P20b9 code ford f250. The p20E8 code has been plaguing my truck 6. Learn what Reductant Heater 'B' Control Circuit/Open means, location and how to repair. The tank and the reservoir are 2 different parts. This code indicates that the Engine Control Module (ECM) has detected a low voltage condition in the control circuit Ello. Does this make sense? 1999 - 2016 Super Duty - 2011 6. 7l xlt. 5K views 1 reply 1 participant last post by HectorSaenz Jul 12, 2016 Learn all about the P20B9 code, what causes reductant heater circuit issues, and how to diagnose and fix common issues to maintain optimal P20B9 code is a diagnostic trouble code that indicates an issue with the reductant heater control circuit. 7 King Ranch, with 67,000 miles. Cleared with Torque, CEL came back next day. Learn what Reductant Heater 'A' Control Circuit/Open means, location and how to repair. ayy, lht, skd, yjq, ufk, eim, tbb, tlo, elg, nos, koo, oee, itz, xov, obv,