P0377

Warning

Timing Reference High Resolution Signal B Too Many Pulses

Severity
Warning
Category
Powertrain
Code Type
Generic OBD-II
Applicable Regions
US, EU, Global

Is it safe to drive?

🟡 Check the vehicle display for drive or charge restrictions and schedule service promptly.

What does P0377 mean?

P-code P0377 means "Timing Reference High Resolution Signal B Too Many Pulses". It is a generic OBD-II diagnostic trouble code (DTC) in the powertrain. A fault has been detected in the timing reference high resolution signal b too many pulses — the control module has logged this condition during self-diagnostics. This warning should be addressed within the next few days to avoid further damage. This code applies to OBD-II compliant electric and hybrid vehicles.

Possible Causes

  • Faulty or failed component in the powertrain
  • Damaged or corroded wiring and electrical connectors
  • Control module software error or firmware fault
  • Poor or missing ground connection at the affected module

Recommended Actions

  1. 1 Avoid aggressive driving and schedule a diagnostic appointment within the next 1–3 days
  2. 2 Scan for all DTCs with an OBD-II scanner — note any related codes stored alongside P0377
  3. 3 Inspect the powertrain component and its wiring for visible damage
  4. 4 Check for water intrusion in connector areas and clean contacts if corroded
  5. 5 Clear the DTC, road-test the vehicle, and re-scan to confirm whether the fault returns
  6. 6 If the fault persists after inspection and clearing, consult an EV-certified technician for component replacement

Related Powertrain fault codes

P0100 Mass or Volume Air Flow Circuit Malfunction P0102 Mass or Volume Air Flow Circuit Low Input P0103 Mass or Volume Air Flow Circuit High Input P0105 Manifold Absolute Pressure/Barometric Pressure Circuit P0107 Manifold Absolute Pressure/Barometric Pressure Circuit P0108 Manifold Absolute Pressure/Barometric Pressure Circuit P0110 IAT Circuit Malfunction P0117 Engine Coolant Temperature Circuit Low Input