OBD-II Fault Code

P0337: Crankshaft Position Sensor A Circuit Low Input

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0337.

System family

Powertrain

Generic/SAE

Repair category

Engine timing / position

Use this category to narrow your checks before replacing parts.

Severity

High

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What P0337 usually means

Crankshaft Position Sensor A Circuit Low Input.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault; No-start, rough running, limp mode or poor power possible

Likely causes

Faulty cam/crank sensor; Oil level/quality issue; VVT solenoid fault; Timing chain/belt issue; Wiring fault; Low signal voltage; Weak power supply; High resistance/poor ground; Failed sensor

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses; Check oil level/condition; Inspect sensor/solenoid connectors; Compare cam/crank correlation with scan data; Check sensor reference voltage, ground and signal voltage

Repair guidance

Repair wiring or replace confirmed failed sensor/solenoid; Investigate mechanical timing if correlation faults remain; Repair poor ground/power feed or replace confirmed faulty sensor

Verification after repair

Clear code, road-test through the same drive condition, then rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary. A DTC identifies a circuit or system condition, not always the failed part.