P0A0F: Engine failed to start
In a hybrid, the system asked the petrol engine to start and it did not fire up. Lack of fuel, ignition problems or a sensor are typical causes.
| Code | P0A0F |
|---|---|
| System | Engine and transmission |
| Group | P0Axx, Hybrid and electric |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0A0F means
In hybrids, the combustion engine starts and stops by itself as needed, turned over by the electric motor. If the system spins it and it does not start within the expected time, it stores this code. The car may carry on for a while on electric power, but without the engine the battery will eventually run down.
Most common causes
- Empty or nearly empty tank (the gauge can be misleading)
- Faulty fuel pump, relay or fuse
- Worn spark plugs, ignition coils or faulty injectors
- Faulty crankshaft or camshaft position sensor
- Immobiliser not recognising the key
- Mechanical problem, such as low compression or timing out of place
Symptoms
- Engine warning light and hybrid system warning on
- The combustion engine does not start when it should
- Limited power and hybrid battery running down
- The car may stop after a while on electric power
Can you drive with P0A0F?
With care You can move with care, but on battery alone the car will eventually stop. Head straight to a garage, or to a fuel station if the tank is low.
Open the bonnetthe in-depth explanation
How to check it
First, add fuel even if the gauge shows some left. With the reader, watch whether engine rpm appears while it tries to start, and check fuel trims: no rpm signal points to the crankshaft sensor.
How to read and clear P0A0F with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0A0F with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P0A0B The high voltage system interlock gives readings outside the normal range
- P0A0C The high voltage system interlock gives a lower signal than normal
- P0A0D The high voltage system interlock gives a higher signal than normal
- P0A0E The high voltage system interlock fails now and then
- P0A10 The DC converter state gives a higher signal than normal
- P0A11 The DC converter enabling has a broken or disconnected wire
- P0A12 The DC converter enabling gives a lower signal than normal
- P0A13 The DC converter enabling gives a higher signal than normal
- P0A1F Battery energy control module fault
- P0A7F Hybrid battery pack deterioration
- P0A80 Replace hybrid battery pack
- P0A94 DC/DC converter performance
What does code P0A0F mean?
In hybrids, the combustion engine starts and stops by itself as needed, turned over by the electric motor. If the system spins it and it does not start within the expected time, it stores this code. The car may carry on for a while on electric power, but without the engine the battery will eventually run down.
Can you drive with P0A0F?
You can move with care, but on battery alone the car will eventually stop. Head straight to a garage, or to a fuel station if the tank is low.
How do you clear P0A0F?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0A0F comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
