P0387
PowertrainCrankshaft Camshaft Positionmoderate severityCrankshaft Position Sensor B Circuit Low Input
What P0387 Means
The PCM detected an abnormally low voltage signal from crankshaft position sensor B. This can compromise timing accuracy and engine operation.
Symptoms
- Check engine light on
- Hard starting
- Stalling or rough running
Common Causes
- Faulty crankshaft position sensor
- Short to ground in wiring
- Corroded connector
- Faulty PCM
Diagnostic Steps
- Retrieve codes and freeze frame
- Inspect wiring for shorts to ground
- Check connector and grounds
- Test and replace sensor if needed
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Community Confirmed Fixes
No confirmed fixes yet for this code. Be the first to contribute!
Submit a FixFound a Fix for P0387?
Help other technicians by sharing what worked on your vehicle.
Submit Your Fix