OBD-II code · Powertrain (generic)
P0378 Timing Reference High Resolution Signal B Intermittent/Erratic Pulses
Timing reference signal B pulses are erratic — connector or wiring intermittent, contamination on tone wheel, or sensor partially failed.
Is it safe to drive with P0378?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyIntermittent connector or contamination
- Less likelyConnector with intermittent contact under vibration
- Less likelyHarness routed against vibrating component
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Camshaft Position Sensor
Related codes
- P0373Timing Reference High Resolution Signal A Intermittent/Erratic Pulses
- P0375Timing Reference High Resolution Signal B
- P0376Timing Reference High Resolution Signal B Too Many Pulses
- P0377Timing Reference High Resolution Signal B Too Few Pulses
- P0379Timing Reference High Resolution Signal B No Pulses
- P037AGlow Plug/Heater Indicator Control Circuit Low
- P037BGlow Plug/Heater Indicator Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.