Fuel Fired Heater Disabled
The P2029 code indicates that the powertrain control module (PCM) has detected a fault in the fuel fired heater system, typically used in diesel vehicles to preheat the engine coolant. This heater is often disabled due to an electrical issue, such as a blown fuse, faulty relay, or wiring problem. The system may also be disabled if the PCM detects a safety concern, like a fuel leak or overheating. This code is common in colder climates where the heater is essential for engine warm-up.
1. Most Common Causes
- Internal failure of the fuel fired heater control module (FHCM)
- Blocked combustion air intake or exhaust outlet on the heater
- Faulty fuel metering pump for the heater
- Defective glow plug or igniter in the heater
- Coolant or heater temperature sensor out of range
- Short, open, or corroded wiring or connectors in the heater circuit
- Low fuel level or contamination in the heater fuel supply system
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine takes longer to warm up in cold weather
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Inspect the fuel fired heater fuse and relay; replace if blown or faulty.
Step 3: Visually inspect wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test the heater unit's resistance and power supply; replace if defective.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but the vehicle may have reduced heating performance and longer warm-up times. In cold climates, this can affect comfort and engine efficiency.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on the cause. A fuse or relay replacement is cheaper, while a new heater unit can cost more.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.