Timing Reference High Resolution Signal B Too Few Pulses
The P0373 code means the vehicle's onboard diagnostic system has detected: Timing Reference High Resolution Signal B Too Few Pulses. This is a critical severity code.
- Keep driving?
- No — stop driving
- DIY difficulty
- hard
- Estimated cost
- $100 - $700 (parts and labor)
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What Are the Symptoms of P0373?
- Check Engine Light on
- Engine misfire or rough running
- Possible no-start condition
- Erratic idle
What Causes P0373? (Most Likely First)
- Damaged camshaft position sensor reluctor Very High
- Faulty camshaft position sensor B High
- Wiring damage to cam sensor B Moderate
- Timing chain stretch or jump Low
Can I Still Drive with P0373?
No — stop driving. P0373 is rated critical severity. Continuing to drive in this state risks further damage — get it looked at before your next trip.
Frequently Asked Questions
What is timing signal B?
Signal B typically refers to the Bank 2 camshaft position sensor. Engines with dual overhead cams or V-configuration engines have multiple timing signals.
Can a timing chain cause P0373?
Yes, a stretched or jumped timing chain can cause the camshaft reluctor to be out of position, generating incorrect pulse counts.
Is P0373 related to the crankshaft sensor?
No, P0373 is specific to the camshaft position signal. However, if the timing chain has jumped, both crank and cam sensor codes may appear.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0373?
-
Read cam sensor B waveform with oscilloscope for missing pulses.
-
Inspect camshaft reluctor for damaged or missing teeth.
-
Check cam sensor B air gap.
-
Verify timing chain alignment marks.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P0373?
- 2010-2020 Toyota Highlander (3.5L V6)
- 2012-2019 Ford Explorer (3.5L V6)
- 2008-2018 Honda Pilot (3.5L V6)
- 2011-2020 Chevrolet Traverse (3.6L V6)
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