P20AF - OBD II Trouble Code

January 31, 2017

Our automotive experts have put together the following information about the P20AF diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P20AF code.

OBD II Fault Code

  • OBD II P20AF

OBD-II Code Powertrain Control Module (PCM) failure is defined as a Reductant Metering Unit Temperature Sensor Circuit High

The heating unit for the Reductant (DEF) system ensures that the DEF fluid does not freeze or crystallize between tank and the injector. The engine computer monitors the temperature of the system using the Reductant Metering Unit Temperature Sensor. If the temperature sensor sends back an implausible signal, code P20AF is stored.

Powertrain Control Module (PCM) failure Symptoms

  • DPF regeneration may not occur

Common Problems That Trigger the P20AF Code

  • Powertrain Control Module (PCM) failure
  • Reductant heating unit temperature sensor failure
  • Wiring issue

About the Author

Brad Kava is an automotive expert at RepairPal, the leading online source of auto repair resources and estimates. With many ASE Master certified mechanics on staff who have decades of experience, RepairPal knows all the fine points of car repair.

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