P0335: the crankshaft sensor that stalls the car

A code that can stall the engine on the move and refuse to start a minute later. Where to begin, and why the part is not first.

P0335 — the unit sees no signal from the crankshaft position sensor. It is one of the few codes that can stall the engine while you are driving, so it should not be left.

Why this sensor matters so much

Its signal tells the unit where the pistons are. Without it the unit cannot work out when to spark or when to inject, and simply stops doing both. The engine dies instantly, as if the key had been turned off.

Hence the typical picture: the car stalls on the move, refuses to start for a minute, then starts and drives as if nothing happened. The sensor cools down and the signal comes back.

How it feels

• The engine stalls while driving, without warning, usually when hot.
• The starter turns briskly but the engine will not catch.
• The rev counter sits at zero or jumps during cranking.
• Misfires and jerks on the move, as if ignition vanished all at once.

If that matches, see also stalls while driving and will not start — other causes of the same behaviour are covered there.

Where to start: cheapest first

First, the connector and the wire. The sensor sits low on the engine, by the flywheel or the pulley, where it is showered with dirt, oil and road salt. A corroded contact gives exactly the same code as a dead sensor and costs nothing. Unplug it, look for green deposits and oil, and feel along the whole wire.

Second, the reluctor ring. The pulley or flywheel carries a toothed ring the sensor counts. A chipped or clogged tooth, or a pulley that shifted during a repair, makes the signal wrong. If the code appeared right after a belt or clutch job, start here.

Third, the air gap. The sensor sits at a fixed distance from the ring. A bolt not tightened fully, or a lost washer, changes that gap and weakens the signal.

And only fourth, the sensor itself. It does wear out, especially from heat, but going to it first is a reliable way to replace a good part and keep the fault.

Neighbouring codes

P0336 — there is a signal, but its shape is wrong. That points at the reluctor ring and the gap more often than at the sensor.

P0340 — the same thing for the camshaft sensor. That one lives up top, in the clean, and fails less often. If both codes arrive together, look for something shared: power, an earth, or slipped valve timing.

What not to do

Clear the code and carry on. Clearing fixes nothing, and a car that stalls on the move is dangerous: the power steering and brake servo go with the engine. If it has stalled twice already, that is a reason to drive to a garage now rather than later.

In short

• P0335 — no crankshaft position signal; the engine may stall while driving.
• Typical sign: stalls when hot, will not start for a minute, then drives on.
• Order: connector and wire → reluctor ring → air gap → sensor.
• P0336 means a wrong signal; P0340 is the same for the camshaft.
• Do not clear and drive: steering and brakes go with the engine.