OBD Guide
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P037B

Glow Plug/Heater Indicator Control Circuit High

P037B is an OBD-II diagnostic trouble code meaning: Glow Plug/Heater Indicator Control Circuit High. Common causes: short circuit of the lamp control circuit to +12v, malfunction of the glow plug control unit. Estimated repair cost: $11–56.

Severity
✅ Low
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$11–56 (est.)

Symptoms

  • The pre-heating lamp is constantly on or does not go out
  • Check Engine Light Is On
  • Possible difficulties starting a diesel engine in the cold
  • Other symptoms associated with glow plugs, if they are also faulty

Causes

  • Short circuit of the lamp control circuit to +12V
  • Malfunction of the glow plug control unit
  • Damage to instrument panel harness wiring
  • Warm-up lamp relay malfunction
  • ECU malfunction (rare)

How to Fix

  1. Read codes, check for associated glow plug codes (P0380–P0385)
  2. Check the voltage at the lamp control circuit on the dashboard
  3. Inspect the glow plug control unit connector
  4. Check the wiring from the computer to the short-circuit lamp to the positive bus
  5. Check the warm-up lamp control relay
  6. If necessary, replace the spark plug control unit or eliminate the short circuit

Related codes

P0380P0381P0382P0383P0384P0385

Error P037B by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P037B code mean?

P037B is an OBD-II diagnostic trouble code that indicates: Glow Plug/Heater Indicator Control Circuit High

What causes a P037B error code?

The most common causes of P037B include: Short circuit of the lamp control circuit to +12V; Malfunction of the glow plug control unit; Damage to instrument panel harness wiring; Warm-up lamp relay malfunction.

How do I fix a P037B diagnostic trouble code?

To fix P037B: Read codes, check for associated glow plug codes (P0380–P0385). Check the voltage at the lamp control circuit on the dashboard. Inspect the glow plug control unit connector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P037B?

Yes, but get it checked soon

How much does it cost to fix P037B?

The estimated repair cost for P037B is $11–56. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat