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Service bulletin 21-049-26

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 id11033870
Published by NHTSA2026-06-16
Manufacturer's number21-049-26
Manufacturer's date2026-06-04
NHTSA componentPOWER TRAIN

NHTSA's summary

Flash: Transmission Control Module (TCM) Updates Customers may experience one or more of the following: ● Intermittently during low‑speed parking maneuvers when the driver moves from Drive (D) to Reverse (R) at the exact moment the Engine Stop/Start (ESS) system shuts the engine off. ● When the timing aligns, the engine will not automatically restart, and the Instrument Panel Cluster (IPC) displays a shift to park to start reated message. ● NOTE: The behavior results from safety logic that prevents the PCM from restarting the engine while the transmission is in an engaged gear. NOTE: No Diagnostic Trouble Codes (DTCs) or Malfunction Indicator Lamp (MIL) are set because the system is functioning as designed. NOTE: This may appear as an ESS stall, but it is actually a controlled inhibit, not a malfunction. NOTE: The condition is difficult to reproduce due to the timing window required. This bulletin involves inspecting and possibly reprogramming the PCM and Transmission Control Module (TCM) with the latest available software.

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

Transmission and driveline

Vehicles listed
JEEP GRAND CHEROKEE2026
JEEP GRAND CHEROKEE L2026

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

Other bulletins for the same vehicles and component
S26210000042026-10-07. Service bulletin. 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)
08-289-26 REV. A2026-08-06. Service bulletin. Transmission Control Module (TCM) Diagnostic N/A - This bulletin was released in error. SYMPTOM:
08-289-262026-07-29. Service bulletin. Transmission Control Module (TCM) Diagnostic Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following DTCs: ● P2797-00 - Auxiliary Transmission Fluid Pump Performance ● P1625-00 - Park Pawl System Failure NOTE: Park system still functions, no impact to park engagement. NOTE: Vehicle will not experience unintended movement. Customers may also experience one or more of the following: ● Vehicle no start due to battery discharge. ● 'Start/stop inop' message. ● 'Service Transmission' message on in Instrument Panel Cluster (IPC).
21-053-262026-07-08. Service bulletin. Service Transmission Message Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set the following Diagnostic Trouble Code (DTC): ● P2797-00 - Auxiliary Transmission Fluid Pump Performance. Customers may also comment on the following: ● Engine Stop-Start (ESS) does not operate. ● "Service Transmission" message displayed in the Instrument Panel Cluster (IPC). This bulletin involves inspecting and possibly replacing the transmission oil pump motor.
18-058-262026-06-16. Service bulletin. Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one of the following Diagnostic Trouble Codes (DTCs): ● P1CEA - Boost Side Evap Purge System Performance. ● P0300-00 - Random/Multiple Cylinder Misfire Detected ● P0301-00 - Cylinder 1 Misfire ● P0302-00 - Cylinder 2 Misfire ● P0303-00 - Cylinder 3 Misfire ● P0304-00 - Cylinder 4 Misfire Customers may also experience one or more of the following: ● Engine RPM fluctuations at low vehicle speeds after extended idling. ● An ignition-off draw or battery drain condition. ● Sluggish engine performance and misfires. ● Engine knocking when the accelerator is pressed hard or quickly This bulletin involves inspecting and possibly reprogramming the PCM and Transmission Control Module (TCM) with the latest available software.
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.
S26210000032026-03-05. Service bulletin. Service transmission/check engine warning indicator for the 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV transmissions that have fault codes P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
S2521000004 REV.B2026-01-21. Service bulletin. The customer is experiencing a clicking or pop noise from the steering knuckle and bearing area during turns while driving.
1090112025-12-23. Service bulletin. VALVE BODY & CONTROL UNIT – TRANSMISSION
S25210000052025-12-23. Service bulletin. The customer states the ABS and Traction Control warning comes on. Vehicle sets wheel speed BSCM/ABS fault codes.