P0377
PowertrainCrankshaft Camshaft Positionmoderate severityTiming Reference High Resolution Signal B Too Few Pulses
What P0377 Means
The PCM received fewer high resolution timing pulses than expected on signal B. This may indicate a missing tooth on the tone ring or sensor fault.
Symptoms
- Check engine light on
- Poor performance
- Rough idle or misfire
Common Causes
- Damaged or worn tone ring
- Faulty timing sensor
- Excessive air gap
- Wiring fault
Diagnostic Steps
- Retrieve stored codes
- Inspect tone ring for missing teeth
- Measure sensor air gap
- Replace sensor if defective
🔌 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 P0377?
Help other technicians by sharing what worked on your vehicle.
Submit Your Fix