OBD-II trouble code
P0335: Crankshaft Position Sensor "A" Circuit
The engine computer isn't getting a usable signal from the crankshaft position sensor. The engine may not start, may stall while driving, or may run intermittently — the crank sensor is critical for ignition and fuel injection timing.
Quick facts
- System
- Powertrain
- Category
- Sensors / Timing
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $150 – $400
- DIY difficulty
- Intermediate DIY
Browse every code in P0300–P0394, or start from the full code library.
What does P0335 mean?
The crankshaft position sensor reports the rotational position and speed of the crankshaft to the engine control module (ECM). The ECM uses this signal to determine ignition timing, fuel injection timing, and engine speed. Without a reliable crank signal, the engine cannot operate properly — and on many vehicles, it cannot start at all.
P0335 is set when the ECM detects a fault in the crankshaft position sensor circuit — either no signal, an erratic signal, or a signal that doesn't match what the engine speed should produce. The crank sensor is one of the most critical inputs to the engine management system, and a fault here is almost always serious.
The most common cause is a failed crankshaft position sensor itself — crank sensors are exposed to heat, vibration, and oil contamination, and they have a finite service life — but a connector or wiring fault produces an identical no-signal result and costs nothing to eliminate first. After the sensor itself, the next likely causes are damaged or chafed sensor wiring, a corroded or loose connector, or a damaged tone ring (the toothed reluctor wheel on the crankshaft that the sensor reads). A blown fuse can also cut off sensor power. P0335 is one of the few OBD codes where the car may genuinely refuse to start.
Common causes
- Corroded or loose sensor connector
- Damaged or chafed sensor wiring
- Blown fuse on the crank sensor circuit
- Failed crankshaft position sensor, the common answer once the connector, wiring and supply are clear, and more likely past 100,000 miles
- Excessive metal debris on the sensor face (from clutch or bearing wear)
- Damaged tone ring or reluctor wheel on the crankshaft
- Faulty ECM input circuit (rare)
Symptoms
- Check engine light is on
- No-start condition — engine cranks but won't fire
- Intermittent stalling while driving
- Engine quits after warming up and restarts when cool (heat-soaked sensor)
- Long crank times before the engine fires
- Erratic tachometer behavior
- Possible no spark and no fuel injection during cranking
Diagnostic steps
- 1.Inspect the crank sensor connector for damage, corrosion, or loose pins. A loose or corroded connector produces the same no-signal result as a dead sensor and is free to rule out.
- 2.Visually inspect the wiring between the sensor and the engine harness for chafing, breaks, or rodent damage.
- 3.Check the crank sensor circuit fuse and replace if blown.
- 4.With the engine cranking, use a scan tool to monitor RPM. A consistent reading of 0 RPM during cranking confirms the sensor is not producing a signal. Before anyone turns the key, get hands, leads and loose clothing clear of the belt and the fan, and have the person cranking sit in the vehicle rather than reach through the engine bay.
- 5.Test sensor resistance against the manufacturer's specification, but establish which type is fitted first. A two-wire inductive (variable reluctance) sensor has a winding and reads a real resistance, typically from the low hundreds of ohms up to about 1,200. A three-wire Hall-effect sensor has no winding to measure and cannot be ohm-tested at all — on those, confirm supply and ground at the connector with the ignition on, then watch the signal while cranking.
- 6.Inspect the tone ring on the crankshaft for damaged or missing teeth — possible after clutch or flywheel work.
- 7.Replace the crankshaft position sensor if wiring, connector, and power tests pass.
Repair cost
$150 – $400
Crankshaft position sensor replacement is $150 to $400 in parts and labor on most vehicles. The sensor itself is $30 to $150. Labor varies based on sensor location — some sensors are accessible from above, others require getting under the vehicle or removing other components. Tone ring damage requires more extensive work (transmission removal on some vehicles) and runs into the thousands.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with crankshaft position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.