# Service bulletin 08\-083\-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: 10181618
- Published by NHTSA: 2020\-10\-26
- Manufacturer's number: 08\-083\-20
- Manufacturer's date: 2020\-09\-18
- NHTSA component: ELECTRICAL SYSTEM; POWER TRAIN

## NHTSA's summary

Flash: Drivetrain Control Module \(DTCM\) Diagnostic and System Improvements This bulletin involves reprogramming the DTCM with the latest available software. The technician may find one or more of the following DTCs: U1440 \- Implausible Transfer Case Ratio High Received. U0403\-00 \- Implausible Data Received From Tcase. C1403\-92 \- Transfer Case Range Position Sensor\-Performance Or Incorrect Operation. If only DTC C1403 is present, follow normal diagnostic procedures before updating the DTCM.In addition the customer may describe one or more of the following: Traction Control System light is illuminated. A driveline bump can be heard/felt occasionally when the driver is steady on the throttle at about 20\-30% on a flat road while in 4WDAUTO. An excessive electric motor clicking sound from the middle of the vehicle/transfer case area, when on and off the throttle. An excessive electric motor clicking sound with steering wheel movement, most notable in parking lot or low speed maneuvering. A ?Service 4WD? message/fault without commanding a transfer case shift.If only the ?Service 4WD? message/fault is displayed inthe Instrument Panel Cluster \(IPC\) and no other symptom/conditions are present, follow normal diagnostic procedures before updating theDTCM. The blinking of the ?4WD Low? and ?4WD High? indicator lights at the same time, on the transfer case selector switch.If both 4WD indicator lights on the transfer case selector switch are blinking and no other symptom/conditions are present,follow normal diagnostic procedures before updating the DTCM. During highway/freeway speeds, a bump in the driveline may be felt. This could also be described as a harsh transmission shift.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2020/MC-10181618-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2020/MC-10181618-9999.pdf)

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

## Components

Electrical system, Transmission and driveline

## Trouble codes named

C1403, U0403, U1440

## Vehicles listed

- 2019 to 2020 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/10181618](/v1/bulletins/10181618)

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