OBD-II Code P0335 — What It Means & How to Fix It

What Does This Error Mean?

P0335 means the engine computer is not receiving a signal from the crankshaft position sensor (CKP). This sensor tells the ECM exactly where the crankshaft is in its rotation at all times. Without this signal, the ECM cannot determine the correct timing for ignition and fuel injection. The engine will crank but may not start, or will stall while driving. This is a critical code — the vehicle may be undrivable until repaired.

Affected Models

All vehicles 1996+
Common in Ford F-150
Common in Chevrolet Silverado
Common in Dodge/Ram trucks
Common in Nissan vehicles

Common Causes

Failed crankshaft position sensor no longer generating a signal
Damaged or broken wiring between the CKP sensor and the ECM
Damaged tone wheel (reluctor ring) on the crankshaft with missing or damaged teeth
Metal debris from engine wear contaminating and disabling the magnetic sensor
Loose or corroded CKP sensor connector causing signal loss

How to Fix It

Do not attempt to drive the vehicle if the engine stalls or will not start reliably. P0335 can cause sudden engine shutdown while driving, which is a serious safety hazard. Have it towed to a shop or your driveway for diagnosis.

If the engine starts and runs but the check engine light is on, you may be able to drive carefully to a nearby shop. But avoid highway speeds until the repair is complete.
Locate the crankshaft position sensor. It is usually found on the engine block near the crankshaft pulley (front bottom of engine) or near the flywheel/flexplate (rear of engine, near the transmission). It is a small sensor with a 2-3 wire connector.

Consult a repair guide for your specific vehicle — the CKP sensor location varies significantly between makes and models. Some require lifting the vehicle to access.
Inspect the connector and wiring going to the sensor. Unplug the connector and look for corrosion, bent pins, or broken wires. Road debris and heat can damage this harness. Repair any wiring faults before replacing the sensor.

Wiggle the wiring harness while watching for changes on a scan tool or while someone tries to start the engine. An intermittent connection often reveals itself when wires are flexed.
Test the sensor's resistance or voltage output if you have a multimeter. Most magnetic CKP sensors read 200-1,000 ohms between the signal terminals. Hall-effect sensors need key-on voltage to test. An out-of-spec reading confirms sensor failure.

If you don't have testing equipment, the most practical next step is simply replacing the sensor — it is usually the most affordable part in the system and is the most common failure point.
Replace the crankshaft position sensor. Remove the old sensor (usually one bolt), pull it out, install the new one, and reconnect the wiring. On some vehicles, a relearn procedure is required after replacement — a scan tool may be needed for this step.

Some GM and Ford vehicles require a CKP variation relearn procedure after sensor replacement. Without the relearn, the engine may still run rough or set a code. A shop can perform this quickly with the right scan tool.

When to Call a Professional

P0335 is rated critical because the vehicle may not start or may stall unexpectedly. Do not drive a vehicle with this code if it is stalling or hard to start — it is a safety risk. A crankshaft position sensor replacement typically costs $150-$350 parts and labor. If the reluctor ring (tone wheel) is damaged, repair costs can rise to $500-$1,500 depending on the repair needed. Have the vehicle towed to a shop if it will not start reliably.

Frequently Asked Questions

Why is P0335 rated as critical?

The crankshaft position sensor is essential for the engine to run. Without it, the ECM has no way to know where the pistons are in their cycle. It cannot time the spark or fuel injection correctly. This causes the engine to not start, or to stall suddenly while you are driving. A sudden stall at highway speed is a real safety hazard — hence the critical rating.

What is a reluctor ring and can it fail?

The reluctor ring (also called a tone wheel) is a toothed metal ring on the crankshaft. The CKP sensor reads the passing teeth to determine crankshaft position and speed. If a tooth is broken or the ring is damaged, the sensor gets an incomplete signal. A damaged reluctor ring requires internal engine disassembly to repair. It is much less common than a sensor or wiring failure, but it happens on high-mileage engines.

Can I replace the crankshaft position sensor myself?

Yes, on many vehicles this is a DIY repair. The sensor is usually accessible from outside the engine without major disassembly. You will need basic hand tools and possibly a lift or jack stands to access it. However, if a relearn procedure is required, you will need a compatible scan tool. If you are not comfortable working under the car, a mechanic is the safest choice.