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P037A Powertrain

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.

Affected components

  • Glow plug indicator

Common causes

  • High likelihood: Short to ground
  • Low likelihood: Connector pins corroded - high contact resistance
  • Low likelihood: Harness chafing through insulation

Possible 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

Diagnostic notes

  • The malfunction indicator lamp may illuminate

Sources

Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.

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