Service bulletin 18-024-21

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)
Type	Service bulletin
NHTSA id	10190694
Published by NHTSA	2021-04-26
Manufacturer's number	18-024-21
Manufacturer's date	2021-03-06
NHTSA component	POWER TRAIN

NHTSA's summary

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs).P0300 - Multiple Cylinder Misfire.If DTC P0300 is present either alone or along with other DTCs listed within this bulletin the right intake camshaft MUST be replaced along with this software update (only if DTC P0300 is present). Refer to the detailedservice procedures available in DealerConnect>Service Library under: Service Info>09 - Engine, 3.6L / Cylinder Head / Camshaft, Engine / Removal and Installation>Right. If just the software flash was done without the right intake camshaft being replaced the DTC P0300 may reoccur.If DTC P0300 is not present but other DTCs on this list below are present, perform just the software update. P258B - Electronic Vacuum Pump Performance. C1252-92 - Vacuum Pump Control Circuit - Performance Or Incorrect Operation. P0456 - EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification test (SLVT) to determine if a leak is present in the system. P1404 - EGR Close Position Performance. P1206 - Fuel Pump Control Module Open Circuit To Fuel Pump. Upon diagnosing the vehicle the technician may find DTC P1206 set before flashing the vehicle, the correct DTC will now be P025A - Fuel Pump Module Control Circuit Open after the software update.In addition the customer may notice one or more of the following:The Anti-Lock Brake System (ABS) light illuminates. The customer may notice an ability to shift into 1st gear at an unsafe speed(MTX Only). Cluster displays "Autopark Engaged" even when autopark is no longer active.

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

C1252, P025A, P0300, P0456, P1206, P1404, P258B

Vehicles listed
JEEP GLADIATOR	2020

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

Recalls for the same vehicles and component
2023089	2023-02-23. Powertrain
23V116000	2023-02-23. POWER TRAIN:CLUTCH ASSEMBLY
2021035	2021-01-28. Powertrain
21V028000	2021-01-28. POWER TRAIN:CLUTCH ASSEMBLY
2020083	2020-03-03. Powertrain
20V124000	2020-03-03. POWER TRAIN:CLUTCH ASSEMBLY
2019438	2019-08-29. Powertrain
19V636000	2019-08-29. POWER TRAIN:DRIVELINE:DRIVESHAFT

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
S2621000004	2026-10-07. 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)
S2621000003	2026-03-05. 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.
9100627	2025-07-23. 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. C	2025-07-09. 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.
9100570	2025-05-19. Service bulletin. "Transmission Fluid Please note fluid color/condition/odor is NOT an indicator of transmission health and should not be used as the reason for unit replacement. Visible ""glitter"" or debris in the pan does not justify complete unit replacements."
9100534 Rev 1	2025-05-19. Service bulletin. Transmission "Transmission For transmission concerns related to DTCs P0733-00, P1DA8-00, and/or P1D92-00, a repair is available, and transmission replacement is NOT required. Please reference TSB 21-009-25 Rev. A, for details on D-clutch replacement. Please also note, visible ""glitter"" or debris in the pan and fluid color/condition/odor is NOT an indicator of transmission health and should not be used as the reason for unit replacement. Complete unit replacements instead of repairs for these DTCs may be subject to chargeback."
21-009-25 REV. B	2025-04-08. 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."
9100534	2025-03-28. Service bulletin. "Transmission For transmission concerns related to DTCs P0733-00, P1DA8-00, and/or P1D92-00, a repair is available, and transmission replacement is NOT required. Please reference TSB 21-009-25 Rev. A, for details on D-clutch replacement. Please also note, fluid color/condition/odor is NOT an indicator of transmission health and should not be used as the reason for unit replacement. Complete unit replacements instead of repairs for these DTCs may be subject to chargeback."
9100390 Rev 1	2025-03-19. Service bulletin. "D Clutch Repair Kit For transmission concerns related to DTCs P0733-00, P1DA8-00, and/or P1D92-00, a repair is available, and transmission replacement is NOT required. Please reference TSB 21-009-25 Rev. A, for details on D-clutch replacement. Please also note, fluid color/condition/odor is NOT an indicator of transmission health and should not be used as the reason for unit replacement. Complete unit replacements instead of repairs for these DTCs may be subject to chargeback."
S2521000001	2025-02-11. Service bulletin. Clutch Overheat, And/Or Service Transmission Illuminated. Diagnostic Trouble Code (DTC) P08A6 – Gear Lever Position Sensor System – Multiple Sensor Correlation, Set Only In 4Low.