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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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10216162
Published by NHTSA2022-07-25
Manufacturer's number21-027-15 REV. C
Manufacturer's date2015-10-09
NHTSA componentELECTRICAL SYSTEM; ENGINE; POWER TRAIN; EQUIPMENT ADAPTIVE/MOBILITY

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

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Engine, Equipment and accessories, Transmission and driveline

Trouble codes named

P0734, P1B13, P1DCD

Vehicles listed
DODGE DURANGO2015
JEEP GRAND CHEROKEE2015

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20233382023-06-08. Engine
23V4110002023-06-08. ENGINE AND ENGINE COOLING
20205442020-11-12. Engine
20V6990002020-11-12. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE)
20203712020-08-13. Engine
20V4750002020-08-13. ENGINE AND ENGINE COOLING:ENGINE:DIESEL
20182692018-05-17. Engine
18V3320002018-05-17. ELECTRICAL SYSTEM:SOFTWARE; VEHICLE SPEED CONTROL:CRUISE CONTROL; ELECTRICAL SYSTEM:WIRING
20161842016-04-26. Powertrain
16V2400002016-04-25. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
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S26230000232026-04-15. Service bulletin. Power Liftgate Inoperative.
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18-044-262026-03-25. Service bulletin. Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0111-00 - Intake Air Temperature Sensor 1 Circuit Range Performance Bank 1. (In Active or Stored status) ● P0071-00 - Ambient Air Temperature Sensor Performance. (In Active or Stored status) ● P0072-00 - Ambient Air Temperature Sensor Circuit "A" Low. (In Active or Stored status) ● P0073-00 - Ambient Air Temperature Sensor Circuit "A" High. (In Active or Stored status) ● P0011-00 - Bank 1 Camshaft 1 Position Timing Over Advanced Or. (In Active or Stored status) ● P25E4-00 - B Camshaft Position - Unable To Achieve Locked Position Bank 1. (In Active or Stored status) ● P05BD-00 - Stop-Start Mode Switch Range/Performance. (In Active or Stored status) ● P0116-00 - Engine Coolant Temperature Sensor 1 Performance. (In Active or Stored status) ● P062B-00 - Internal Control Module Fuel Injector Control Performance. (In Active or Stored status) ● P0604-00 - Internal Control Module Random Access Memory Ram Error. (In Active or Stored status) ● P060C-00 - Internal Control Module Main Processor Performance. (In Active or Stored status)** ● P018B-00 - Fuel Pressure Sensor "B" Circuit Range/performance. **(In Active or Stored status)** ● P1CEA-00 - Boost Side EVAP Purge System Performance. **(In Active or Stored status)** ● P06DD-00 - Engine Oil Pressure Control Circuit Performance/Stuck Off. **(In Active or Stored status)** ● P00C6-00 - Fuel Rail Pressure Too Low - Engine Cranking. **(In Active or Stored status)** ● P0300-00 - Multiple Cylinder Misfire. **(In Active or Stored status)** Customers may also experience one or more of the following: ● **Oil Level High Warning in the Instrument Panel Cluster (IPC).** ● Fully Autonomous Parking Assist (FAPA) is not deactivated when accelerator pedal is pressed. ● Vehicle is not heating up fast enough at freezi
S2621000003 REV.A2026-03-18. Service bulletin. 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.
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