How serious is this DTC?
A stored P2029 code will likely be accompanied by a lack of heat in the cabin. The stored code indicates that an electrical issue or a serious mechanical failure has occurred. In very cold weather, the conditions that led to the storage of such a code must be corrected as quickly as possible.
What are some of the symptoms of the code?
Symptoms of a P2029 fault code may include:
- No heat in the cabin
- Excessive heat in the cabin
- The air conditioning fan may be temporarily disabled
- No symptoms may appear
- What are some common causes of the code?
Causes
of this code may include:
- Faulty temperature sensor (air or coolant)
- Faulty fuel heater injector
- Faulty fuel heater burner/igniter
- Shorted or open wiring or connectors in the fuel heater circuit
- Faulty PCM or programming error
What are the troubleshooting steps for P2029?
A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle-specific diagnostic information will be needed to diagnose a P2029 code.
You can use your vehicle information source to locate a technical service bulletin (TSB) that matches the vehicle’s year, make, and model; as well as the engine size, stored codes, and symptoms presented. If you find one, it may provide useful diagnostic information.
Use the scanner (connected to the vehicle’s diagnostic connector) to retrieve all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, then test the vehicle until the PCM enters readiness mode or the code resets.
If the PCM enters readiness mode at this point, the code is intermittent and may be much harder to diagnose. If this is the case, the conditions that led to the code being stored may need to worsen before an accurate diagnosis can be made.
If the code is immediately reset, the next step in your diagnosis will require you to search your vehicle information source for diagnostic flowcharts, connector pinout diagrams, connector face views, and component testing procedures/specifications.
If the fuel heater has been disabled, the code may need to be cleared immediately before testing.
Step 1
Use the DVOM to test the temperature sensors (air or coolant) according to the manufacturer’s specifications. Sensors that do not test within the allowed parameters should be considered faulty.
Step 2
Use your vehicle diagnostic information source and the DVOM to test the fuel heater injectors and igniters with the system activated. If weather conditions do not allow activation, use the scanner to activate it manually.
Step 3
If the system switches and other components are functional, use the DVOM to test the input and output signal circuits of the fuse panel, PCM, and ignition switch. Disconnect all controllers before using the DVOM for testing.
Fuel heater systems are mainly used in diesel engine vehicles and in extremely cold markets