OBD-II code · Powertrain (generic)
P037A Glow Plug/Heater Indicator Control Circuit Low
The driver circuit for the glow plug warning indicator (the dashboard glow lamp) is stuck low — short to ground or stuck-low driver.
Is it safe to drive with P037A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Glow Plug Indicator
Related codes
- P0377Timing Reference High Resolution Signal B Too Few Pulses
- P0378Timing Reference High Resolution Signal B Intermittent/Erratic Pulses
- P0379Timing Reference High Resolution Signal B No Pulses
- P037BGlow Plug/Heater Indicator Control Circuit High
- P037CCold Start Camshaft Profile System Performance
- P037DGlow Plug Sense Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.