P0335 Code: Crankshaft Position Sensor Circuit Malfunction
Causes, Symptoms, Diagnosis & Repair
If your vehicle cranks but does not start, stalls unexpectedly, has difficulty starting or develops an engine performance problem, an OBD-II scan may reveal the P0335 trouble code.
P0335 indicates a problem with the crankshaft position sensor circuit. The crankshaft position sensor, commonly called the CKP sensor, provides the engine control module with important information about crankshaft position and speed.
What Does P0335 Mean?
The diagnostic trouble code P0335 is a generic OBD-II code associated with the crankshaft position sensor circuit.
The CKP sensor monitors the position and rotational speed of the crankshaft. This information helps the engine control module determine important engine timing information.
Depending on the vehicle design, the crankshaft position sensor may use a magnetic, Hall-effect or other sensing technology.
When the engine computer does not receive the expected crankshaft position signal or detects a problem within the circuit, it may store P0335.
Common Symptoms of P0335
A vehicle with P0335 may experience one or more of these symptoms:
- Engine cranks but does not start
- Intermittent no-start condition
- Engine stalling
- Difficulty starting
- Rough or unstable idle
- Loss of engine power
- Hesitation during acceleration
- Check Engine Light
- Intermittent engine operation
Common Causes of P0335
P0335 does not automatically mean that the crankshaft position sensor itself has failed. Several faults can cause the code.
1. Faulty Crankshaft Position Sensor
A defective CKP sensor may produce a weak, missing or incorrect signal. Internal sensor failure can sometimes occur intermittently before the sensor fails completely.
2. Damaged Wiring
Broken wires, short circuits, open circuits or damaged insulation can interrupt the crankshaft sensor signal.
3. Poor Electrical Connection
Corrosion, loose terminals, damaged connector pins or poor contact at the CKP sensor connector can cause an intermittent or missing signal.
4. Incorrect Sensor Installation
If the sensor has been removed or replaced previously, incorrect installation, incorrect sensor positioning or an incorrect air gap where applicable can affect the signal.
5. Damaged Reluctor or Tone Wheel
The CKP sensor reads a rotating target such as a reluctor, tone wheel or toothed trigger depending on the engine design.
Damage, missing teeth, excessive contamination or mechanical movement of the target can interfere with the signal.
6. Electrical Power or Ground Problem
Some crankshaft position sensor systems require an appropriate power supply and ground. A problem with the supply circuit or ground can affect sensor operation.
7. Mechanical Engine Timing Problem
On some vehicles, a timing-chain or related mechanical problem can affect the relationship between the crankshaft and other engine timing signals.
8. ECU or Control Circuit Problem
Although less common, an engine control module or related circuit problem can contribute to crankshaft signal faults. This should generally be investigated only after the sensor and wiring have been properly tested.
How to Diagnose P0335
Proper diagnosis is important because replacing the CKP sensor without testing the circuit may not solve the problem.
Step 1 — Scan for Trouble Codes
Connect an OBD-II scanner and confirm P0335.
Check for additional codes that may provide information about the engine, camshaft position, ignition or electrical system.
Step 2 — Check Live Data
If the diagnostic scanner supports it, monitor engine RPM while cranking the engine.
A missing or abnormal RPM signal can provide an important clue that the engine computer may not be receiving a proper crankshaft position signal.
Step 3 — Inspect the CKP Sensor
Locate the crankshaft position sensor according to the vehicle manufacturer's service information.
Inspect the sensor for physical damage, contamination, loose mounting, incorrect installation or other visible problems.
Step 4 — Inspect the Connector
Disconnect the sensor connector where appropriate and inspect the terminals carefully.
Look for corrosion, bent terminals, damaged locking mechanisms, moisture or loose connections.
Step 5 — Check the Wiring
Follow the CKP sensor wiring back toward the engine harness and control module.
Look for wires that are broken, rubbed against metal, melted by engine heat, contaminated with oil or incorrectly repaired.
Step 6 — Test Power and Ground
Depending on the sensor design, verify the required power, ground and signal circuits using the manufacturer's wiring diagram and service specifications.
Do not assume every CKP sensor uses the same wiring configuration. Pin assignments and testing procedures vary between vehicles.
Step 7 — Check the Sensor Signal
Where appropriate, use suitable diagnostic equipment such as a multimeter or oscilloscope to evaluate the CKP signal.
An oscilloscope can be particularly useful when diagnosing intermittent crankshaft signal problems because it allows the technician to observe the actual waveform.
Step 8 — Inspect the Reluctor or Trigger Wheel
If the sensor and wiring appear to be functioning correctly, inspect the crankshaft trigger or reluctor system according to the vehicle's service procedure.
Step 9 — Check Mechanical Timing
If the electrical system tests correctly but the problem remains, investigate mechanical timing and the relationship between the crankshaft and camshaft signals.
🔧 Professional Diagnostic Tip
Do not replace a crankshaft position sensor simply because P0335 is stored. First determine whether the sensor is receiving the correct electrical supply, whether the wiring is intact and whether the sensor is producing the expected signal.
Can P0335 Cause a No-Start?
Yes. Depending on the vehicle's engine-management strategy, a missing crankshaft position signal can prevent the engine control module from determining crankshaft position and speed correctly.
This can result in a crank-but-no-start condition.
However, a no-start condition should not automatically be blamed on the CKP sensor. Fuel pressure, ignition, immobilizer, battery voltage, wiring and other engine-management systems may also need to be checked.
Can P0335 Cause Engine Stalling?
Yes. An intermittent crankshaft position signal can cause the engine computer to temporarily lose important engine-speed or position information.
Depending on the vehicle, this can contribute to sudden stalling or intermittent starting problems.
P0335 Repair Options
The appropriate repair depends on the confirmed cause.
- Replace a faulty crankshaft position sensor
- Repair damaged CKP sensor wiring
- Repair or replace damaged electrical connectors
- Correct power or ground circuit problems
- Correct improper sensor installation
- Repair a damaged reluctor or trigger system where applicable
- Correct mechanical timing problems
- Repair other confirmed engine-management circuit faults
Common Diagnostic Mistakes With P0335
- Replacing the CKP sensor without testing the circuit
- Ignoring sensor wiring
- Ignoring connector corrosion
- Using the wrong sensor for the vehicle
- Ignoring battery voltage during diagnosis
- Failing to check the crankshaft signal while cranking
- Ignoring mechanical timing problems
- Assuming every CKP sensor has the same wiring configuration
P0335 Does Not Always Mean a Bad Sensor
This is one of the most important things to understand about diagnostic trouble codes.
The phrase "Crankshaft Position Sensor Circuit Malfunction" refers to the system and circuit being monitored. The actual fault may be inside the sensor, in the wiring, connector, power supply, ground, signal circuit or another related component.
Proper testing should therefore come before parts replacement.
Final Advice
P0335 can be responsible for serious starting and drivability problems, but the code itself is only the beginning of the diagnostic process.
Start by confirming the code, checking related codes, inspecting the sensor and connector, testing the wiring and verifying the crankshaft signal.
If the electrical system checks out, continue with the appropriate mechanical and timing checks.
A systematic diagnosis can prevent unnecessary sensor replacement and help identify the real cause of the problem.
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