P0377
Timing Reference High Resolution Signal B Too Few Pulses
Timing reference signal B delivers fewer pulses per crank revolution than expected — broken reluctor teeth, sensor air gap too wide, or tone wheel chipped.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Tone wheel teeth broken or sensor gap excessiveCommon
Parts involved
- Camshaft Position Sensor
P0377 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.