# Service bulletin 18\-034\-21 REV. A

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10204384
- Published by NHTSA: 2021\-12\-13
- Manufacturer's number: 18\-034\-21 REV. A
- Manufacturer's date: 2021\-11\-10
- NHTSA component: FUEL SYSTEM, GASOLINE; BACK OVER PREVENTION; FUEL SYSTEM, DIESEL

## NHTSA's summary

P203E and P203F Additional Diagnostic Information This bulletin provides additional information regarding diagnosing Diesel Exhaust Fluid \(DEF\) issue in extreme cold weather. Diagnostic Trouble Codes \(DTCs\) P203E \- Reductant Level Sensor 1 Circuit Intermittent and/or P203F \- Reductant Level Too Low set.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10204384-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10204384-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Driver assistance, Fuel system, Backup camera

## Trouble codes named

P203E, P203F

## Vehicles listed

- 2019 to 2022 RAM 2500
- 2019 to 2022 RAM 3500
- 2019 to 2022 RAM 4500

## Recalls for the same vehicles and component

- [24V436000](/recalls/nhtsa/24V436000.md), 2024-06-13: BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
- [23V654000](/recalls/nhtsa/23V654000.md), 2023-09-28: BACK OVER PREVENTION:DISPLAY FUNCTION
- [22V407000](/recalls/nhtsa/22V407000.md), 2022-06-09: BACK OVER PREVENTION:DISPLAY FUNCTION
- [20V191000](/recalls/nhtsa/20V191000.md), 2020-09-10: BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

## Other bulletins for the same vehicles and component

- [103289](/bulletins/11014887.md), 2025-03-04, Service bulletin: BACK OVER PREVENTION: WARNINGS; LANE DEPARTURE: BLIND SPOT DETECTION. CAMERA \- REAR VIEW
- [S2208000045 REV.B](/bulletins/11011774.md), 2024-12-11, Service bulletin: BACK OVER PREVENTION: REARVIEW SYSTEM BRAKING. Backup Camera Poor Image Quality Inspection
- [1800824](/bulletins/10251873.md), 2024-03-18, Service bulletin: ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; EQUIPMENT; PARKING BRAKE; BACK OVER PREVENTION; FUEL SYSTEM, GASOLINE; SERVICE BRAKES, HYDRAULIC; FUEL SYSTEM, DIESEL; EXTERIOR LIGHTING; POWER TRAIN; ELECTRONIC STABILITY CONTROL:AUTOMATIC \(ASC\). Flash: Powertrain Control Module \(PCM\) Updates Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00 \- Idle Control System RPM \- Lower Than Expected.P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire. P0302\-00 \- Cylinder 2 Misfire. P0303\-00 \- Cylinder 3 Misfire. P0304\-00 \- Cylinder 4 Misfire. P0305\-00 \- Cylinder 5 Misfire. P0306\-00 \- Cylinder 6 Misfire. P0299\-00 \- Turbocharger Underboost. P1D73\-00 \- AGS Performance. P0626 \- Generator Field Control Circuit High. P218F \- Reductant No Flow Detected. P2002 \- Diesel Particulate Filter Efficiency Below Threshold. P24A5 \- EGR Cooler Bypass Bank 1 Control Stuck. P0191 \- Fuel Rail Pressure Sensor Circuit Performance. P0461 \- Fuel Level Sensor 1 Performance. P0401 \- EGR System Performance. P20EE \- SCR NOx Catalyst Efficiency Below Threshold \- Bank 1. P061A \- Level 2 Torque Performance. P061B \- Internal Control Module Torque Calculation Performance. P061E \- Internal Control Module Brake Signal Performance. P062C \- ETC Level 2 MPH Performance. P0106 \- Manifold Absolute Pressure Sensor Performance \(In extreme cold ambient temperatures\). P0116 \- Engine Coolant Temperature Sensor Performance. P0420 \- Catalyst System Efficiency Bank 1. P1507 \- Crankcase Filter Restriction. P203F \- Reductant Level Too Low. P226C \- Turbocharger Boost Control ?A? Slow Response \(In extreme cold ambient temperatures\). P2579 \- Turbocharger Speed Sensor Circuit. U0101 \- Lost Communication with TCM. U02A3 \- Lost of Communication with PM Sensor. U3017 \- Control Module Timer/Clock Performance. Customers may also experience one or more of the following Power
- [1800724](/bulletins/10251872.md), 2024-03-18, Service bulletin: POWER TRAIN; ELECTRONIC STABILITY CONTROL:AUTOMATIC \(ASC\); BACK OVER PREVENTION; EXTERIOR LIGHTING; ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; SERVICE BRAKES, HYDRAULIC; FUEL SYSTEM, GASOLINE; EQUIPMENT; FUEL SYSTEM, DIESEL; PARKING BRAKE. Flash: Powertrain Control Module \(PCM\) Updates Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0506\-00 \- Idle Control System RPM \- Lower Than Expected. P0607\-00 \- ECU Internal Performance. P20E8\-00 \- Reductant Pressure Too Low. P0301\-00 \- Cylinder 1 Misfire. P0302\-00 \- Cylinder 2 Misfire. P0303\-00 \- Cylinder 3 Misfire. P0304\-00 \- Cylinder 4 Misfire. P0305\-00 \- Cylinder 5 Misfire. P0306\-00 \- Cylinder 6 Misfire. P0299\-00 \- Turbocharger Underboost. P1D73\-00 \- AGS Performance. P0626 \- Generator Field Control Circuit High. P218F \- Reductant No Flow Detected. P2002 \- Diesel Particulate Filter Efficiency Below Threshold. P24A5 \- EGR Cooler Bypass Bank 1 Control Stuck. P0191 \- Fuel Rail Pressure Sensor Circuit Performance. P0461 \- Fuel Level Sensor 1 Performance. P0401 \- EGR System Performance. P20EE \- SCR NOx Catalyst Efficiency Below Threshold \- Bank 1. P061A \- Level 2 Torque Performance. P061B \- Internal Control Module Torque Calculation Performance. P061E \- Internal Control Module Brake Signal Performance. P062C \- ETC Level 2 MPH Performance. P0106 \- Manifold Absolute Pressure Sensor Performance \(In extreme cold ambient temperatures\). P0116 \- Engine Coolant Temperature Sensor Performance. P0420 \- Catalyst System Efficiency Bank 1. P1507 \- Crankcase Filter Restriction. P203F \- Reductant Level Too Low. P226C \- Turbocharger Boost Control ?A? Slow Response \(In extreme cold ambient temperatures\). P2579 \- Turbocharger Speed Sensor Circuit. U0101 \- Lost Communication with TCM. U02A3 \- Lost of Communication with PM Sensor. U3017 \- Control Module Timer/Clock Performance.
- [0820323](/bulletins/10248947.md), 2024-01-16, Service bulletin: AIR BAGS; BACK OVER PREVENTION. Radio Over The Air Update to T25.48 Software Version The customer may experience one or more of the following: ? Ambient Light Setting inoperable. ? Radio reset \(Rearview camera functions normally\). ? Voice Recognition \(VR\) inoperable. ? Audio sources inoperable. ? Wireless CarPlay® inoperable. ? Setting preferences not saved on correct profile. ? Audio loss. This bulletin provides information regarding the latest Firmware Over The Air \(FOTA\) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from S26.17 to T25.48. NOTE: The National campaign for this FOTA update launched July 17, 2023.
- [0821223](/bulletins/10248599.md), 2024-01-08, Service bulletin: BACK OVER PREVENTION; EQUIPMENT:ELECTRICAL. Radio Over The Air Update From S26.17 and T25.48 to T25.51 Software Version Customer may experience one or more of the following: ? Missing Side Camera and Trailer View SoftKeys. ? Ambient Light Setting inoperable. ? Radio reset \(Rearview camera functions normally\). ? Voice Recognition \(VR\) inoperable. ? Audio sources inoperable. ? Wireless CarPlayT inoperable. ? Setting preferences not saved on correct profile. ? Audio loss. This bulletin provides information regarding the latest Firmware Over The Air \(FOTA\) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from S26.17 and T25.48 to T25.51. NOTE: The National campaign for this FOTA update is estimated to be launched on September 29, 2023.
- [0806423](/bulletins/10248049.md), 2024-01-02, Service bulletin: BACK OVER PREVENTION:SOFTWARE. Radio Over The Air Updating to QR40.12 Software Version Mobile Wi\-Fi inoperative upon start up. ? Hotspot gives 9No Internet9 connection message on phone, when trying to connect to a device. This bulletin provides information regarding the latest Firmware Over The Air \(FOTA\) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from QR39.7 to QR40.12. NOTE: National launch for this FOTA update is expected to begin March 10, 2023. DISCUSSION: Vehicles sold in the U.S. and Canada can now receive software updates ?over\-the\-air?. Updates to software will occur in a phased roll\-out. The software is updated through the built\-in cellular modem in the radio.
- [0804423](/bulletins/10248019.md), 2024-01-02, Service bulletin: STEERING; TRAILER HITCHES; SERVICE BRAKES; BACK OVER PREVENTION; ELECTRICAL SYSTEM; WHEELS. Radio Over The Air S24.13 and S24.18 Updating to S26.17 Software Version Customers may experience one or more of the following: ? \*\*Blank screen \(Rear view camera is not affected and will still function normally\).\*\* ? Battery drain. ? Radio resets \(Rear view camera will still function normally\). ? Wireless connectivity device disconnect. ? CarPlayT icon does not appear in device manager. ? Climate icon missing. ? Audio disruptions. ? SXMT inoperative. ? Audio muted. ? Passenger screen blank. ? Passenger screen apps missing. ? Missing profiles icon. ? Instrument Panel Cluster \(IPC\) displays incorrect audio source. ? Radio is slow to respond. ? Trailer tire pressure configurations deleted. ? Steering wheel controls skipping SXMT channels. ? Recent calls not displayed. ? Phone audio playing with ignition off. The following improvements are also included with this update: ? Apple CarPlayT and Android AutoT improvements. ? Voice Recognition \(VR\) command improvements. ? Uconnect phone improvements. ? FOTA improvements. ? Passenger screen camera app improvements. ? Icon size/layout improvements. This bulletin provides information regarding the latest Firmware Over The Air \(FOTA\) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from S24.13 or S24.18 to S26.17. NOTE: The national launch for the FOTA is expected to begin November 25, 2022.
- [0804523](/bulletins/10248014.md), 2024-01-02, Service bulletin: BACK OVER PREVENTION:SOFTWARE. Radio Over The Air Updating to 34.42 Software Version ? Mobile Wi\-Fi inoperative upon start up. ? Hotspot gives 9No Internet9 connection message on phone when trying to connect to a device. This bulletin provides information regarding the latest Firmware Over The Air \(FOTA\) update and provides the service technician an overview of the steps a customer will need to take to complete the update. The radio software will be updated from 34.4 to 34.42.
- [1801823](/bulletins/10248008.md), 2024-01-02, Service bulletin: BACK OVER PREVENTION; ELECTRICAL SYSTEM. Flash: Powertrain Control Module \(PCM\) Updates Customer or technician may experience the following: ? \*\*Power Take Off \(PTO\) disable to high engine oil temperature \(DD and DP Cab Chassis only\)\*\*. ? Customer may complain of slow PTO idle ramp up. ? Message will appear ?Hot Oil? and exit high idle or PTO mode, when in high idle or PTO mode and running between 10\-30 minutes \(no load\). ? High frequency exhaust noise at idle after cold start. This bulletin involves reprogramming the PCM with the latest available software.

JSON: [/v1/bulletins/10204384](/v1/bulletins/10204384)

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