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P0338: Crankshaft position sensor A circuit high input

The ECU sees a crankshaft sensor signal above normal. Usually a wire carrying voltage where it should not, the connector or the sensor itself.

Code P0338 at a glance
CodeP0338
SystemEngine and transmission
GroupP03xx, Ignition and misfires
TypeGeneric: it means the same on every make
Can you keep driving?With care

What P0338 means

The crankshaft sensor reads a toothed wheel that turns with the engine and tells the ECU how fast it is spinning and where the pistons are. It is one of the most important signals: without it the engine cannot time fuel or spark. High input means the ECU is reading a voltage above what is possible, almost always from an electrical problem. Which sensor is "A" is up to each manufacturer; many cars only have one.

Most common causes

  • Moisture or corrosion in the connector
  • Signal wire touching another live wire
  • Sensor earth wire broken or poorly connected
  • Failed sensor
  • ECU fault (rare)

Symptoms

  • Hard starting or no start
  • Engine cuts out suddenly
  • Jerking under acceleration
  • Engine warning light on

Can you drive with P0338?

With care If the engine still runs you can drive carefully, but it could cut out on the move. Get it to a garage as soon as possible.

How to check it

Inspect the sensor connector: if it is damp or green inside, clean and dry it, clear the code and see whether it returns.

How to read and clear P0338 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 P0338 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

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 the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

P0338 is a generic code, so it means the same on any make, for example on Audi, Fiat, Mazda, Opel / Vauxhall, Peugeot, Toyota. See what Final OBD does on your car in makes and models.

What does code P0338 mean?

The crankshaft sensor reads a toothed wheel that turns with the engine and tells the ECU how fast it is spinning and where the pistons are. It is one of the most important signals: without it the engine cannot time fuel or spark. High input means the ECU is reading a voltage above what is possible, almost always from an electrical problem. Which sensor is "A" is up to each manufacturer; many cars only have one.

Can you drive with P0338?

If the engine still runs you can drive carefully, but it could cut out on the move. Get it to a garage as soon as possible.

How do you clear P0338?

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, P0338 comes back.