P0337 Code Meaning and Next Steps

First checks take 10 to 20 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine stalls, cranks without starting, or cuts out repeatedly.
!The tachometer drops out or the warning light flashes while driving.

If the light is steady and the vehicle still drives normally: Maybe, but only for a very short distance if the engine still runs smoothly.

What to check first

Step-by-step checks

1
Free - no tools
Inspect the connector and harness for rubbing, corrosion, or a poor pin fit
2
Free - no tools
Check whether the fault happens more when hot or under vibration
3
Basic tool needed
If scan data is available, confirm whether RPM is present but unstable while cranking or running
4
Basic tool needed
Look for recent engine or transmission work that may have affected sensor routing or clearance
5
Basic tool needed
If the signal is weak only in one operating condition, that clue matters more than the code alone

If the code returns

-If the signal remains weak with a known-good harness, the sensor or trigger side becomes more likely.
-If the code returns after a repair, verify the sensor gap and harness routing again.
-If the engine starts cleanly after a fix, clear and retest before moving on.

Background

What this code means

P0337 is a generic OBD-II crankshaft-speed or engine-speed input code for crankshaft position sensor A.

A low crank signal can come from a weak sensor output, wiring fault, or trigger problem that keeps the ECU from seeing the pulse clearly.

A hard start, stall, or intermittent cut-out can happen if the crank signal falls too low to trust.

Diagnosis

Common causes

Most common

Weak crank sensor

The ECU may not be seeing a strong enough pulse.

Common

Connector or wiring issue

A poor connection can drag the signal down.

Common

Trigger wheel problem

A damaged tone ring or reluctor can reduce the signal strength.

Possible

Heat-related sensor failure

Some sensors weaken when hot.

Avoid these mistakes

What not to do

xDo not keep cranking a no-start engine for a long time if the speed signal is missing.
xDo not replace the ECU before checking the crank sensor, connector, and wiring.

Parts

Parts that may need replacing

PartTypical costNotes

Crankshaft position sensor$40-$180Relevant when the sensor is actually weak or biased low.

Connector pigtail repair$15-$90Worth checking if the connector is damaged.

Trigger wheel or reluctor repair$100-$600Relevant if the mechanical input side is damaged.

Related OBD codes

P0335

P0335 usually means the crankshaft position sensor A circuit is not behaving correctly.

P0336

P0336 usually means the crankshaft position sensor A signal is out of normal range or performance.

P0338

P0338 usually means the crankshaft position sensor A signal is reading too high.

P0339

P0339 usually means the crankshaft position sensor A signal is intermittent.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0337 was expanded around common low crankshaft-position sensor faults, including weak sensor output, connector issues, and trigger-wheel problems.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0337 - P0337 Usually Means the Crankshaft Position Sensor a Signal Is Reading Too Low