What does code P1399 mean?

Q: What does code P1399 mean?

Glow Plug Circuit High Side High Input. This code means the glow plug control module has detected an abnormally high voltage on the high side of the glow plug circuit, typically a short to battery voltage or a fault inside the module itself. The powertrain control module (PCM) sets P1399 when the feedback signal from the glow plug circuit exceeds the expected range during the self-test or while the glow plugs are commanded on.

DTC codes / Ford codes / P1399

P1399 · FordGlow Plug Circuit High Side High Input

This code means the glow plug control module has detected an abnormally high voltage on the high side of the glow plug circuit, typically a short to battery voltage or a fault inside the module itself. The powertrain control module (PCM) sets P1399 when the feedback signal from the glow plug circuit exceeds the expected range during the self-test or while the glow plugs are commanded on.

SystemPowertrain

Code typeFord specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.