Quick answer: The P0335 code indicates a malfunction in the Crankshaft Position (CKP) sensor circuit. This sensor monitors engine speed and position to time fuel injection and ignition. It is a critical fault that often prevents the engine from starting or causes stalling, requiring immediate attention to avoid being stranded.
Seeing a Check Engine Light accompanied by a P0335 code can be frustrating, especially if your car is struggling to start or stalling while driving. This code points to a communication breakdown between your engine’s brain and its internal rotation, but it is often a manageable issue once you understand the root cause.
What Does P0335 Mean?
The P0335 code stands for “Crankshaft Position Sensor ‘A’ Circuit Malfunction.” Your vehicle’s Engine Control Module (ECM) relies on the crankshaft position sensor to determine exactly where the pistons are located within the cylinders. By tracking the rotation of the crankshaft, the computer knows when to fire the spark plugs and inject fuel. When the ECM stops receiving a signal, or receives an erratic or “noisy” signal from this sensor, it triggers this code because it can no longer safely time the engine’s combustion cycle.
Symptoms
- Engine fails to start or experiences a long crank time.
- Engine stalls unexpectedly while idling or driving.
- Noticeable misfiring or rough engine performance.
- Poor fuel economy as the engine timing becomes inefficient.
- The Check Engine Light is illuminated on the dashboard.
Possible Causes
Many owners make the mistake of immediately replacing the crankshaft sensor, only to find the problem persists because the issue was actually a simple wiring fault. Always check for electrical continuity before buying new parts.
- Corroded or damaged wiring/connectors at the sensor.
- Loose or improperly installed crankshaft sensor.
- A buildup of metallic debris or dirt blocking the sensor’s magnetic pickup.
- A failed crankshaft position sensor.
- Faulty timing belt or chain causing misalignment (rare).
Check These Yourself Before Visiting a Mechanic
- Visually inspect the wiring harness leading to the sensor for any signs of fraying, heat damage, or rodent nesting.
- Ensure the sensor connector is plugged in firmly and that the locking tab is secure.
- Check your battery voltage, as a weak battery can sometimes cause erratic sensor readings in sensitive electronic systems.
How to Fix It
- Clear the code with an OBD-II scanner and test drive to see if it returns.
- Inspect and clean the sensor area, removing any oil, dirt, or metallic shavings that may interfere with the magnetic signal.
- Use a multimeter to test the wiring harness for continuity and proper voltage supply from the ECM.
- Replace the crankshaft position sensor if the wiring is confirmed to be in good condition.
- Check the timing components if the sensor replacement does not resolve the issue.
Estimated Repair Costs (2026)
| Job | Parts ($) | Labor ($) |
|---|---|---|
| Sensor Cleaning/Connector Repair | 0 – 20 | 50 – 150 |
| Crankshaft Sensor Replacement | 40 – 150 | 100 – 300 |
| Wiring Harness Repair | 20 – 100 | 150 – 400 |
Note: these are 2026 estimates in US dollars; costs vary by make and model.
Frequently Asked Questions
Can I drive with the P0335 code?
It is not recommended. Because the engine cannot accurately time ignition, you risk stalling in traffic, which is dangerous. Furthermore, driving with a bad sensor can lead to engine misfires that may damage your catalytic converter.
How do I clear the P0335 code?
You can clear the code using a standard OBD-II scanner. However, clearing the code does not fix the underlying mechanical or electrical fault; the light will likely return quickly if the sensor or wiring is truly damaged.
Why does my car stall only when the engine is hot?
This is a classic sign of a failing crankshaft sensor. As the sensor heats up, internal electrical resistance changes, causing the internal circuitry to fail. Once the engine cools down, the sensor may temporarily function again until it reaches operating temperature.