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Service bulletin 21-024-24 REV. A

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 id11001291
Published by NHTSA2024-06-07
Manufacturer's number21-024-24 REV. A
Manufacturer's date2024-05-23
NHTSA componentPOWER TRAIN
Manufacturer's systemTransmission Control Module

NHTSA's summary

"Flash: Transmission Control Module (TCM) Updates **Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC):** ● P0810 - Clutch Position Control Error. Customers may also experience one or more of the following: ● K0 Adaptation routine runs when vehicle stationary and in EV Mode. ● Vehicle loses propulsion capability. ● Service transmission warning light on. NOTE: A key cycle will recover these symptoms. **The following software enhancement is available: ● Modified the P0810 - Clutch Position Control Error set parameters.** **This bulletin involves reprogramming the TCM with the latest available software.** NOTE: **Please be sure that the 04B recall is completed prior to performing this TSB. This TCM software update is covered by the 04B recall if still incomplete.**"

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

Trouble codes named

P0810

Vehicles listed
JEEP WRANGLER 4XE2021 (the catalog's model; the bulletin names a series or trim of it)

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

Recalls for the same vehicles and component
24V5720002024-08-01. POWER TRAIN:MANUAL TRANSMISSION:CONTROL MODULE:SOFTWARE
20230892023-02-23. Powertrain
23V1160002023-02-23. POWER TRAIN:CLUTCH ASSEMBLY
20226722022-11-23. Powertrain
20210352021-01-28. Powertrain
21V0280002021-01-28. POWER TRAIN:CLUTCH ASSEMBLY

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
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)
21-041-26 REV. A2026-07-02. Service bulletin. Transmission Auxiliary Oil Pump Failure Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set **one or more the following Diagnostic Troubles Code (DTCs): ● U0287-00 - Lost Communication With Transmission Fluid Pump Module 1.** ● P0B0D-00 - Electric/Auxiliary Transmission Fluid Pump Motor Control Module. Customers may also comment on the following: ● Vehicle is in limp mode. This bulletin involves replacing the transmission oil pump.
21-041-262026-05-20. Service bulletin. Transmission Auxiliary Oil Pump Failure Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P0B0D-00 - Electric/Auxiliary Transmission Fluid Pump Motor Control Module. Customers may also comment on the following: ● Vehicle is in limp mode This bulletin involves replacing the transmission oil pump.
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.
18-005-26 REV.A2026-03-05. 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): ● P08A6 - Gear Lever Position Sensor System – Multiple Sensor Correlation. (Manual Transmission and NA Only) ● P152F - Engine Hood Switch 2 / Engine Hood Switch 1 Correlation. (NA Only) ● P0300 - Multiple Cylinder Misfire. Customers may also comment on one or more of the following: ● "Service Transmission” message on in the Instrument Panel Cluster (IPC) due to clutch slip detection. (Manual Transmission and NA Only) NOTE: Customers might experience wheel spin or slippage and the PCM could interpreted the wheel spin or slippage as slipping the clutch too much and to avoid clutch damage, the customer may see the message in the IPC. ● Vehicle is in limp home mode.(NA Only) ● Spark knock/detonation sound from the engine at idle. Other software enhancements included: ● Engine oil pump in high pressure mode with cold engine oil to improve valvetrain component reliability. (NA Only) This bulletin involves reprogramming the PCM with the latest available software.
91006842025-10-29. Service bulletin. When servicing/replacing 68415437A$ Transmission, take care to not damage the PIM to P2 harness. Also, when reinstalling the harness, route the harness properly and secure it at all the retention points.
21-038-252025-08-21. Service bulletin. Transmission Auxiliary Oil Pump Failure Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set the following Diagnostic Trouble Code (DTC): ● P0B0D-00 - Electric/Auxiliary Transmission Fluid Pump Motor Control Module. Customers may also comment on the following: ● Vehicle is in limp mode This bulletin involves replacing the transmission oil pump.
91006272025-07-23. Service bulletin. To inform dealers about the 850RE valve body PN: R8348504A connector: the original 16-pin connector included six pins that were not used in this application. To simplify the design, the connector has been optimized and updated to a 10-pin configuration.
21-009-25 REV. C2025-07-09. Service bulletin. 850RE D Clutch Repair Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must have at least 11,265 km (7,000 mi.) and exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0733-00 - Gear 3 Shift Incorrect Ratio. ● P1DA8-00 - Incorrect Gear Ratio Clutch A B or D Defective. ● P1D92-00 - Incorrect Gear Ratio - Clutch 4 Defective. Customers may also comment on one or more of the following: ● Transmission slips when shifting. ● Vehicle will not move in reverse. ● Vehicle will not shift higher than third gear This bulletin involves replacing the D clutch.