Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P20BF (PCM) - Reductant Heater B Control Circuit Low
2021 Ford Edge SE, 4WDSECTION DTC P20BF (PCM) - Reductant Heater B Control Circuit Low
WARNING: This page is about a different car, the 2020 Ford F-550 Super Duty, 2020 Ford F-450 Super Duty, 2020 Ford F-350 Super Duty, 2020 Ford F-250 Super Duty, and 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
DTC DESCRIPTION P20BF (PCM) - REDUCTANT HEATER B CONTROL CIRCUIT LOW
| Description: | The PCM enables the Glow Plug Control Module (GPCM) during a self-test which monitors the RDHTRC2 circuit. When the GPCM detects that the RDHTRC2 circuit is drawing greater than 15 amps for greater than 250 milliseconds, a short to ground is suspect. The GPCM sends a message to the PCM, which sets this DTC. | ||
| Possible Causes: |
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| Diagnostic Aids: | The presence of this DTC may indicate that the vehicle is operating in derate mode and may experience a loss of power. After repair, the vehicle may still display a system warning message. Drive the vehicle until the system warning message has cleared from the instrument cluster message center. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to PINPOINT TEST RH . | ||
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.