Code Definition

P0380 — Glow Plug/Heater Circuit A Malfunction

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0380

P0380 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0380 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0380 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The powertrain control module (PCM) sets this code when it detects a fault in the glow plug/heater circuit for bank A. This could be due to an open, short, or excessive resistance in the circuit. The PCM monitors the voltage and current flow to ensure proper operation of the glow plugs, which are essential for cold-starting diesel engines. If the expected parameters are not met, the code is triggered.

Quick Facts