, and fuse for faults.
- Have the fuel-fired heater unit tested per the manufacturer's procedure and replace if faulty.
FAQ
Quick answers
Is it safe to drive with P2029?+
Yes. The fuel-fired heater only assists warm-up in cold conditions, so the engine drives normally without it — you may just see slower heat and the warning light.
Can I just clear P2029?+
It will return if the module still has a reason to disable the heater. Address the companion codes or heater fault first, then clear.
Related codes
Often seen with P2029
Read & clear P2029 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX