Error code
OBD2 P0387
OBD2P0387
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Crankshaft Position Sensor 'B' Circuit Low.
Severity
moderateThe vehicle may still be drivable but with reduced performance and potential starting issues.
Summary
P0387 indicates that the crankshaft position sensor B is providing a low input signal to the ECM, which can affect engine timing and performance.
Symptoms
- Poor fuel economy
- Engine cranks but won't start
- Difficulty starting the engine
- Lack of power or poor acceleration
Common Causes
- Dead crankshaft position sensor B
- Poorly aligned sensor
- Starting problems (dead battery, worn starter)
- Electrical issues in the wiring harness
Diagnosis
- Check battery condition and starter functionality
- Inspect the wiring harness for any damage or corrosion
- Verify proper installation of sensor B, including correct air gap
- Use a multimeter to check signal strength at the ECM
Fixes
- Replace crankshaft position sensor B
FAQ
Can I drive with P0387?
You can drive but expect reduced performance and potential starting issues.
What causes a low input signal in the crankshaft position sensor B?
Common causes include a faulty sensor, poor alignment, electrical problems, or issues with the starter battery system.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
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