P2030 is set when the powertrain control module detects a performance problem with the vehicle's fuel-fired heater (also called an auxiliary or parking heater). The heater is not producing the expected temperature rise, is not completing its self-check, or is otherwise failing to operate as commanded during its run cycle.
The heater relies on a flame sensor to confirm combustion; a weak or contaminated sensor causes the unit to shut down or run below output, which the PCM flags as a performance fault.
If the sensor that reports heater coolant temperature to the PCM is skewed or open, the module cannot verify that the heater is actually producing heat and will set the code.
A clogged fuel line, weak lift pump, air leak, or empty fuel level can starve the heater so it cannot sustain combustion, triggering a performance fault.
Corroded pins, broken wires, or a failed heater relay can prevent the unit from running on command or intermittently, which the PCM interprets as a performance issue.
Soot buildup, a failed glow plug or igniter, or a worn combustion chamber can prevent the unit from reaching proper operating temperature.
Uncommon, but possible if the module that drives or monitors the heater has an internal failure. This should only be considered after every other cause has been ruled out.
The vehicle will usually run normally, but clearing the code without fixing the underlying issue will cause it to return, and you will lose the cold-start assistance and auxiliary cabin heating the fuel-fired heater provides.
In most cases yes. The fuel-fired heater is an auxiliary system, so the engine and main heater will still operate. The main downsides are longer cold-start warm-up time, reduced cold-start emissions performance, and no auxiliary heat when parked.
No. The PCM is one of the least likely causes of P2030. The flame sensor, coolant temperature sensor, fuel supply, wiring, and the heater unit itself should all be checked first. Replacing or reprogramming the PCM before ruling those out is a common and usually unnecessary expense.
Fuel-fired heaters are most common on diesel vehicles and on vehicles sold in cold climates, so the code shows up more often in those applications. Heavy use of the heater in very cold conditions also increases wear on its internal components.