Generic fault code
P037E — Glow plug, sense circuit: signal low
The control unit stores code P037E when it detects this fault: “Glow plug, sense circuit: signal low”.
Indicative severity: MediumElectrical system (12 V, starting and charging)
Reviewed by Daniel Morales, founder of Reprorace SL, on
What does code P037E mean?
The battery, charging and the 12 V system and, on diesels, the glow plugs that help the engine start from cold.
- System
- P · Powertrain
- Area
- Electrical system (12 V, starting and charging) · Car system: Ignition
- Type
- Generic (SAE J2012 / ISO 15031-6): the same meaning on every make
- Indicative severity
- Medium. Diagnose soon: it may raise emissions or consumption, or trigger limp-home mode.
What usually causes code P037E?
- Short circuit to ground
- Loose or corroded connector, backed-out terminals
- Damaged, chafed or pinched wiring
The most likely causes come first. Only a check on the car confirms which one is yours.
What are the symptoms of code P037E?
- Hard starting from cold
- White smoke or a rough engine for the first few seconds
- The glow plug light flashing or staying on
These are the usual symptoms of this kind of fault: not all of them always appear, and sometimes you notice nothing.
Can I keep driving with code P037E?
With care, and not for long. You can take the car to a workshop, ideally without long trips or heavy loads, and without putting it off: fuel use or emissions may rise and the car may go into limp-home mode (less power). If the light flashes, a red warning light comes on, the temperature rises or you notice a loss of power, noises or smoke, stop as soon as it is safe.
This is guidance only: only someone who checks the car can say whether it is safe to drive.
An indicative description of the code's generic meaning. Each manufacturer may give it a different meaning, conditions or tests: always follow its service information and your workshop's advice.
What you can do yourself
For this kind of fault
It shows most in cold weather. Until it is fixed, wait for the glow plug light to go out before starting, and do not keep cranking the engine for long.
Read the code and keep the report: with an ECO-LITE in the OBD socket you see it on your phone or computer, with the data captured when the fault happened.
Look for anything obvious: a loose connector, a disconnected hose, a fuel cap not closed properly or a low fluid level. Do not take apart anything you do not know.
Clear the code only after writing it down or after the repair. Clearing turns the light off, but it also deletes the freeze-frame data and the readiness monitors used at the inspection.
Drive normally for a few days and read the codes again. If the code comes back, the fault is still there: book the workshop and bring the report.
Read your car's fault codes on your phone
With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.
Related codes
- P037DGlow plug, sense circuit: malfunction
- P037FGlow plug, sense circuit: signal high
- P0380Glow plug/heater, circuit A: malfunction
- P0381Glow plug/heater indicator, control circuit open
- P0382Glow plug/heater, circuit B: malfunction
- P0383Glow plug control module 1, control circuit: signal low
P03xx codes: ignition system or misfire
In the glossary
Read more: Remote OBD diagnostics: what it is, how it works and what it can't do