Can I drive with a P0335 code?

No. P0335 typically prevents the engine from starting or causes it to stall unpredictably while driving. If the engine runs intermittently, it may stall without warning, creating a safety hazard. Repair the fault before driving.

How much does it cost to fix P0335?

A crankshaft position sensor replacement typically costs between $100 and $300 in parts and labor. If wiring repair or reluctor ring replacement is needed, costs can exceed $500 depending on engine access and labor rates.

Will P0335 clear itself?

The code may clear if the fault is intermittent and does not recur for several drive cycles. However, the underlying cause—usually a failing sensor or damaged wiring—will not resolve on its own and the code will return.

What is the difference between P0335 and P0016?

P0335 means the ECU cannot read the crankshaft position sensor signal. P0016 means the crankshaft and camshaft position sensors are both working, but their signals are out of sync, indicating a timing chain or belt issue.

Can a bad battery cause P0335?

A weak battery can cause low voltage during cranking, which may prevent the crankshaft position sensor from generating a strong enough signal. However, if the battery has enough power to crank the engine normally, it is unlikely to be the root cause.

P0335 Code Meaning: Crankshaft Position Sensor A Circuit

What P0335 Means

P0335 indicates the engine control unit (ECU) has lost or cannot interpret the signal from the crankshaft position sensor (CKP sensor A circuit). The crankshaft position sensor tells the ECU exactly where the crankshaft is in its rotation and how fast it is spinning, information the ECU uses to time fuel injection and ignition. Without this signal, the engine will not start or will stall unpredictably because the ECU cannot synchronize combustion events.

This code is defined by SAE J2012 as "Crankshaft Position Sensor A Circuit." It is a critical fault: the engine cannot run without a valid crankshaft position signal. If the sensor fails while driving, the engine will stall immediately. If it fails before startup, the engine will crank but not fire.

Symptoms of P0335

The most common symptom is an engine that cranks normally but will not start. The starter motor turns the engine over, but no combustion occurs because the ECU has no crankshaft position reference. In some cases the engine may start briefly then stall within seconds, or it may run for a while and stall randomly during driving.

Other symptoms include:

No tachometer reading, or the tachometer needle bounces erratically
Intermittent stalling that becomes more frequent over time
Check engine light illuminated (if the engine runs long enough to store the code)
No other driveability issues when the engine does run, because fuel and ignition timing may default to a backup strategy using the camshaft position sensor

If the code is intermittent, the problem is often a loose connector or damaged wiring that loses contact under vibration or temperature changes.

Common Causes Ranked by Likelihood

Failed crankshaft position sensor is the most common cause. The sensor itself wears out over time, especially in high-mileage vehicles or those exposed to heat and vibration near the crankshaft. Internal sensor faults prevent it from generating a signal the ECU can read.

Damaged or corroded wiring near the sensor is the second most likely cause. The crankshaft position sensor is often mounted low on the engine block, close to road spray, heat, and moving parts. Wiring insulation can crack, corrode, or chafe against the engine, causing opens or shorts.

Loose or corroded sensor connector can interrupt the signal intermittently. Corrosion on connector pins increases resistance, and a loose fit allows the connection to break under vibration.

Damaged reluctor ring (also called a tone wheel) on the crankshaft can prevent the sensor from generating a signal. The reluctor ring is a toothed wheel that passes by the sensor tip; missing teeth, cracks, or debris buildup will disrupt the magnetic field the sensor relies on.

Excessive air gap between the sensor tip and the reluctor ring can weaken the signal below the threshold the ECU requires. This can happen if the sensor is installed incorrectly or if the reluctor ring has shifted.

ECU fault is rare but possible. Internal ECU damage or a software fault can prevent the ECU from interpreting an otherwise valid sensor signal.

Diagnostic Path for P0335

Start by retrieving freeze-frame data to confirm the conditions when the code set. Freeze-frame will show engine RPM, coolant temperature, and other parameters at the moment of the fault. If RPM reads zero or very low while cranking, the ECU is not receiving a crankshaft position signal.

Visually inspect the crankshaft position sensor and its wiring. Look for physical damage, oil contamination, or loose mounting. Check the connector for bent pins, corrosion, or a loose fit. Clean the connector with electrical contact cleaner if corrosion is present, and ensure it clicks firmly into place.

Measure the sensor's resistance with a multimeter and compare the reading to the manufacturer's specification, typically between 200 and 1,000 ohms depending on the sensor type. A reading of infinite resistance indicates an open circuit inside the sensor; a reading of zero indicates a short. Either condition requires sensor replacement.

Inspect the reluctor ring if accessible. On some engines the ring is visible through an access port or by removing a cover; on others it requires significant disassembly. Look for missing or damaged teeth, cracks, or debris such as metal shavings stuck to the ring. Clean the ring carefully if debris is present.

Check the air gap between the sensor tip and the reluctor ring. Most sensors are non-adjustable and set the gap automatically when bolted in place, but verify the sensor is seated fully and the mounting bolt is tight. If the gap is adjustable, consult the service manual for the correct specification, typically 0.020 to 0.050 inches.

Test wiring continuity from the sensor connector back to the ECU. Check for opens, shorts to ground, and shorts to power. Repair or replace damaged wiring and secure it away from heat and moving parts.

Monitor the sensor signal with a scan tool or oscilloscope while cranking the engine. A healthy sensor produces a clean AC waveform that increases in frequency as RPM rises. No signal, a flat line, or an erratic waveform indicates a sensor or reluctor ring fault. If you see a signal at the sensor connector but the ECU reports no signal, suspect an ECU fault or a wiring issue between the connector and the ECU.

Reluctor ring inspection and replacement require engine disassembly on most vehicles, often involving removal of the timing cover or crankshaft pulley. This work warrants a qualified mechanic with the tools and service information for your specific engine.

Repair and Verification

If the sensor resistance is out of specification or no signal is present during cranking, replace the crankshaft position sensor. Use an OEM or high-quality aftermarket part; low-quality sensors are a common cause of repeat failures. Apply a thin coat of heat-resistant grease to the sensor O-ring if equipped, and torque the mounting bolt to specification.

Repair or replace damaged wiring, and secure the harness away from heat sources and moving components. Replace corroded connectors or repair them with dielectric grease to prevent future corrosion.

If the reluctor ring is damaged, it must be replaced. This is a labor-intensive repair that may require crankshaft removal on some engines. Clean any debris from the ring if it is otherwise intact.

After repairs, clear the code and attempt to start the engine. Verify the engine starts reliably and the tachometer reads correctly. Road test the vehicle under various conditions—cold start, hot restart, highway speed, stop-and-go traffic—to confirm the code does not return and the engine does not stall.

If the code returns immediately or the engine still will not start after sensor replacement and wiring repair, suspect a reluctor ring fault or an ECU issue. At that point, professional diagnosis with an oscilloscope and service information is the most efficient path forward.

Diagnostic output is a decision-support estimate, not a substitute for professional inspection.