Last Updated on October 11, 2026
When your vehicle’s OBD2 scanner shows code P0335, it indicates a problem with the Crankshaft Position Sensor (CKP) circuit. This sensor plays an important role in engine performance. It helps the Engine Control Module (ECM) determine the crankshaft’s position and rotational speed.
Without a reliable crankshaft position signal, the ECM may struggle to control ignition timing and fuel injection. Your engine might misfire, stall unexpectedly, become difficult to start, or refuse to start altogether.
However, code P0335 doesn’t automatically mean the crankshaft position sensor is bad. Damaged wiring, poor connections, a faulty reluctor ring, or other electrical problems can trigger the same code.
Understanding these possibilities can save you from replacing parts unnecessarily. Let’s look at what causes P0335, how to recognize the symptoms, and what to check before making repairs.
What Does Code P0335 Mean?
Code P0335 means Crankshaft Position Sensor “A” Circuit Malfunction. It appears when the ECM or Powertrain Control Module (PCM) detects a missing or abnormal signal from the crankshaft position sensor circuit.
The crankshaft converts the pistons’ up-and-down movement into rotational motion. The CKP sensor monitors this rotation and sends information to the engine computer.
The ECM uses that information to calculate engine speed and determine when to operate the fuel injectors and ignition system, depending on the engine design.
If the signal disappears or becomes unreliable, the engine may not operate correctly.
For a closer look at how this component fails, see our guide to bad crankshaft position sensor symptoms and diagnosis.
Causes and Symptoms of Trouble Code P0335
Several electrical and mechanical problems can trigger code P0335. Identifying the actual cause is important because replacing the sensor won’t help if the problem lies elsewhere.
Common Causes of Code P0335
- Faulty Crankshaft Position Sensor: A damaged or failing sensor may stop producing a reliable signal.
- Damaged Wiring: Broken, shorted, or frayed wires can interrupt communication with the ECM.
- Loose or Corroded Connectors: Poor electrical contact can cause intermittent signal loss.
- Damaged Reluctor Ring: Missing teeth, damage, or incorrect alignment can affect sensor readings.
- Incorrect Sensor Installation: Improper mounting or clearance may prevent the sensor from reading the reluctor correctly.
- Timing System Problems: Certain engine designs may set this code when mechanical problems affect the crankshaft signal.
- Faulty ECM or PCM: An internal computer problem is possible, although less common than sensor or wiring faults.
Common Symptoms of Code P0335
If your car stores P0335, you might notice one or more of these symptoms:
- Check Engine Light: The warning light illuminates when the ECM detects a fault.
- Difficulty Starting: The engine may crank longer than usual before starting.
- No-Start Condition: Some vehicles won’t start without a valid crankshaft signal.
- Engine Stalling: The engine may shut off during idle or while driving.
- Rough Engine Performance: Misfires, hesitation, or uneven running may occur.
- Sudden Power Loss: The engine may briefly hesitate or lose power when the signal becomes unstable.
These symptoms aren’t exclusive to the crankshaft position sensor. Other ignition, fuel, and electrical problems can cause similar behavior.
If the Check Engine Light comes on, don’t simply erase it. Our guide on resetting the Check Engine Light explains why the underlying fault should be addressed first.
Diagnosing Code P0335 Like a Pro (DIY + Advanced)
Diagnosing code P0335 starts with an OBD2 scanner and a careful inspection. Basic checks are usually straightforward, but advanced electrical testing may require a wiring diagram and professional equipment.
Step 1: Scan for Trouble Codes
Connect your OBD2 scanner and check for stored, pending, and related diagnostic trouble codes.
Pay attention to codes involving the camshaft position sensor, ignition system, or electrical circuits. Multiple codes may point toward a shared problem.
Save the freeze-frame information before clearing anything. This data can show the engine conditions when the fault occurred.
If you’re unsure how to interpret those readings, read our guide on understanding OBD2 freeze-frame data.
Step 2: Check Live RPM Data
One useful diagnostic step is checking engine RPM while cranking.
Set your scanner to display live engine speed. Have someone crank the engine while you monitor the reading safely.
If the scanner repeatedly shows zero RPM during cranking, the ECM may not be receiving a usable crankshaft position signal.
However, a zero reading doesn’t prove the sensor itself has failed. Scanner limitations, wiring faults, and other problems must also be considered.
If the scanner displays RPM normally, continue testing. Intermittent sensor faults may still be present.
Step 3: Inspect Wiring and Connectors
Locate the CKP sensor using your vehicle’s service information. Depending on the engine, it may be near the crankshaft pulley, engine block, flywheel, or transmission bellhousing.
Inspect the connector and nearby wiring for:
- Broken or damaged insulation
- Loose electrical connections
- Corroded terminals
- Oil or moisture contamination
- Wires rubbing against moving or hot components
Repair any visible problems before replacing the sensor.
Step 4: Test the Crankshaft Position Sensor
Not every crankshaft position sensor operates the same way. Two common designs are magnetic (variable-reluctance) sensors and Hall-effect sensors.
Magnetic sensors generally produce an AC signal as the reluctor rotates. Hall-effect sensors use electrical power and typically produce a switching signal.
This distinction matters because the testing procedures are different.
Use the manufacturer’s wiring diagram to identify the sensor type, expected voltage, and correct test points.
Never assume every CKP sensor should produce a 5-volt square-wave signal. Some use different voltage levels or signal patterns.
An oscilloscope is often the best tool for examining the signal while the engine cranks or runs.
Step 5: Inspect the Reluctor Ring
The reluctor ring, sometimes called a tone wheel or trigger wheel, works with the CKP sensor to generate crankshaft position information.
If the ring has damaged teeth, excessive movement, or incorrect alignment, the sensor may produce an abnormal signal even when it’s working properly.
Inspect the ring according to your vehicle’s service procedure. On some engines, accessing it requires considerable disassembly.
Step 6: Check the ECM and Related Circuits
If the sensor, wiring, and reluctor ring pass inspection, further diagnosis may involve the ECM’s signal input and related circuits.
A technician can use an oscilloscope and manufacturer-specific diagnostic information to determine whether the signal reaches the computer correctly.
ECM replacement should be considered only after other possible causes have been ruled out.
Common Diagnostic Mistakes
- Replacing the crankshaft sensor without checking its wiring
- Clearing codes before saving diagnostic information
- Assuming zero RPM always means a bad sensor
- Ignoring a damaged or misaligned reluctor ring
- Using the wrong test procedure for the sensor type
- Overlooking battery or cranking-speed problems
How to Fix Code P0335
Once you’ve identified the problem, follow the appropriate repair procedure. The correct fix depends on what failed during diagnosis.
1. Replace the Crankshaft Position Sensor
If testing confirms that the CKP sensor has failed, replace it with a compatible part.
Disconnect the battery if instructed by the service manual, locate the sensor, and follow the manufacturer’s removal and installation procedure.
Some vehicles require a crankshaft position variation relearn after sensor replacement. Check whether your model needs this procedure before completing the repair.
2. Repair Wiring and Connectors
If the problem involves damaged wires or corroded connectors, repair those components using suitable automotive wiring methods.
Ensure the connector fits securely and that repaired wires are protected from engine heat and moving parts.
3. Repair the Reluctor Ring or Timing Components
If testing reveals a damaged reluctor ring or related mechanical problem, repair or replace the affected component.
Depending on the engine, this may involve removing the crankshaft pulley, timing cover, or other components.
Timing system repairs require accurate alignment. Incorrect installation can cause serious engine problems.
4. Inspect the ECM
If all sensor and circuit tests pass, the ECM may require professional testing.
Some faults can be corrected through wiring repairs or approved software procedures. A confirmed defective ECM may need replacement and programming.
5. Clear the Code and Test Drive
After completing the repair, clear the stored trouble codes using your scanner.
Start the engine and check for rough running, hesitation, or starting problems. If the vehicle operates normally and is safe to drive, perform a short test drive.
Scan the vehicle again afterward. Remember that some intermittent faults only return under specific operating conditions.
How Serious Is Code P0335?
Code P0335 should be treated seriously because the crankshaft position signal is essential for normal engine operation.
Depending on the vehicle and the nature of the failure, the engine may stall unexpectedly or refuse to restart.
It’s particularly risky to continue driving if your vehicle already experiences sudden power loss, repeated stalling, or severe misfires.
If the engine stalls while driving, steering and braking assistance may be reduced on some vehicles. Move to a safe location if possible and arrange towing rather than attempting to continue the trip.
Although P0335 doesn’t automatically mean the engine is being physically damaged, ignoring a serious or intermittent failure can leave you stranded.
Estimated Cost to Repair Code P0335
The cost to fix code P0335 depends on the vehicle, the cause, and labor rates in your area.
Here are broad U.S. repair-budget estimates, including parts and labor where applicable:
| Component or Service | Estimated Cost (USD) |
|---|---|
| Diagnostic Inspection | $100–$200+ |
| Crankshaft Position Sensor Replacement | $150–$450+ |
| Wiring or Connector Repair | $100–$350+ |
| Timing Belt Replacement | $500–$1,200+ |
| Timing Chain or Reluctor Repair | $800–$2,500+ |
| ECM/PCM Replacement and Programming | $600–$1,800+ |
Note: These figures are general estimates, not vehicle-specific quotes. Complex repairs can cost considerably more. Only the confirmed cause of the fault should be repaired.
Code P0335 vs. Similar Trouble Codes
Several OBD2 codes relate to crankshaft or camshaft position signals. Understanding the differences can help you narrow down the problem.
| Trouble Code | Description | What to Investigate |
|---|---|---|
| P0335 | Crankshaft Position Sensor “A” Circuit | Missing or abnormal CKP circuit signal |
| P0336 | Crankshaft Position Sensor “A” Circuit Range/Performance | Signal pattern, sensor position, or reluctor problems |
| P0339 | Crankshaft Position Sensor “A” Circuit Intermittent | Intermittent signal loss, wiring, or sensor failure |
| P0340 | Camshaft Position Sensor “A” Circuit | Camshaft sensor signal or related wiring problems |
These codes may cause similar symptoms, but their diagnostic procedures aren’t identical. Always identify the exact stored code before replacing parts.
How the Crankshaft Position Sensor Works
The CKP sensor works with a rotating reluctor ring or another crankshaft-mounted target.
As the crankshaft turns, the target passes the sensor. The sensor generates electrical information that the ECM uses to calculate crankshaft position and engine speed.
Depending on the engine, the ECM uses this information along with other signals to control ignition timing, fuel injection, and related functions.
If the signal becomes unreliable, the engine computer may no longer have the information it needs to operate those systems correctly.
When Should You Call a Mechanic?
Some P0335 problems, such as a loose connector or accessible damaged wire, may be straightforward to identify.
However, professional diagnosis is recommended if the engine repeatedly stalls, won’t start, or continues storing the code after basic inspections.
A qualified mechanic can use advanced scanning equipment, an oscilloscope, and vehicle-specific service information to locate the fault without guessing.
Final Thoughts on Code P0335
Code P0335 indicates a problem with the crankshaft position sensor circuit, but it doesn’t necessarily mean the sensor itself has failed.
Start by checking related trouble codes, live RPM data, wiring, and electrical connections. If those checks don’t reveal the problem, further testing of the sensor, reluctor ring, and ECM may be necessary.
The most important thing is to identify the failed component before replacing anything. A careful diagnosis can save money, prevent unnecessary repairs, and help keep your engine running reliably.
Frequently Asked Questions About Code P0335
1. What does code P0335 mean on a car?
Code P0335 means the engine computer detected a problem with the Crankshaft Position Sensor “A” circuit. The fault may involve the sensor, wiring, reluctor ring, or other related components.
2. Is it safe to drive with code P0335?
Driving with P0335 isn’t recommended, especially if your engine stalls, hesitates, or has trouble starting. An unreliable crankshaft signal can cause sudden engine shutdown.
3. What causes code P0335 to appear?
Common causes include a faulty crankshaft position sensor, damaged wiring, loose connectors, a damaged reluctor ring, or a problem with the ECM. The exact cause requires testing.
4. How do I fix code P0335 myself?
Start by scanning for related codes, inspecting the CKP sensor connector, checking accessible wiring, and reviewing live RPM data. Replace the sensor only if testing supports that diagnosis. More complex electrical or timing repairs are best handled by a professional.
5. How much does it cost to fix code P0335?
A crankshaft position sensor replacement may cost approximately $150–$450 or more in the U.S., depending on the vehicle. Wiring repairs and mechanical problems can change the total cost significantly.
6. Will replacing the crankshaft sensor fix P0335?
Yes, if the sensor is actually defective. However, replacing it won’t solve problems caused by damaged wiring, incorrect sensor clearance, a faulty reluctor ring, or an ECM issue. Proper testing should come first.