P0380 Glow Plug/Heater Circuit A Malfunction

P0380 points to a glow plug or heater circuit A malfunction. It is common on diesel applications where cold-start heating is monitored by the control system.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System
Ignition / Misfire
Scope
iso-sae-controlled-p0
Standard
SAE J2012 / ISO 15031-6
Source
legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace all glow plugs automatically; controller, power supply, wiring, and individual plug faults need to be separated.

Useful checks before replacing parts

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and fault area. They may share the same verification status as the source database.