P0335
Crankshaft Position Sensor A Circuit Malfunction
Published · Reviewed and updated
In plain English: The engine computer lost the crankshaft speed-and-position signal it needs to control ignition and injection; P0335 identifies the signal circuit, not automatically a failed sensor.
A missing crank signal can stall the engine or prevent the next restart. If the engine has stalled, cranks without starting, or the tachometer and scan-tool RPM drop out, arrange a tow. Even if it currently runs normally, an intermittent P0335 should be diagnosed before routine driving.
A diagnostic starting point: Failed crankshaft position sensor. Start by asking: Does the engine crank at normal speed with stable battery voltage? Illustrative parts budgets span $0–$1500 USD, with diagnosis, labor and taxes extra.
Quick answers about P0335
- What does P0335 mean?
- The engine computer lost the crankshaft speed-and-position signal it needs to control ignition and injection; P0335 identifies the signal circuit, not automatically a failed sensor.
- What should I check first for P0335?
- One starting point is Failed crankshaft position sensor. Internal windings or electronics can fail permanently or open only when hot. Test the signal before replacing it. The code alone does not identify a failed part; follow the procedure for your vehicle.
- Can I drive with P0335?
- A missing crank signal can stall the engine or prevent the next restart. If the engine has stalled, cranks without starting, or the tachometer and scan-tool RPM drop out, arrange a tow. Even if it currently runs normally, an intermittent P0335 should be diagnosed before routine driving.
- How much does it cost to fix P0335?
- Illustrative parts budgets in this guide span $0–$1500 USD. Diagnosis, labor and taxes are extra. P0335 may be an inexpensive terminal repair or an internal reluctor job. The waveform path prevents a good sensor from being replaced when the signal is lost in the harness.
- How do I diagnose P0335?
- Start with: Does the engine crank at normal speed with stable battery voltage? Start with the physical crank and electrical supply. A weak battery, dragging starter or damaged engine ground can lower signal amplitude and prevent a valid test. Use the vehicle's cranking-voltage and speed specifications.
Watch the P0335 videos
Full walkthrough — 9:04. Watch on YouTube
What P0335 actually means
A toothed reluctor rotates with the crankshaft. As each tooth passes the crankshaft position sensor, the sensor creates a voltage or digital pulse. The engine computer counts those pulses to calculate cranking and running speed, recognize crank position, and schedule spark and fuel injection at the correct time.
P0335 sets when the expected primary crankshaft signal is absent or electrically invalid while the computer believes the engine is cranking or running. Depending on the vehicle, the monitor can detect no pulses, an open circuit, a short to ground or voltage, or a signal that never switches. The code covers the entire circuit and cannot convict the sensor by itself.
Symptoms
- Engine cranks but will not startWithout crank position, many controllers will not command normal spark or injector operation.
- Sudden stall followed by a difficult or impossible restartHeat can open an internally failing sensor or connection and let it work again after cooling.
- Tachometer or scan-tool RPM remains at zero while crankingThat is a strong direction toward the crank signal, but a scope test is the proof.
- Intermittent hesitation, cut-out or extended crankingA loose terminal, damaged wire or marginal air gap may lose only an occasional pulse.
- Check-engine light with P0336 or cam/crank correlation codesCompanion codes help separate a dead circuit from an incorrect or out-of-sync pattern.
Possible causes and what to check
This is a practical diagnostic order, not measured failure rates. Follow the tests and priorities specified for your vehicle; a code alone does not identify a failed part.
The first clue: engine RPM while cranking
Illustrative graph, not a recording from your vehicle or a universal service limit. Confirm the test conditions, units and acceptance criteria in the applicable service procedure.
Connect the scan tool, keep the battery supported, and graph engine speed while cranking for several seconds. Confirm that the starter is actually turning the engine at a normal, even speed.
A known-good signal rises promptly to a steady cranking speed. That proves the computer is receiving enough crank information to calculate RPM at this moment, although an intermittent dropout may still need heat and harness testing.
A flat zero-RPM trace while the crankshaft is physically turning points toward a missing crank signal, its power or ground, the wiring, or the reluctor and air gap. Do not order a sensor from this clue alone.
Scan RPM is the fast screening test; a waveform measured at the sensor and then at the computer is the decisive test. If the waveform leaves the sensor but never reaches the PCM, the sensor is not the failed part.
How to diagnose it, in order
-
Does the engine crank at normal speed with stable battery voltage?Start with the physical crank and electrical supply. A weak battery, dragging starter or damaged engine ground can lower signal amplitude and prevent a valid test. Use the vehicle's cranking-voltage and speed specifications.Yes → go to step 2No → Repair the battery, cables, ground or starter condition
-
Does the scan tool show steady engine RPM while the engine is cranking?Graph RPM rather than watching one slowly updating number. A stable value means the PCM sees a crank signal now. Zero or repeated dropouts tell you to move from code reading to circuit measurement.Yes → Capture the intermittent with heat, wiggle and CKP/CMP sync testsNo → go to step 3
-
Do required power, ground and circuit-bias checks match factory specification?Identify whether the vehicle uses a powered three-wire Hall sensor or a two-wire variable-reluctance sensor before testing. Never apply a generic voltage rule to the wrong sensor design.Yes → go to step 4No → Repair the missing supply, ground, bias or connector terminal
-
Is the correct CKP waveform present directly at the sensor while cranking?Use the specified meter or oscilloscope connection and compare amplitude, switching and tooth pattern with service information. Back-probe safely so the test does not spread or damage terminals.Yes → Trace the signal wire to the PCM and repair where it disappearsNo → go to step 5
-
Are sensor mounting, air gap and reluctor teeth mechanically correct?Inspect for a loose sensor, debris on a magnetic tip, impact damage and a shifted or broken tone wheel. Some reluctors require a borescope or substantial disassembly to inspect.Yes → Replace the signal-tested failed crankshaft sensorNo → Correct the mounting, air gap or damaged reluctor
Follow the signal from the rotating crankshaft to the computer. The point where it disappears identifies the branch to repair.
What you need to do this yourself
- A scan tool that reads live data — Choose vehicle-compatible access to the live data, freeze frame and monitor results required by the diagnostic procedure. Some checks also need bidirectional control.
- Digital multimeter — Use the specified meter and test method for electrical checks. Follow circuit diagrams and avoid applying an unsuitable test load to a computer driver.
- Vehicle-specific service information — Confirm the procedure, safety precautions, tools and acceptance limits for the exact year, model and engine.
Some links may be affiliate links. They cost you nothing extra and do not change which tools are recommended — the diagnostic order on this site is the same either way.
Illustrative repair budgets
These are rough US planning examples, not quotes or measured repair averages. Parts and labor are separate; diagnosis, taxes, difficult access and additional repairs can increase the total.
| Repair | Parts (USD) | Labor time |
|---|---|---|
| Connector or accessible wiring repair Cost rises when the damaged section is buried behind covers or the transmission. |
$10–$250 | 1.5 h |
| Crankshaft position sensor Access ranges from one exposed bolt to removal of other components. |
$25–$250 | 1.0 h |
| Battery, cable or starter correction Only belongs here when cranking voltage or speed fails its test. |
$20–$500 | 1.0 h |
| Reluctor wheel, air-gap or mounting repair Some tone wheels are internal and require transmission or engine disassembly. |
$50–$600 | 5.0 h |
| PCM calibration, input repair or module The rare final branch after a correct waveform has been proven at the PCM pins. |
$0–$1500 | 1.5 h |
P0335 may be an inexpensive terminal repair or an internal reluctor job. The waveform path prevents a good sensor from being replaced when the signal is lost in the harness.
P0335 video summary · 1:08
A brief introduction to the code and a diagnostic starting point. Use the full guide and vehicle-specific service information for the complete procedure.
Written diagnostic walkthrough
Current written guidance organized by topic. This text may include corrections made after a video was published and is not a verbatim transcript of the archived video.
Meaning and driving guidance
Code P0335. Crankshaft Position Sensor A Circuit Malfunction.
In plain English: the engine computer lost the crankshaft speed-and-position signal it needs to control ignition and injection; P0335 identifies the signal circuit, not automatically a failed sensor.
A missing crank signal can stall the engine or prevent the next restart. If the engine has stalled, cranks without starting, or the tachometer and scan-tool RPM drop out, arrange a tow. Even if it currently runs normally, an intermittent P0335 should be diagnosed before routine driving.
How it is measured
Here's what your engine computer is actually measuring.
A toothed reluctor rotates with the crankshaft. As each tooth passes the crankshaft position sensor, the sensor creates a voltage or digital pulse. The engine computer counts those pulses to calculate cranking and running speed, recognize crank position, and schedule spark and fuel injection at the correct time.
P0335 sets when the expected primary crankshaft signal is absent or electrically invalid while the computer believes the engine is cranking or running. Depending on the vehicle, the monitor can detect no pulses, an open circuit, a short to ground or voltage, or a signal that never switches. The code covers the entire circuit and cannot convict the sensor by itself.
So the code is not a part failure report. It's a performance measurement that came back under spec.
Symptoms
What you'll usually notice, beyond the light itself.
Engine cranks but will not start. Without crank position, many controllers will not command normal spark or injector operation.
Sudden stall followed by a difficult or impossible restart. Heat can open an internally failing sensor or connection and let it work again after cooling.
Tachometer or scan-tool RPM remains at zero while cranking. That is a strong direction toward the crank signal, but a scope test is the proof.
Intermittent hesitation, cut-out or extended cranking. A loose terminal, damaged wire or marginal air gap may lose only an occasional pulse.
Check-engine light with P0336 or cam/crank correlation codes. Companion codes help separate a dead circuit from an incorrect or out-of-sync pattern.
Possible causes
Here is a practical order for checking the possible causes. These are diagnostic priorities, not measured failure rates.
Check 1: Failed crankshaft position sensor. Internal windings or electronics can fail permanently or open only when hot. Test the signal before replacing it.
Check 2: Chafed wiring or a loose, oil-contaminated connector. The circuit lives near heat, vibration and moving engine parts; inspect the entire routed harness.
Check 3: Missing sensor power, ground or circuit bias. Powered Hall-effect sensors need a clean supply and ground, while two-wire sensors require their own factory test method.
Check 4: Damaged reluctor wheel, wrong air gap or loose sensor mounting. A good sensor cannot create the correct pattern if teeth are damaged or it sits too far from the target.
Check 5: Low cranking voltage, slow starter speed or electrical noise. Weak voltage can reduce signal quality and can also make a no-start look like a sensor failure.
Check 6: Control-module calibration or PCM input fault. Check application-specific service information only after the signal has been verified at the controller.
Use the test results to choose the repair. A position in this list does not prove that a part has failed.
Illustrative diagnostic pattern
This illustrative graph explains a diagnostic pattern. Use the vehicle-specific procedure to interpret it.
Connect the scan tool, keep the battery supported, and graph engine speed while cranking for several seconds. Confirm that the starter is actually turning the engine at a normal, even speed.
A known-good signal rises promptly to a steady cranking speed. That proves the computer is receiving enough crank information to calculate RPM at this moment, although an intermittent dropout may still need heat and harness testing.
A flat zero-RPM trace while the crankshaft is physically turning points toward a missing crank signal, its power or ground, the wiring, or the reluctor and air gap. Do not order a sensor from this clue alone.
Scan RPM is the fast screening test; a waveform measured at the sensor and then at the computer is the decisive test. If the waveform leaves the sensor but never reaches the PCM, the sensor is not the failed part.
Diagnostic steps
So here is the order to actually test this, cheapest and most likely first.
Step 1. Does the engine crank at normal speed with stable battery voltage? Start with the physical crank and electrical supply. A weak battery, dragging starter or damaged engine ground can lower signal amplitude and prevent a valid test. Use the vehicle's cranking-voltage and speed specifications.
Step 2. Does the scan tool show steady engine RPM while the engine is cranking? Graph RPM rather than watching one slowly updating number. A stable value means the PCM sees a crank signal now. Zero or repeated dropouts tell you to move from code reading to circuit measurement.
Step 3. Do required power, ground and circuit-bias checks match factory specification? Identify whether the vehicle uses a powered three-wire Hall sensor or a two-wire variable-reluctance sensor before testing. Never apply a generic voltage rule to the wrong sensor design.
Step 4. Is the correct CKP waveform present directly at the sensor while cranking? Use the specified meter or oscilloscope connection and compare amplitude, switching and tooth pattern with service information. Back-probe safely so the test does not spread or damage terminals.
Step 5. Are sensor mounting, air gap and reluctor teeth mechanically correct? Inspect for a loose sensor, debris on a magnetic tip, impact damage and a shifted or broken tone wheel. Some reluctors require a borescope or substantial disassembly to inspect.
Follow the signal from the rotating crankshaft to the computer. The point where it disappears identifies the branch to repair.
Illustrative repair budgets
These are illustrative US parts budgets with labor shown separately. Diagnosis, taxes, access and additional repairs can change the total.
Connector or accessible wiring repair: 10 to 250 dollars in parts, plus about 1.5 hours of labor. Cost rises when the damaged section is buried behind covers or the transmission.
Crankshaft position sensor: 25 to 250 dollars in parts, plus about 1.0 hours of labor. Access ranges from one exposed bolt to removal of other components.
Battery, cable or starter correction: 20 to 500 dollars in parts, plus about 1.0 hours of labor. Only belongs here when cranking voltage or speed fails its test.
Reluctor wheel, air-gap or mounting repair: 50 to 600 dollars in parts, plus about 5.0 hours of labor. Some tone wheels are internal and require transmission or engine disassembly.
PCM calibration, input repair or module: 0 to 1500 dollars in parts, plus about 1.5 hours of labor. The rare final branch after a correct waveform has been proven at the PCM pins.
P0335 may be an inexpensive terminal repair or an internal reluctor job. The waveform path prevents a good sensor from being replaced when the signal is lost in the harness.
Sources and application limits
This legacy guide has not yet had a page-specific source list added. Check the factory service information for your exact year, make, model and engine before acting on a test or specification.