P0335 on the 6.7L Power Stroke is a crankshaft position sensor code. The crank sensor is critical for the ECM to know engine position and speed, so a fault here can cause hard starts, stalling, or a no-start. Here is how to diagnose and fix it.
What P0335 means
P0335 is defined as Crankshaft Position Sensor A Circuit. The sensor reads a toothed reluctor wheel on the crankshaft to tell the ECM engine speed and position, which is essential for injection and timing. When the ECM loses the crank signal or sees it as out of range, it sets P0335. Because the engine depends on this signal, symptoms can be significant.
Common causes
- Faulty crankshaft position sensor
- Damaged, chafed, or open wiring in the sensor circuit
- Corroded or loose sensor connector
- Debris or damage on the reluctor/tone wheel
- Excessive air gap or a loose sensor mount
Symptoms
- Check engine light with stored P0335
- Hard starting or intermittent no-start
- Stalling, especially when hot
- Rough running or hesitation
- Tachometer dropping out or reading erratically
How to diagnose it
Inspect the crank sensor connector and wiring for damage, corrosion, or chafing, since heat and vibration take a toll near the engine. Check that the sensor is seated and mounted tightly. With a scan tool, watch RPM during cranking; a signal that drops out points to the sensor or wiring. Measure the sensor per specification and verify its ground and signal circuits. Confirm the tone wheel is intact and free of debris before replacing the sensor.
How to fix it
Replace the crankshaft position sensor if it tests faulty or the signal drops out. Repair damaged wiring and clean or replace a corroded connector, and ensure the sensor is torqued and seated correctly. Address any tone-wheel debris or damage. After the repair, clear the code, confirm a steady RPM signal during cranking and running, and verify starting is reliable and the code stays off.
Frequently asked questions
Can P0335 cause a no-start?
Yes. If the ECM loses the crankshaft position signal entirely, it cannot time injection and the engine may crank without starting.
Is P0335 the sensor or the wiring?
Both are possible. Inspect the connector and wiring first because they are common failure points, then test the sensor itself.
Why does my truck stall when hot?
A crank sensor that fails as it heats up can drop its signal at operating temperature, causing a hot stall that clears once it cools.
Need parts or a second opinion? The team at Core Diesel Parts can help you match the right components to your engine. Email sales@coredieselparts.com with your VIN and symptoms and we will point you to the correct parts.
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