What are the common causes of P20C2?

A reductant heater C element that reads outside its expected range. Corrosion or damage in the heater C control circuit. A failed reductant heater control module. Incorrect heater C installation or calibration.

Read the reductant heater C control circuit on a scan tool. Compare heater C current draw to the expected value. Test the heater C wiring and connector. Replace reductant heater C if current draw is out of range. Clear the code and retest.

P20C2

Reductant Heater C Control Circuit Performance

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P20C2 means Reductant Heater C Control Circuit Performance.

Check these first

A reductant heater C element that reads outside its expected range
Corrosion or damage in the heater C control circuit
A failed reductant heater control module
Incorrect heater C installation or calibration

What to do next

Read the reductant heater C control circuit on a scan tool
Compare heater C current draw to the expected value
Test the heater C wiring and connector
Replace reductant heater C if current draw is out of range
Clear the code and retest

Look up another code

Code or symptom

Enter a full code or a symptom. Press / to search. How to read a code

Type a code above, or start from a symptom or a common code.

Updated

Generic SAE J2012 definition. Last updated 2026-10-10.