P037E

Glow Plug Sense Circuit Low

Q: Is it safe to drive with P037E?

Yes, once the engine is running. Glow plugs mainly assist cold starting, so the concern is hard starts and rough cold idle rather than driving safety.

Q: Can I just clear P037E?

It will return the next time the ECM checks the glow plug circuit. Fix the plug or wiring first, then clear it.

Diesel glow plug / cold start Generic OBD-II High

What it means

P037E is a diesel code meaning the glow plug sense circuit is reading a voltage that is too low. Glow plugs pre-heat the combustion chambers to help a cold diesel start, so this fault mostly shows up as hard cold starting, rough running just after start-up, and cold-start smoke — the engine typically runs fine once it warms up.

High

Can I keep driving? The engine runs normally once warm; the main effect is hard cold starting and rough cold running, so it's a cold-weather concern rather than a breakdown risk.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine (or glow plug) light on
Hard starting when the engine is cold
Rough idle and misfire just after a cold start
White or grey smoke on cold start-up

Common causes

Most likely first

Failed glow plug (open or low resistance)Likely
Open or shorted glow plug wiring/harnessCommon
Poor or corroded connection at the glow plug or moduleCommon
Faulty glow plug control moduleLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and identify which glow plug circuit is flagged.
Inspect the glow plug harness and connectors for damage or corrosion.
Measure each glow plug's resistance and compare against spec.
Check the glow plug control module supply, ground, and control signals.
Replace the faulty glow plug or module; clear and re-test.

FAQ

Quick answers

Is it safe to drive with P037E?+

Yes, once the engine is running. Glow plugs mainly assist cold starting, so the concern is hard starts and rough cold idle rather than driving safety.

Can I just clear P037E?+

It will return the next time the ECM checks the glow plug circuit. Fix the plug or wiring first, then clear it.

Read & clear P037E yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX