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P21C4 ← What does this code mean?7 Results
RAM · 2025-05-23
Module, Urea Pump/Level: HD 6.7L (ETL/ETN/ETM) with Mil On P21C4-00 (Reductant Line Heater Relay Control Circuit High / U11C1-00 (Reductant Control Module Received Implausible Data From ECM/PCM), do not replace the DEF Pump. Follow TSB's released and appropriate Service Diagnostics.
RAM · 2025-03-28
"6 CONTROL UNIT, Diesel Exhaust Customer complaints with malfunction light illuminated on 2019 thru 2024 MY DJ / D2 / DD / DP vehicles with 6.7L (ETL / ETM / ETN) built on or before October 15,2024 and exhibiting DTCs P21C4-00 (Reductant Line Heater Relay Control Circuit High) and / or U11C1-00 (Reductant Control Module received implausible Data from ECM / PCM). These DTCs will occur after installation of service DCU 68458603AB. Do not replace parts until after the TSB 25-008-24 is performed. If the DTC(s) continue to set, then follow the Service Diagnostics for the applicable DTC."
RAM · 2025-03-10
Malfunction Indicator Lamp (MIL) Illumination, Diagnostic Trouble Codes (DTCs) P21C4 – (Diesel Exhaust Fluid) Reductant Line Heater Control Circuit High, and U11C1 – Reductant Control Module Received Implausible Data From ECM/PCM, Set
RAM · 2024-11-14
"Flash: Diesel Exhaust Fluid (DEF) Dosing Control Unit (DCU) Update Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P21C4-00 - Reductant Line Heater Relay Control Circuit High. ● U11C1-00 - Reductant Control Module Received Implausible Data From ECM/PCM. These DTCs will occur after installation of service DCU 68458603AB. This bulletin involves reprogramming the DCU with the latest available software."
RAM · 2020-08-07
Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module (ECM) / Powertrain Control Module (PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have been set:P2463-00 - Diesel Particulate Filter Restriction - Soot Accumulation Bank 1. P242F-00 - Diesel Particulate Filter Restriction - Ash Accumulation. P1D73-00 - AGS Performance. P0299-00 - Turbocharger Underboost(Additional Improvement for D2 ETM Only). P1451-00 - Diesel Particulate Filter System Performance. P0421-00 - Catalyst 1 Efficiency Below Threshold Bank 1. P24A5-00 - EGR Cooler Bypass Bank 1 Control…
RAM · 2020-08-07
Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module (ECM) / Powertrain Control Module (PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have been set:P2463-00 - Diesel Particulate Filter Restriction - Soot Accumulation Bank 1. P242F-00 - Diesel Particulate Filter Restriction - Ash Accumulation. P1D73-00 - AGS Performance. P0299-00 - Turbocharger Underboost(Additional Improvement for D2 ETM Only). P1451-00 - Diesel Particulate Filter System Performance. P0421-00 - Catalyst 1 Efficiency Below Threshold Bank 1. P24A5-00 - EGR Cooler Bypass Bank 1 Control…
RAM · 2019-10-22
Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have been set: P0421-00 - Catalyst 1 Efficiency Below Threshold Bank 1. P1451-00 - Diesel Particulate Filter System Performance. P24A5-00 - EGR Cooler Bypass Bank 1 Control Stuck. P21C4-00 - Reductant Line Heater Relay Control Circuit High. P1D73-00 - AGS Performance. P2560-00 - Engine Coolant Level Low. P2201-00 - Aftertreatment NOX Sensor Circuit Performance - Bank 1 Sensor 1. P0604-00 - Internal Control Module Ram.…