# Service bulletin 21\-033\-20

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: 10175740
- Published by NHTSA: 2020\-05\-26
- Manufacturer's number: 21\-033\-20
- Manufacturer's date: 2020\-04\-25
- NHTSA component: ELECTRICAL SYSTEM; POWER TRAIN

## NHTSA's summary

Flash: Transmission Control Module \(TCM\) Updates This bulletin involves reprogramming the TCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following DTCs have been set:P1DDE\-00 \- Ignition Run\-Start Input 1\-2 Correlation. P1DF3\-00 \- ECU Not Initialized. P07E4\-00 \- Unable To Engage Park. P0735\-00 \- Gear 5 Shift Incorrect Ratio. The following enhancement is included in this software update:Improvement to the 5\-3\-2 downshift to prevent DTC P0735\-00. Shifter auto\-position correction with ignition in RUN/ACC positions during an AutoPark event.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2020/MC-10175740-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2020/MC-10175740-9999.pdf)

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

## Components

Electrical system, Transmission and driveline

## Trouble codes named

P0735, P07E4, P1DDE, P1DF3

## Vehicles listed

- 2019 RAM 1500

## Recalls for the same vehicles and component

- [25V298000](/recalls/nhtsa/25V298000.md), 2025-05-08: AIR BAGS; ELECTRICAL SYSTEM:WIRING
- [2020401](/recalls/tc/2020401.md), 2020-08-28: Powertrain
- [20V080000](/recalls/nhtsa/20V080000.md), 2020-02-13: POWER TRAIN:TRANSFER CASE \(4\-WHEEL DRIVE\)
- [19V556000](/recalls/nhtsa/19V556000.md), 2019-07-26: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [2019206](/recalls/tc/2019206.md), 2019-04-26: Powertrain
- [19V324000](/recalls/nhtsa/19V324000.md), 2019-04-25: POWER TRAIN:DRIVELINE:DRIVESHAFT
- [19V142000](/recalls/nhtsa/19V142000.md), 2019-02-28: ELECTRICAL SYSTEM:12V/24V/48V BATTERY
- [18V556000](/recalls/nhtsa/18V556000.md), 2018-08-23: POWER TRAIN:AXLE ASSEMBLY
- [18V332000](/recalls/nhtsa/18V332000.md), 2018-05-17: ELECTRICAL SYSTEM:SOFTWARE; VEHICLE SPEED CONTROL:CRUISE CONTROL; ELECTRICAL SYSTEM:WIRING

## 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
- [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.
- [08\-208\-26](/bulletins/11032824.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/10175740](/v1/bulletins/10175740)

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