What is the difference between P0335 and P0336?

P0335 means the crankshaft signal is missing or unrecognisable, so the engine generally will not start or will cut out completely. P0336 means the signal is there but its pattern is wrong — irregular spacing, a missing tooth where there should not be one, or a drift out of step with the camshaft. P0335 tends to point at the sensor and its wiring; P0336 tends to point at something physical, such as a damaged tone ring, a wrong air gap or a stretched timing chain.

Can a stretched timing chain cause P0336?

Yes, and it is the cause you cannot afford to overlook. The control unit checks that the crankshaft and camshaft signals stay in a fixed relationship. A chain that has stretched lets the camshaft fall progressively behind, and once the drift exceeds the allowed tolerance the correlation check fails. If P0336 appears alongside a camshaft correlation code, or the engine rattles for a second or two on a cold start, treat the chain as the prime suspect rather than the sensor.

Will P0336 fail an MOT?

Yes. The engine management lamp is a major defect for petrol cars first used from 1 July 2003 and diesels from 1 July 2008, and 371,859 failures have been recorded against it. There is an emissions risk too, because irregular timing means incomplete combustion, which raises hydrocarbon readings on a petrol car and smoke on a diesel.

How does a garage test a crankshaft sensor signal?

With an oscilloscope, which draws the sensor's output as a waveform rather than a number. A healthy signal is a regular series of evenly spaced pulses with one clear gap per revolution where teeth have been deliberately left out. A chipped or bent tooth shows up as an irregularity in that pattern, a wrong air gap shows as pulses that are too small, and interference shows as noise on the trace. It is far more informative than a resistance check and it is worth asking whether the garage has one.

Powertrain code · standard

P0336Crankshaft position signal is present but wrong

Standard definition: Crankshaft Position Sensor "A" Circuit Range/Performance

Last updated 27 July 2026

Quick answer

The engine control unit is receiving a crankshaft signal, but the pattern is not what it expects. Unlike P0335 the signal has not disappeared, so the engine often runs — badly, unpredictably, and with the fault getting worse.

How the car works this out

The control unit does more than count pulses. It checks that the number of teeth per revolution is right, that the missing-tooth gap appears where it should, that the pulses are evenly spaced, and that the crank signal keeps step with the camshaft signal. P0336 is set when the pulse train is present but fails one of those checks — teeth missing where there should be none, extra pulses, uneven spacing, or a drift out of step with the cam. It usually points at something physical rather than electrical.

What you might notice

Misfiring, particularly under load or at higher revs
Intermittent stalling, often followed by an immediate restart
A rev counter that flickers or jumps
Long cranking before the engine catches
Hesitation and uneven power delivery
A rattle or knock from the front of the engine if a timing chain is involved

What causes it

Most likely first. A code names the check that failed, not the part that failed it, so more than one of these can produce the same number.

1A damaged tone or reluctor ring with a chipped, bent or missing toothCommon
How to check: A garage can capture the sensor waveform on an oscilloscope. A damaged tooth appears as an obvious irregularity in an otherwise even pattern and is unmistakable.
2An incorrect air gap between the sensor and the ring, from a sensor not fully seated or the wrong part fittedCommon
How to check: Check the sensor is fully home against its shoulder and that the part number matches. A sensor sitting a millimetre proud gives exactly this code.
3Debris or metal particles on the sensor tip distorting the signalPossible
4A stretched timing chain or a worn belt letting the crank and cam signals drift out of correlationPossible
How to check: Check for a camshaft correlation code stored alongside, and listen for a chain rattle on start-up. This is the cause that must not be missed.
5A cracked flexplate or a loose crankshaft pulley on engines where the ring is part of one of thosePossible
6Electrical interference from a poorly installed aftermarket accessory or a badly routed ignition leadLess common

What to do about it

1Ask for the crank signal to be looked at on an oscilloscope. This is one of the few codes where a waveform capture settles the diagnosis outright, and guessing without one is expensive.
2Check for a camshaft correlation code at the same time. If the crank and cam are drifting apart, the timing chain or belt is the issue and that needs addressing before anything else.
3Inspect the sensor mounting and the air gap. A sensor not seated fully, or a slightly wrong replacement part, is a common and easily missed cause.
4Listen for a chain rattle from cold on an engine with a chain-driven camshaft. A stretched chain that has started to skip teeth is a serious mechanical problem, not a sensor problem.
5Do not simply clear the code and carry on if a timing component is suspected. On an interference engine a chain or belt that jumps far enough will bend valves.

Can you keep driving?

Only to a garage

The engine usually still runs, which makes this code easier to ignore than P0335 and in some ways more dangerous. If the underlying cause is a stretched timing chain, continuing to drive risks it skipping teeth, and on most modern engines that means the pistons meeting the valves. Get the cause identified before deciding how far to drive it.

Will it fail an MOT?

The lamp alone is a major defect, one of 371,859 recorded failures. The emissions risk is real too: irregular crank timing means irregular ignition and injection timing, which produces incomplete combustion, so hydrocarbon readings rise on a petrol car and smoke increases on a diesel. A car with an intermittent misfire may also stall during the emissions test, and an emissions test that cannot be completed is a major failure of its own.

The light this turns on

Engine management lightThe engine management system has found a fault it cannot correct and has stored a code for it. The car will usually still drive, but an illuminated engine light is an automatic MOT failure on petrol cars first used from 1 July 2003 and diesels from 1 July 2008.

Common questions

What is the difference between P0335 and P0336?: P0335 means the crankshaft signal is missing or unrecognisable, so the engine generally will not start or will cut out completely. P0336 means the signal is there but its pattern is wrong — irregular spacing, a missing tooth where there should not be one, or a drift out of step with the camshaft. P0335 tends to point at the sensor and its wiring; P0336 tends to point at something physical, such as a damaged tone ring, a wrong air gap or a stretched timing chain.
Can a stretched timing chain cause P0336?: Yes, and it is the cause you cannot afford to overlook. The control unit checks that the crankshaft and camshaft signals stay in a fixed relationship. A chain that has stretched lets the camshaft fall progressively behind, and once the drift exceeds the allowed tolerance the correlation check fails. If P0336 appears alongside a camshaft correlation code, or the engine rattles for a second or two on a cold start, treat the chain as the prime suspect rather than the sensor.
Will P0336 fail an MOT?: Yes. The engine management lamp is a major defect for petrol cars first used from 1 July 2003 and diesels from 1 July 2008, and 371,859 failures have been recorded against it. There is an emissions risk too, because irregular timing means incomplete combustion, which raises hydrocarbon readings on a petrol car and smoke on a diesel.
How does a garage test a crankshaft sensor signal?: With an oscilloscope, which draws the sensor's output as a waveform rather than a number. A healthy signal is a regular series of evenly spaced pulses with one clear gap per revolution where teeth have been deliberately left out. A chipped or bent tooth shows up as an irregularity in that pattern, a wrong air gap shows as pulses that are too small, and interference shows as noise on the trace. It is far more informative than a resistance check and it is worth asking whether the garage has one.

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