OBD2 Diagnostic Code
P0335
Crankshaft Position Sensor Circuit Malfunction β Warning Signs & How to Fix It
P0335 is one of the few codes where the engine might refuse to start entirely β or die on you mid-drive with zero warning. But before you authorize a sensor replacement, there are two checks that cost nothing and resolve this in roughly 1 in 4 cases. Start there.
Severity
9 / 10
Critical. Engine stall or no-start is possible at any time without warning.
Safe to Drive?
No
Do not drive until diagnosed. An intermittent sensor can cause sudden engine shutdown in traffic.
Typical DIY Fix Cost
Low β Moderate
Wiring and connector issues often cost very little. Sensor replacement is affordable for most vehicles.
π What This Code Means
Your engine's computer β the ECM β cannot run the engine without knowing exactly where the crankshaft is at all times. It needs this to fire the spark plugs and inject fuel at precisely the right moment. The crankshaft position sensor (CKP) is the only thing providing that information.
P0335 means the ECM sent power to the CKP sensor and expected to receive a signal back, but got nothing β or got a signal so weak and erratic it couldn't trust it. This is not a performance issue. Without a valid crankshaft signal, the ECM simply refuses to allow the engine to run.
π‘ How it works: A toothed metal ring (called the reluctor wheel or tone ring) is pressed onto the crankshaft. As the crankshaft spins, each tooth passes the sensor tip and generates a small voltage pulse. The ECM counts these pulses β typically 58 teeth plus one gap β to know crankshaft speed (RPM) and position in real time.
P0335 is specifically a circuit malfunction code. That means it could be the sensor itself, the wiring harness to the sensor, the connector, or even the reluctor wheel. The code alone doesn't tell you which one β that's what the checks below are for.
β‘ Important: The ECM may also disable fuel injection and ignition as a safety measure when P0335 is active. This is why a no-start with no other obvious reason is one of the most common presentations of this code.
β‘ Common Symptoms
P0335 symptoms range from barely noticeable to completely undriveable, depending on whether the sensor failure is partial or total. These are the most reported warning signs.
Engine cranks but won't start
The starter motor spins the engine normally, but it never fires. Without a CKP signal, the ECM won't trigger ignition or injection. This is the most severe presentation.
Sudden stall while driving
Engine cuts out without warning at any speed β highway, city, or sitting at a light. An intermittent sensor can fail on a bump or when it gets hot, then restore itself after cooling down.
Rough or irregular idle
RPMs fluctuate erratically at a stop. The ECM is receiving a partial or noisy signal and struggling to maintain proper timing. Can feel like the engine is "hunting" for idle.
Hard starts when hot
Engine starts fine cold but takes many cranks after a short stop or after running errands. The sensor fails when heat-soaked and recovers once cooled β a classic thermal failure pattern.
Hesitation and misfires
Stumbling under acceleration, especially from a stop. Ignition timing is thrown off by a degraded signal. May trigger misfire codes (P030X) alongside P0335.
Tachometer drops to zero
RPM gauge falls to zero while the engine is still running β or bounces erratically. The tachometer reads directly from the CKP signal on most vehicles, so a bad sensor shows up there immediately.
π¨ If your engine has already stalled unexpectedly once with this code active, treat it as a breakdown waiting to happen. Do not drive on highways or in high-traffic situations until this is resolved.
π― Most Likely Causes
Listed from most to least common. The sensor itself is not always the problem β wiring and connector issues cause roughly 1 in 4 cases. Always check wiring before replacing any parts.
1
Failed crankshaft position sensorThe sensor's internal coil breaks down β often from heat cycling over time. Most common on high-mileage vehicles. A failed sensor typically reads open circuit (OL) on a multimeter when tested across the signal pins. Normal resistance is 200β1,000 ohms depending on manufacturer spec.
~ 45% of cases
2
Damaged or corroded wiring harnessThe sensor wiring runs close to the engine block, exhaust components, and moving parts. Chafed insulation, heat damage, or a wire that's rubbed through at a bracket can break the circuit intermittently or completely. Follow the harness from the sensor back toward the ECM looking for any obvious wear.
~ 20% of cases
3
Bad or corroded connector at the sensorThe two-pin or three-pin connector at the sensor is exposed to engine heat, oil, and vibration. Corrosion on the terminal pins increases resistance and weakens the signal. Disconnect the connector, spray with electrical contact cleaner, and inspect the pins β green or brown oxidation means the connector is compromised.
~ 15% of cases
4
Incorrect sensor air gapThe CKP sensor must sit at a precise distance from the reluctor wheel β typically 0.5 mm to 1.5 mm depending on the vehicle. If the sensor has been replaced before and wasn't seated fully, or if the mounting bracket is bent, the gap may be too wide to generate a clean signal even though the sensor itself is fine.
~ 10% of cases
5
Damaged or missing reluctor wheel toothA chipped, cracked, or missing tooth on the tone ring creates a dropout in the signal pattern. The ECM detects this as a circuit fault. Look for this after recent engine work, a front-end collision, or on high-mileage vehicles with oil seal leaks that could have exposed the ring to debris.
~ 7% of cases
6
ECM fault or power/ground issue to sensorRare but possible. The ECM provides reference voltage and ground to the CKP sensor. A blown fuse in the sensor circuit, a bad ECM ground, or (rarely) an internal ECM failure can mimic a sensor problem. Only investigate this after confirming the sensor, connector, and wiring are all healthy.
~ 3% of cases
π§ What to Check First
These three checks cost nothing and take about 30 minutes. In roughly one out of four P0335 cases, the problem is in the wiring or connector β not the sensor. Always rule these out before buying any parts.
1
Inspect the CKP sensor connector and wiring harnessLocate the crankshaft position sensor β it's usually mounted on the engine block near the bottom of the engine, close to the crankshaft pulley or flywheel. Disconnect the connector and look at both sides: the pins should be shiny and intact, not green, brown, or bent. Spray both sides with electrical contact cleaner and let dry. Then trace the wiring harness back toward the firewall, looking for spots where the insulation has worn through against a bracket, heat shield, or hose. Pay close attention anywhere the harness is clipped to the block β these are the highest-wear points.
2
Check the sensor air gap and mountingWith the connector unplugged, check that the sensor is bolted in all the way and the mounting bolt is snug. A sensor that has backed out even slightly may be too far from the reluctor wheel to generate a clean signal. On most vehicles the correct gap is 0.5 mm to 1.5 mm β about the thickness of a business card to a credit card. Some replacement sensors come with a paper shim to set this gap automatically; if yours came with one and it was removed too early, this is a likely cause.
3
Test sensor resistance with a multimeterSet your multimeter to Ohms (Ξ©). Unplug the sensor connector and probe across the two signal pins on the sensor side. A good CKP sensor reads between 200 and 1,000 ohms β check your vehicle's service manual for the exact spec. An open circuit reading (OL or infinite) means the internal coil is broken and the sensor must be replaced. A reading of 0 ohms (short circuit) also means a failed sensor. This test takes two minutes and tells you definitively whether the sensor has an internal fault.
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β οΈ Common Misdiagnosis
P0335 sounds straightforward β bad sensor, replace sensor. But these three assumptions cause unnecessary spending in a significant number of cases.
β Misdiagnosis #1 β Replacing the sensor before checking the wiring
A damaged wire or corroded connector produces an identical code to a dead sensor. The sensor costs more. The wiring repair often costs nothing but time. Any shop replacing the CKP sensor without first performing a visual harness inspection and connector check is skipping the logical first step. Ask to see evidence of both before authorizing a sensor replacement.
Potential savings: Sensor cost plus labor avoided if wiring is the real cause
β Misdiagnosis #2 β No-start blamed on fuel pump or ignition module
A no-start caused by P0335 is sometimes diagnosed as a bad fuel pump or faulty ignition module because the engine cranks without firing. The diagnostic shortcut here is the tachometer β if the RPM gauge stays at zero while cranking, the ECM is not receiving a crankshaft signal, and P0335 is the more likely cause. A fuel pump or ignition module failure shows a different pattern on the scanner.
Potential savings: Fuel pump replacement is a much larger investment than a sensor swap
β Misdiagnosis #3 β Camshaft sensor replaced instead of crankshaft sensor
P0335 is a crankshaft position sensor code. P0340 is a camshaft position sensor code. They're different sensors in different locations. On a first shop visit it is not unusual for the wrong sensor to be quoted, particularly if the technician is working from a symptom description rather than a confirmed code. Before authorizing any work, confirm the technician pulled codes from the OBD2 port and can show you P0335 specifically on their scanner.
Potential savings: Cost of the unnecessary camshaft sensor replacement
π° Estimated Repair Cost
DIY cost = parts only. Shop cost = parts plus labor. Access to the CKP sensor varies widely β on some vehicles it's a 20-minute job; on others the intake manifold or other components must come off first. Always get a quote specific to your vehicle.
Connector cleaning / wiring repair
DIYMinimal
ShopLow
LevelEasy
Crankshaft position sensor replacement
DIYLow
ShopLowβModerate
LevelEasyβModerate
CKP sensor (difficult access β timing cover removal)
DIYModerate
ShopModerateβHigh
LevelAdvanced
Wiring harness section replacement
DIYLowβModerate
ShopModerate
LevelModerate
Reluctor wheel replacement
DIYHigh
ShopVery High
LevelProfessional
ECM diagnosis / replacement
DIYNot recommended
ShopVery High
LevelProfessional
β
In most P0335 cases the repair is either a wiring fix (very low cost) or a sensor swap (affordable on most vehicles). Only a small percentage require anything more involved. Start cheap, work up.
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π Most Reported On
P0335 appears across virtually all gasoline-powered vehicles. These models report it most frequently based on owner data and verified repair records.
Nissan Altima (2002β2013, 2.5L QR25DE)
Nissan Maxima (2004β2014, 3.5L VQ35DE)
Ford F-150 (2004β2010, 4.6L / 5.4L Triton)
Dodge Ram 1500 (2003β2009, 4.7L / 5.7L HEMI)
Jeep Grand Cherokee (2005β2010, 3.7L / 4.7L)
Honda Accord (2003β2012, 2.4L K24)
Toyota Camry (2007β2014, 2.4L 2AZ-FE)
Chevrolet Silverado (2007β2014, 5.3L LS)
Hyundai Sonata (2006β2014, 2.4L / 2.7L)
Kia Optima (2007β2013, 2.4L)
β Frequently Asked Questions
Can I drive with P0335 active?
Not reliably. The engine may restart fine after a stall β or it may not start at all. P0335 is not a "wait and see" code. If the crankshaft sensor fails completely while driving, the engine shuts off with no warning. Have it checked before your next long trip, and avoid highways or heavy traffic situations until it's resolved.
Can a bad crankshaft sensor cause a no-start?
Yes, and this is one of the most common causes of a crank-but-no-start condition. Without a valid signal from the crankshaft position sensor, the ECM cannot time the ignition spark or fuel injection pulses. The starter motor cranks the engine normally, but it never fires. If your tachometer reads zero while cranking, P0335 is the first place to look.
Why does P0335 only happen when the engine is hot?
Heat causes metal and plastic to expand. A sensor with a hairline crack in the internal coil, or a wiring connector with marginal contact, will fail only when hot and restore itself after cooling. This pattern almost always points to the sensor itself rather than external wiring damage β a failing sensor shows thermal failure before it fails completely.
What is the reluctor wheel and why does it matter?
The reluctor wheel (also called the tone ring) is a toothed metal ring pressed onto the crankshaft. As each tooth passes the sensor tip, it generates a small voltage pulse. The ECM counts these pulses to know crankshaft speed and position. A missing, chipped, or debris-covered tooth breaks the signal pattern and sets P0335 β even if the sensor itself is perfectly healthy.
Can I test a crankshaft position sensor myself?
Yes. With an inexpensive multimeter, measure resistance across the two signal pins on the sensor connector (sensor side, connector unplugged). A healthy CKP sensor typically reads between 200 and 1,000 ohms β check your vehicle's service data for the exact specification. An open circuit reading (OL / infinite) means the sensor's internal coil has broken. Zero ohms (short circuit) also means a failed sensor. Either result points directly to sensor replacement.
π Related Codes
These codes share similar root causes or commonly appear alongside P0335.
This guide is for informational purposes only. Always consult a qualified mechanic before performing any vehicle repair. OBDPlatform is not responsible for actions taken based on this content.