P0335: Crankshaft Position Sensor A Circuit Malfunction

What is the engine computer reporting with P0335?

The crankshaft position sensor is the primary signal the computer uses to know exact engine speed and piston position for both fuel injection and ignition timing on most modern engines. This code sets when that signal is missing or implausible, which on many engines will prevent the engine from starting or running at all rather than just illuminating a light. It is one of the more serious circuit codes because so many other systems depend on this one signal.

The code sits in the crankshaft position sensing area and is reported by the comprehensive component monitor. It names the circuit or the condition where the computer saw a reading outside its expected range. It does not name a failed part, and several genuinely different faults set this same code, which is the whole reason the causes below are ordered rather than listed.

What people usually notice

• Engine cranks but will not start
• Engine stalls suddenly and will not restart
• Intermittent stalling at idle or while driving
• No tachometer reading
• Engine runs rough then dies

What is actually behind P0335?

The causes below are ordered by how often they turn out to be the answer, cheapest and most common first. That order matters more than the list itself: the expensive component named in the code text is very rarely the first thing to replace, and working down from the top is what stops a crankshaft position sensing fault becoming an expensive guess.

Corroded or unplugged connector at the crank sensor is the one to rule out before anything else. This connector sits low on the engine near heat and road spray.

How do you diagnose P0335?

Start with freeze frame. Engine RPM at the fault shows whether the signal dropped out at a specific speed or only at idle. That snapshot is taken at the instant the code set, and it is the single most useful piece of evidence you have, which is also why clearing the code before reading it is such a costly habit.

This code is diagnosed by watching values change rather than by reading the number again, so the tool has to stream live data and hold freeze frame. A live scope trace of the crank sensor signal reveals dropouts and pattern damage that a simple code read cannot show.

The order worth working in

• 1. Corroded or unplugged connector at the crank sensor: This connector sits low on the engine near heat and road spray.
• 2. Chafed sensor wiring rubbing against a bracket or the timing cover: Engine vibration over years wears through insulation at contact points.
• 3. Excessive gap or debris between the sensor and the reluctor wheel: Metal shavings or an incorrect gap weaken the signal the sensor can read.
• 4. Failed crankshaft position sensor: These sensors are simple but do fail, especially with age and heat cycling.
• 5. Damaged reluctor wheel with broken or worn teeth: A physically damaged tone ring produces a signal the computer cannot interpret correctly.

Can you keep driving with P0335?

Stop driving if the engine stalls with this code, since it can shut off without warning at any speed and may not restart.

This is a severity 4 of 4 code, which means continuing to drive normally risks damage that costs considerably more than the repair in front of you. Treat the lamp as an instruction rather than a notification.

What does it cost to ignore P0335?

This sensor is central to both fuel and spark timing, so a failing signal tends to progress from intermittent stalling to a complete no-start, often with no further warning.

There is also the diagnostic cost of waiting. Freeze frame data, pending code history and the readiness monitor state all describe the fault as it was when it set, and all of it is lost the moment somebody clears the code to make the lamp go out.

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