Code result

P248A

Reductant Heater A Sense Circuit Low

Moderate severity

What it means

Reductant Heater A Sense Circuit Low: the signal voltage is below the expected range. The reductant (DEF/AdBlue) heater keeps the urea fluid from freezing; a fault can impair SCR dosing in cold conditions.

Is it safe to drive?

Use caution

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

  • Sense line shorted to ground

    high

    One of the most commonly reported causes for this code — check this first.

  • Connector pins corroded - high contact resistance

    low

    Less common, but worth ruling out after the more likely causes.

  • Harness chafing through insulation

    low

    Less common, but worth ruling out after the more likely causes.

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