Crankshaft Position Sensor A Circuit Malfunction
The P0335 code indicates that the Engine Control Module (ECM) has detected a malfunction in the crankshaft position sensor 'A' circuit. This sensor monitors the rotational speed and position of the crankshaft, which is critical for engine timing, fuel injection, and ignition. A failure can cause the engine to run poorly or not start at all.
01. Most Common Causes
- Faulty crankshaft position sensor
- Damaged or corroded wiring/connectors
- Incorrect sensor gap or mounting
- Faulty ECM (rare)
02. Symptoms You Will Notice
- Engine cranks but does not start
- Intermittent stalling or rough idle
- Check Engine Light illuminated
- Poor acceleration or hesitation
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the sensor and wiring for damage or corrosion.
Step 3: Test sensor resistance and voltage with a multimeter per manufacturer specs.
Step 4: Check sensor gap and alignment; adjust if necessary.
Step 5: If all else fails, replace the sensor and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The engine may stall unexpectedly or fail to start, leading to a breakdown or accident.
How much does it cost to fix?▼
Typically $50 to $150 for parts and labor, depending on vehicle make and sensor location.