OBD-II Code P0337 — What It Means & How to Fix It

What Does This Error Mean?

P0337 means the crankshaft position sensor circuit on Bank 1 is reading a signal that is too low. The crankshaft position sensor is one of the most critical sensors in your car — the ECM uses it to know where the pistons are and how fast the engine is spinning. A low signal means the ECM is getting bad data, which can cause hard starting, stalling, or rough running. This code needs prompt attention — a completely failed crank sensor can leave you stranded.

Affected Models

All vehicles 1996+
Common in GM vehicles (Chevrolet, GMC, Buick, Cadillac)
Common in Ford and Lincoln vehicles
Common in Chrysler, Dodge, and Jeep vehicles
Common in Honda and Acura vehicles

Common Causes

Failing crankshaft position sensor producing a weak output signal
Damaged or corroded wiring to the crankshaft position sensor on Bank 1
Excessive gap between the sensor and the reluctor ring on the crankshaft
Damaged reluctor ring (tone wheel) with missing or chipped teeth
Weak power or ground supply to the crankshaft position sensor

How to Fix It

Confirm the code and check for companion codes with an OBD-II scanner. P0335 (circuit malfunction) or P0336 (range/performance) alongside P0337 suggests the sensor signal has multiple problems. P0300-series misfire codes confirm the bad signal is causing ignition timing issues.

Freeze frame data showing the RPM when the code set is useful — a low signal at idle versus highway speed points to different causes.
Locate the crankshaft position sensor. It is typically mounted to the engine block near the crankshaft pulley (front) or near the transmission bell housing (rear). Inspect the connector for corrosion, loose pins, or damaged wiring. Clean and reseat the connector.

A corroded or loose connector is a very common and easy fix for a low signal code.
Check the sensor's air gap — the distance between the sensor tip and the reluctor ring on the crankshaft. If the sensor has shifted or the mounting bracket is bent, the gap may be too large for the sensor to generate an adequate signal. The typical gap is 0.020-0.060 inches.

An excessive air gap is particularly common after engine or timing work where the sensor was removed and not reinstalled correctly.
Inspect the reluctor ring on the crankshaft for missing teeth, cracks, or debris. A chipped or broken tooth causes a brief signal dropout each revolution — this can trigger low voltage codes or range/performance codes.

This requires getting a good look at the ring with a flashlight from underneath the vehicle.
Test the crankshaft position sensor with a multimeter. Depending on whether it is a magnetic (2-wire) or Hall effect (3-wire) sensor, testing procedure differs. Consult your service manual for the correct test procedure and pass/fail values. If the sensor fails, replace it.

Magnetic crankshaft sensors typically read 200-2,000 ohms. Hall effect sensors need to be tested for power, ground, and output signal.

When to Call a Professional

The crankshaft position sensor is relatively accessible on many engines but can be awkward on others. If you're not comfortable working underneath the vehicle, a mechanic can replace this sensor in 30-60 minutes on most engines. Don't delay — a deteriorating crankshaft position sensor can fail completely and leave the car unable to start. Expect $150-$300 for crankshaft position sensor replacement installed.

Frequently Asked Questions

Can a bad crankshaft position sensor cause a no-start?

Yes — and it's one of the most common causes of a no-start with no obvious reason. The ECM must have a reliable crankshaft position signal to fire the spark plugs and injectors. With no signal or a very low signal, the ECM doesn't know when to fire anything, and the engine won't start. If your car cranks normally but won't start, a failed crank sensor is high on the suspect list.

How do I know if my crankshaft position sensor is failing?

Common symptoms include: - Intermittent stalling, especially at low speed or after warmup - Hard starting after the engine is hot - Engine cranks but won't fire - Check engine light with codes P0335-P0338 - Rough running at idle Many crank sensors fail gradually, getting worse over months before complete failure.

How much does a crankshaft position sensor cost?

The sensor itself typically costs $20-$80 for a quality part. Labor varies based on how accessible the sensor is on your engine. Easy-to-reach sensors add $50-$100 for labor. Sensors in tight locations behind the engine or near the transmission can add $100-$200 in labor. Total repair is usually $100-$250.