# Service bulletin 21\-027\-15 REV\-C

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: 10151743
- Published by NHTSA: 2018\-12\-17
- Manufacturer's number: 21\-027\-15 REV\-C
- Manufacturer's date: 2015\-10\-09
- NHTSA component: POWER TRAIN

## NHTSA's summary

Flash: Transmission Shift Enhancements This bulletin involves reprogramming of the Transmission Control Module \(TCM\) with the latest available software. A small number of customers may experience an erroneous Malfunction Indicator Lamp \(MIL\) Illumination. Upon further investigation, the technician may find a Diagnostic Trouble Code \(DTC\) stored in the TCM memory. In addition, the following TCM calibration improvements are also available for vehicles equipped with the 845RE 8 speed transmission \(Sales Code DFL\). These improvements are listed per engine application. 3.0L Gas Engine \(Sales Code EHD\) ? P1DCD \- TCM monitoring processor performance multiple clutches locked up. ? P1B13 \- Park\-By\-Wire unintended out of park position. ? P0734 \- Gear 4 Shift Incorrect Ratio. ? Improved upshift timing. ? Improved torque converter engagement. ? Improved shift timing during tow mode operation. ? Improved shift points during aggressive driving. ? Calibration improvement to correct bump feel during 2\-1 downshift. ? Improved shift timing while in snow, base, and hill modes. 3.6L Gas Engine \(Sales Code ERB\) ? P1DCD \- TCM monitoring processor performance multiple clutches locked up. ? P1B13 \- Park\-By\-Wire unintended out of park position. ? P0734 \- Gear 4 Shift Incorrect Ratio. ? Improved 4\-3 and 3\-2 downshifts. ? Improved shift timing at higher altitudes. ? Improved shift timing while in sand mode. ? Calibration improvement for multi\-gear downshift timing during passing maneuvers. ? Calibration improvement for intermittent delayed upshift.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2015/MC-10151743-9999.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2015/MC-10151743-0001.pdf)

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

## Components

Transmission and driveline

## Trouble codes named

P0734, P1B13, P1DCD

## Vehicles listed

- 2015 DODGE DURANGO
- 2015 JEEP GRAND CHEROKEE

## Recalls for the same vehicles and component

- [2016184](/recalls/tc/2016184.md), 2016-04-26: Powertrain
- [16V240000](/recalls/nhtsa/16V240000.md), 2016-04-25: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\)

## Other bulletins for the same vehicles and component

- [S2623000023](/bulletins/11031337.md), 2026-04-15, Service bulletin: POWER TRAIN; ELECTRICAL SYSTEM. Power Liftgate Inoperative.
- [S2621000003 REV.A](/bulletins/11030138.md), 2026-03-18, Service bulletin: POWER TRAIN. The vehicle will exhibit a service transmission/check engine warning indicator for the following transmission models: 845RE, 8HP45, 850RE, 8HP50, 8HP70, 8HP75, 8HP75\-PHEV, 8HP75\-LCV, 8HP90, 8HP95. Transmissions may exhibit the following diagnostic codes: P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
- [101232](/bulletins/11010205.md), 2024-11-07, Service bulletin: POWER TRAIN. Plate \- Planetary
- [2104014](/bulletins/10232024.md), 2023-02-21, Service bulletin: POWER TRAIN. 8HP70 Transmission Shift Enhancements
- [2103914](/bulletins/10232023.md), 2023-02-21, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION. Transmission Shift Enhancements
- [2103814](/bulletins/10232022.md), 2023-02-21, Service bulletin: POWER TRAIN. 8HP70 SRT Transmission Shift Enhancements
- [1806714](/bulletins/10232004.md), 2023-02-21, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\); POWER TRAIN; ELECTRICAL SYSTEM. MIL Illumination, P1CF3 Battery Temperature Sensor Out of Range Low
- [1806314](/bulletins/10232000.md), 2023-02-21, Service bulletin: POWER TRAIN; ELECTRICAL SYSTEM. 5.7L Powertrain Diagnostic And System Improvements
- [2103014](/bulletins/10229964.md), 2023-01-17, Service bulletin: EQUIPMENT; POWER TRAIN. Transmission Quick Learn Procedure
- [1807414](/bulletins/10229914.md), 2023-01-17, Service bulletin: POWER TRAIN; ELECTRICAL SYSTEM. Flash: 3.0L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module \(PCM\) with the latest available software. The following software is being released to improve A/C compressor relay duty cycle operation to prevent ignition off battery draw.

JSON: [/v1/bulletins/10151743](/v1/bulletins/10151743)

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