P0335
Crankshaft Position Sensor A Circuit Malfunction
Encountering the engine check light code P0335 signifies an explicit mechanical or electrical operational breakdown categorized as "Crankshaft Position Sensor A Circuit Malfunction". Professional scanner tools usually flag this subsystem loop early on.
Driver's Summary
Storing code P0335 is your car's way of telling you something is wrong with the crankshaft position sensor a circuit malfunction. The most common signs are no start, engine stalling, erratic tachometer. This condition is classified as high severity. Prompt diagnosis is essential to prevent cascading damage to related components.
Symptoms
No start, engine stalling, erratic tachometer
Common Causes
- Faulty crank sensor
- Damaged reluctor ring
- Damaged wiring
- Interference from spark plug wires
How to Fix
- 1 Replace crank sensor
- 2 Inspect reluctor ring teeth
- 3 Repair wiring harness
- 4 Check battery voltage
Technical Explanation
P0335 is stored after the control module confirms the fault over multiple ignition cycles, ruling out transient electrical noise as the cause. For injector-specific codes, the ECM monitors the injector control circuit voltage drop during each pulse; a shorted or open injector presents a characteristic resistance signature that differs measurably from a healthy unit. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
An active P0335 code under high-severity conditions means the affected system is operating outside safe parameters. Continued driving — especially under load or at highway speeds — significantly increases the risk of secondary damage to components like damaged reluctor ring.
Mechanic's Pro Tip
The most common mistake with P0335 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
Sensor: $75 - $150; Labor: $100 - $300