P0385: Crankshaft Position Sensor B Circuit Malfunction
Can you still drive? Driving is not recommended. A failed crankshaft position sensor can cause sudden stalling, which is dangerous especially at highway speeds.
What Does P0385 Mean?
Code P0385 indicates a malfunction in the secondary crankshaft position sensor (sensor B) circuit. Some engines use two crankshaft position sensors for redundancy and more precise timing. When sensor B fails, the ECM may lose accurate crankshaft position data, affecting ignition timing and fuel injection.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Failed crankshaft position sensor B
- Damaged wiring or connector to sensor B
- Excessive gap between sensor and reluctor ring
- Damaged reluctor ring or tone wheel
- ECM internal fault
Symptoms
- Check engine light on
- Engine stalling
- Difficulty starting
- Rough or erratic idle
- Engine misfires
Diagnostic Steps
- 1Retrieve freeze frame data and note conditions at time of failure
- 2Inspect wiring and connector to crankshaft sensor B for damage
- 3Measure sensor resistance and compare to manufacturer specifications
- 4Check the air gap between the sensor and the reluctor ring
- 5Test sensor output signal with an oscilloscope while cranking
- 6Inspect the reluctor ring for missing or damaged teeth
Recommended Parts & Tools
crankshaft position sensor
wiring harness connector
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $400 |
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Chat with AI About P0385Commonly Affected Vehicles
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Frequently Asked Questions
What is the difference between sensor A and sensor B?
Sensor A is the primary crankshaft position sensor, while sensor B is a secondary sensor used on some engines for additional accuracy or redundancy. Not all engines have a sensor B.
Can a bad crankshaft sensor cause a no-start?
Yes. The crankshaft position sensor provides critical timing information to the ECM. Without it, the engine may not know when to fire the spark plugs or inject fuel, preventing the engine from starting.
Community Fix Reports
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