Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Glow Plug System Relearn Procedure
Important: Vehicle must be in operating condition before performing this procedure.
The glow plug system type learn is used to identify the correct system type (Federal or California). The scan tool will display Federal, California or Not Learned (Engine Data List). The glow plug system type needs to be relearned when a new calibration has been "flashed" programmed into the powertrain control module (PCM) (it is not necessary to relearn a glow plug system type after a PCM has been replaced, the new PCM has the ability to perform an auto learn when the system is not present (Not Learned will be displayed on the scan tool). If a system type has not been relearned after the PCM has been "flashed" a P0380 will set.
- Turn ON the ignition, with the engine OFF.
- Using the scan tool, select Special Functions, Engine Output Functions and Glow Plug System Learn.
- Activate the Glow Plug System Learn by selecting ON. After the learn function has been preformed Not Learned will be displayed on the scan tool (in this step, the scan tool is clearing the system type).
- Go back to the Special Functions menu on the scan tool and select Glow Plug.
- Activate the Glow Plug system by selecting ON (in this step, the glow plug relay is now sending the identifying (signature) voltage to the PCM).
- The PCM will now be able to identify the correct glow plug system type.
- Clear the DTC P0380.
- Allow the PCM to power down for at least 45 seconds.
- Turn ON the ignition, with the engine OFF. Use the scan tool to verify that DTC P0380 has not reset.
- If DTC P0380 reset, perform the following:
- Check the connections at the glow plug relay.
- Try again to relearn the glow plug system. If the relearn fails again, refer to DTC P0380 (Federal & California) .
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.