# Service bulletin 1802821

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: 10220956
- Published by NHTSA: 2022\-09\-26
- Manufacturer's number: 1802821
- Manufacturer's date: 2021\-03\-13
- NHTSA component: POWER TRAIN; ELECTRICAL SYSTEM

## NHTSA's summary

Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation, a technician may find one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: P0524 \- Low oil pressure \(during start up in cold ambient temps\). P249C\-00 \- Excessive Time To Enter Closed Loop Reductant Injection Control. P02E8\-00 \- Diesel Intake Air Flow Position Sensor Circuit Low. P20FB\-00 \- Reductant Pump 2 Control Performance. P065A\-00 \- Generator System Performance. P00AF\-00 \- Turbocharger Boost Control Module "A" Performance. P200A\-00 \- Intake Manifold Runner Performance \- Bank 1. P200B\-00 \- Intake Manifold Runner Performance \- Bank 2. P0106\-00 \- Manifold Absolute Pressure Sensor Performance. Customers may experience the following:Radio may reset during engine idle. Electronic Throttle Control \(ETC\) lamp turns on. After a long cold soak a stumble/hesitation is felt during the first few light accelerations. Turbo Surge in park or neutral and high Idle. The cruise control and speed limited set speed doesn?t match the speedometer. It could be up to 2.5 kpm \(1.5 mph\) difference. Other Software enhancements:Speedometer accuracy improvement\(s\). Cruise control updates. Battery durability improvements in hot ambient temperatures. Improved idle quality during remote start.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10220956-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10220956-9999.pdf)

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

## Components

Electrical system, Transmission and driveline

## Trouble codes named

P00AF, P0106, P02E8, P0524, P065A, P200A, P200B, P20FB, P249C

## Vehicles listed

- 2021 RAM 1500

## Recalls for the same vehicles and component

- [25V298000](/recalls/nhtsa/25V298000.md), 2025-05-08: AIR BAGS; ELECTRICAL SYSTEM:WIRING
- [23V265000](/recalls/nhtsa/23V265000.md), 2023-04-13: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\)

## Other bulletins for the same vehicles and component

- [S2621000004](/bulletins/11038329.md), 2026-10-07, Service bulletin: POWER TRAIN. The Customer May Complain About a Popping Noise, Grinding Noise, or an Intermittent No Reverse or Forward Transmission Engagement. The Tech May Find Damaged and/or Worn Transmission Output Shaft Splines \(850RE Transmission Only\)
- [114072](/bulletins/11036362.md), 2026-08-26, Service bulletin: ELECTRICAL SYSTEM. MOTOR \- WINDOW REGULATOR
- [114073](/bulletins/11036361.md), 2026-08-26, Service bulletin: ELECTRICAL SYSTEM. MOTOR \- WINDOW REGULATOR
- [S2608000033](/bulletins/11035198.md), 2026-07-23, Service bulletin: STRUCTURE:BODY; ELECTRICAL SYSTEM. Cluster Message “To Operate Tailgate Shift to Park” Vehicle is In Park
- [21\-056\-26](/bulletins/11035058.md), 2026-07-18, Service bulletin: POWER TRAIN. Flash: Transmission Control Module \(TCM\) Updates Customers may comment on one or more of the following: SYMPTOM: ● \*\*Harsh or slipping feeling during upshifts \(1st \- 5th\). ● Harsh or slipping feeling during kickdown events under throttle. ● Transmission fluid odor \(burnt smell\).\*\* ● During a 2 \- 3 transmission upshift, the engine is hitting rev limit. ● Hesitation feel during a pedal tip in, while engine is warming up below 1 °C \(30 °F\) ambient temp. This bulletin involves reprogramming the TCM with the latest available software.
- [113069](/bulletins/11034910.md), 2026-07-08, Service bulletin: STRUCTURE:BODY; ELECTRICAL SYSTEM. SWITCH – HEADLAMP
- [113070](/bulletins/11034909.md), 2026-07-08, Service bulletin: ELECTRICAL SYSTEM; STRUCTURE:BODY. SWITCH – HEADLAMP
- [S1623000028 Rev. K](/bulletins/11033975.md), 2026-06-18, Service bulletin: ELECTRICAL SYSTEM; STRUCTURE:BODY. Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
- [S1623000028 REV.I](/bulletins/11033308.md), 2026-06-03, Service bulletin: ELECTRICAL SYSTEM; STRUCTURE:BODY. Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
- [08\-208\-26 REV. A](/bulletins/11032842.md), 2026-05-20, Service bulletin: ELECTRICAL SYSTEM. Radio Message "Power Surge On USB Detected" Customers may comment on the following: ● The radio displays the message: “Power surge on USB hub detected” Fig. 1. NOTE: After the message appears, no USB devices function in the hub \(no charging, no data\). NOTE: Hub operation does not return until the vehicle undergoes a full key cycle.

JSON: [/v1/bulletins/10220956](/v1/bulletins/10220956)

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