Crankshaft Position Sensor B Circuit Malfunction
The P0385 code indicates a malfunction in the circuit of the crankshaft position sensor B. This sensor monitors the rotational speed and position of the crankshaft, which is critical for engine timing and fuel injection. A circuit malfunction can be caused by a faulty sensor, damaged wiring, poor electrical connections, or issues with the engine control module (ECM). Without a proper signal, the engine may run poorly or not start.
01. Most Common Causes
- Faulty crankshaft position sensor B
- Damaged or corroded wiring/connectors
- Poor electrical connection
- Faulty engine control module (ECM)
02. Symptoms You Will Notice
- Engine cranks but does not start
- Intermittent stalling
- Check Engine Light illuminated
- Engine misfire or rough running
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 continuity and shorts in the circuit between sensor and ECM.
Step 5: Replace sensor if faulty; if not, inspect ECM and connections.
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 or fail to start, leading to a breakdown or accident.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, but can vary based on vehicle and shop rates.