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Service bulletin 21-026-14

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 id10139707
Published by NHTSA2018-06-11
Manufacturer's number21-026-14
Manufacturer's date2014-08-27
NHTSA componentPOWER TRAIN; ELECTRICAL SYSTEM

NHTSA's summary

Flash: Transmission Shift Enhancements This bulletin involves flash reprogramming of the Transmission Control Module (TCM) with new software. Some customers may experience any or all of the following transmission shift concerns. 3-2, 2-1 Shift bump on deceleration. Shift quality during hard acceleration. Excessive shifts during cruise control operation. Intermittent delay shift condition. Engine braking improvements during downhill descent. Manual gear selection improvements at higher altitudes. Drivability improvements in 4 low. Hesitation improvements. Inconsistent and/or harsh 1-2, 2-3, 3-4, 4-5 upshifts at moderate throttle. Inconsistent and/or harsh lift-foot upshifts. Inconsistent and/or harsh coasting 3-2, 2-1 downshifts in Hi or Lo range. Ratio fault detection during 1-2 upshift or 8-7 downshift. Grade hunting (repeated shifting while ascending a grade). 8-7-8 shift busyness when approaching max vehicle speed. Undesired gear selection at high altitude. Undesired gear selection when driving downhill (not enough powertrain braking). Time to exit TIP (manual/paddle shift mode) takes too long. Unintended downshifts driving at certain speeds. 4-3 coasting downshift may cause excessive engine noise during engine braking. Shift hanging when vehicle is started cold. Undesired shift toggling in Manual/Paddle Shift mode. Lo range selec-speed control 1-2 shift busyness.

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, Transmission and driveline

Vehicles listed
JEEP GRAND CHEROKEE2014

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

Recalls for the same vehicles and component
18V3320002018-05-17. ELECTRICAL SYSTEM:SOFTWARE; VEHICLE SPEED CONTROL:CRUISE CONTROL; ELECTRICAL SYSTEM:WIRING
20175742017-11-22. Electrical
17V7410002017-11-21. ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR
20173412017-07-10. Electrical
17V4350002017-07-10. ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR
20161842016-04-26. Powertrain
16V2400002016-04-25. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
20144482014-10-09. Electrical
20144462014-10-09. Electrical
14V6340002014-10-08. ELECTRICAL SYSTEM:ALTERNATOR/GENERATOR/REGULATOR

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
S1623000028 Rev. K2026-06-18. Service bulletin. Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
S1623000028 REV.I2026-06-03. Service bulletin. Outside Power Fold Rearview Mirror Noise Or Loose At Pivot. Mirror Contacts Door Window Glass In The Folded Position.
S26230000232026-04-15. Service bulletin. Power Liftgate Inoperative.
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.
S26080000102026-03-13. Service bulletin. Active Diagnostic Trouble Code (DTC) B1A10-00, B1A11-00, B1A12- 00, B1A13-00-, B1A14-00, B1A15-00, B1A16-00, and B1A17-00 in The Radio Frequency Hub (RFH)
91006712025-09-24. Service bulletin. Verify "Z" part number availability. Order a "Z" part number for all Exchange Orders: Warranty, Mopar, Customer pay and Service contract. Order "68" part number for New unsold units only.
S2208000138 REV.B2025-07-09. Service bulletin. Decreased Remote Start And RKE Range. Tire Pressure Sensors Values Are Not Displayed
S1408000384 REV.H2025-01-28. Service bulletin. Start Stop Charging Warning Lamp Illuminated On, Intelligent Battery Sensor (IBS) State of Charge (SOC) Inaccurate, Battery Charging Message, Presence of IBS Related Diagnostic Trouble Codes (DTCs), or Battery Warning Lamp On
1012322024-11-07. Service bulletin. Plate - Planetary
S14080003842024-03-18. Service bulletin. Start Stop Charging Warning Lamp Illuminated On, Intelligent Battery Sensor (IBS) State of Charge (SOC) Inaccurate, Battery Charging Message, Presence of IBS related Diagnostic Trouble Codes (DTCs), or Battery Warning Lamp On