P037DGlow Plug Sense Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- To check the glow plugs, the engine module reads back the voltage or current of the glow plug supply through a sense circuit – CARB requires glow plug circuits to be monitored for correct current and voltage drop, and from model year 2010 the failure of a single plug to be detected. In the J2012 scheme P037D is the general code for this sense circuit, P037E and P037F its low and high counterparts. None of the manufacturer documents available to us uses P037D: GM's 2016/2018 diesels use only P037E/P037F, Ford 2023 its own glow plug codes (P0671 ff, P064C) and Saab reports the feedback of its glow plug control module as P0380/P0382. The description therefore follows CARB and the GM sister codes. Typically glow plug monitoring is inactive; glowing itself can work normally.
- What you may notice
- Check engine light or glow plug light on
- Possibly poor cold start if the cause also affects the glow plug supply
- Further glow plug codes stored
- Likely causes
- LikelySense wire open or high resistance, connector corroded
- PossibleGlow relay or glow plug control module giving an implausible feedback
- PossibleFuse or fusible link of the glow plug supply blown
- RareEngine module internal
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.