Symptoms of a Bad Crankshaft Position Sensor: What Reports Show

The crankshaft position sensor tells the engine computer how fast the crankshaft is turning and where it is — the timing reference the whole engine runs on. Lose it and the engine loses its heartbeat: it stalls, or it cranks and will not start, often intermittently and maddeningly. Like its twin the camshaft sensor, it is rarely named by owners — 233 of 165,897 complaints across model years 2010 to 2020 — because drivers report the stall and the shop names the part. It is a decent set to read for direction, and its story is a sharper version of the cam sensor’s.

The signature: a car that quits

Stalling defines the crank-sensor complaint: 52.4% of reports describe it, against 25.3% of the control — twice as often. The mechanism is as direct as it gets: without a reliable crankshaft signal the computer cannot time the spark and injection, so the engine simply stops. Loss of power and limp mode (20.2% against 10.5%) belong to the same failure, and nearly a third of reports — 29.2% against 17.4% — end in a tow, because a stall away from home strands you. A car that dies while driving and then restarts, with no fuel or obvious ignition cause, should put the crankshaft and camshaft sensors at the top of the list.

The no-start it’s known for

Where the crank sensor separates itself even from the cam sensor is the no-start. An intermittent no-start — the car cranks but will not fire — appears in 17.2% of crank-sensor reports against 4.7% of the control, nearly four times as often, and more than the camshaft sensor draws in its own file. The reason is mechanical: the computer will tolerate a lot, but with no crankshaft signal it does not know the engine is turning, so it withholds spark and fuel entirely and the engine never catches. The pattern is often heat-related — fine cold, dead once hot, alive again after cooling — which is why the fault so often survives a first trip to a shop where the car starts perfectly. Our guide to why a car won’t start covers the wider tree.

Its twin, and its recalls

Two associations stand out and both are practical. First, the camshaft position sensor is the crank sensor’s constant companion, named in 8.6% of crank-sensor reports against 0.2% of the control — more than forty times as often — because the two do the same kind of job at different shafts, throw related codes, and are the pair a shop tests and often replaces together. Our guide to the camshaft position sensor covers that side. Second, and more useful still: 51.5% of crank-sensor reports reference a recall or technical service bulletin, against 29.1% of the control, because a stalling engine is a safety concern that draws campaigns. RAM 1500 pickups and Dodge Journeys lead this file, so the first move is to run the VIN through the recall lookup and read the complaint history — a covered repair is a very different bill.

Crankshaft or camshaft sensor?

They are twins and hard to separate by feel, which is exactly why they are named together so often. The rough division: the crankshaft sensor leans harder toward an outright no-start, because its signal is essential for the engine to fire, while the camshaft sensor leans a little more toward running-but-rough and hesitation. But the reliable separation is the code, not the symptom: a P0335 or P0336 points at the crank sensor, a P0340 or P0341 at the cam sensor. A good diagnosis reads both and checks the wiring to each, since an intermittent “sensor” fault is frequently a chafed wire rather than the sensor itself.

What to do when you suspect it

Read the code first — a stored P0335/P0336 is worth more than any guess from an intermittent stall. Because the crank and cam sensors are cousins, consider both and inspect the wiring and connectors to them, a common real cause of an “intermittent sensor.” Given that half these reports tie to a campaign, check the recall before buying the part, especially on a RAM or Dodge. And take the heat-related pattern seriously: if a warm restart makes the fault vanish, catch the code while it is stored, because a car that starts fine on the lift teaches the shop nothing.

On a used car you are about to buy

An intermittent stall or no-start is the easiest serious fault to miss on a test drive, since the car may behave for the whole time you have it. Scan for stored and pending codes rather than trusting a car that started fine, and take any “it stalls sometimes” history seriously. Check the model and year in the complaint lookup and its open recalls — crank-sensor stalling draws both, and the RAM and Dodge concentration in this data shows how model-specific it can be.

Common questions

What are the symptoms of a bad crankshaft position sensor?

The signature is stalling — present in 52.4% of reports, twice the control — and an intermittent no-start (17.2%, nearly four times the control), because the crankshaft signal is the one the engine cannot run without. Loss of power and a tow are common too. A check-engine light appears in 44.6%; read the actual code (the P0335/P0336 family) rather than guessing.

Is it the crankshaft or camshaft position sensor?

They are twins and are named together forty times as often as chance would suggest, so read the codes rather than the feel. A P0335/P0336 points at the crank sensor, a P0340/P0341 at the cam sensor. Broadly the crank sensor leans toward an outright no-start and the cam sensor toward rough running, but a good shop tests both and checks the wiring, since intermittent faults are often a chafed wire.

Can a bad crankshaft sensor cause a car to stall?

Yes — it is the most common symptom, in 52.4% of these reports against 25.3% of other engine complaints. Without a crankshaft signal the computer can’t time the engine, so it stalls, often while driving, and nearly a third of reports end in a tow. A car that dies and restarts with no obvious cause is a strong crank-or-cam-sensor candidate.

Why does my car start when cold but not when hot?

That heat-related, intermittent no-start is a classic crank (or cam) position sensor pattern: a marginal sensor works cold and drops out as it warms, so the car cranks without firing until it cools. It appears in these reports at nearly four times the control rate. Catch the stored code while the fault is present, and have the sensor and its wiring tested rather than replaced on a guess — and check the recall first, since half these reports are tied to one.