OBD-II code · Powertrain (generic)
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.
Is it safe to drive with P0377?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyTone wheel teeth broken or sensor gap excessive
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- Parts involved
- Camshaft Position Sensor
Related codes
- P0372Timing Reference High Resolution Signal A Too Few Pulses
- P0374Timing Reference High Resolution Signal A No Pulses
- P0375Timing Reference High Resolution Signal B
- P0376Timing Reference High Resolution Signal B Too Many Pulses
- P0378Timing Reference High Resolution Signal B Intermittent/Erratic Pulses
- P0379Timing Reference High Resolution Signal B No Pulses
- P037AGlow Plug/Heater Indicator Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.