2021-2023 Stellantis D Clutch Repair TSB for MIL & DTCs

Owners of various 2021-2023 Stellantis vehicles, including the Jeep Wrangler, may experience a Malfunction Indicator Lamp (MIL) illumination on their instrument cluster. This warning indicates that the vehicle's computer has detected a fault. This condition is often accompanied by specific Diagnostic Trouble Codes (DTCs) pointing to an issue with the transmission's D clutch. Stellantis has released Technical Service Bulletin (TSB) 21-039-24 REV. E to provide a comprehensive repair procedure for this condition.

This bulletin, dated October 10, 2024, is an updated revision (REV. E) that supersedes TSB 21-039-24 REV. D, which was issued on September 25, 2024. All revisions in the current bulletin are highlighted with asterisks and include updated Labor Operation (LOP) descriptions and times. The TSB specifically applies to vehicles equipped with the Eight-Speed Auto 850RE Transmission (Sales Code DFT) that exhibit these symptoms, requiring a D clutch repair.

Symptoms

Vehicle owners will typically observe a "Malfunction Indicator Lamp (MIL) illumination" on their instrument cluster. This warning light indicates that the vehicle's computer has detected a fault. In conjunction with the MIL, one or more specific Diagnostic Trouble Codes (DTCs) will be stored in the vehicle's system, pointing to an issue within the transmission, specifically related to the D clutch.

Fault Codes / DTCs

The TSB identifies the following Diagnostic Trouble Codes (DTCs) that may be present, indicating the need for a D clutch repair:

Code	Description	Module
P0733-00	Gear 3 Shift Incorrect Ratio	Transmission Control Module
P1DA8-00	Incorrect Gear Ratio Clutch A B or D Defective	Transmission Control Module
P1D92-00	Incorrect Gear Ratio - Clutch 4 Defective	Transmission Control Module

Diagnosis / Trigger Conditions

If a customer reports the MIL illumination and any of the listed DTCs are present, technicians are instructed to perform a pressure check of the D clutch circuit. This diagnostic step helps confirm the internal transmission issue. The detailed service procedures for this check are available in the DealerCONNECT/Service Library under "Service Info > 21 - Transmission and Transfer Case / Automatic - 8HP50/850RE / Diagnosis and Testing / Clutch Air Pressure Tests."

Important Warnings for Owners and Technicians

Stellantis highlights several critical warnings and notes within TSB 21-039-24 REV. E to ensure proper repair and prevent further damage:

• Transmission Control Module (TCM) Sensitivity: The Transmission Control Module (TCM), or Transmission Control Module Assembly (TCMA), is extremely sensitive to Electrostatic Discharge (ESD). Technicians must always use a ground strap and follow ESD guidelines for sensitive devices. Failure to do so may result in damage to the TCM/TCMA.
• TCM Adaptation Procedure Required: If the transmission is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the TCM Adaptation Procedure. This procedure is detailed in the DealerCONNECT/Service Library under "Service Info > 08 - Electrical/8E - Electronic Control Modules/ Module, Transmission Control/ Module Programming."
• Unique Transmission Fluid: A unique transmission fluid has been developed for this transmission. This fluid is NOT compatible with ATF+4 or any other current FCA US LLC transmission fluid. Technicians must refer to the "FLUIDS, LUBRICANTS AND GENUINE PARTS" section for specifics on the correct fluid.
• Transmission Positioning: The transmission must be in a vertical position before the main stack is removed to prevent damage to the drums.
• Seal Installation: When installing seals, such as the output shaft seal, it must be installed flush with the case. Driving the seal deeper could damage it and cause a leak.

Repair Procedure Summary

The repair, identified by TSB 21-039-24 REV. E, involves replacing the D clutch within the Eight-Speed Auto 850RE Transmission. The process is extensive and requires significant disassembly and reassembly of the transmission. Here is a summary of the key steps:

1. Initial Checks: Verify the presence of DTCs P0733-00, P1DA8-00, or P1D92-00 and perform a D clutch circuit pressure check. If the D clutch fails the pressure check, the transmission must be removed from the vehicle.
2. Disassembly: This involves removing the torque converter, and depending on the vehicle's drivetrain, the extension housing (for 4WD) or output shaft flange (for 2WD). The transmission oil pan, Hydraulic Impulse Oil Storage (H.I.S.) unit, valve body assembly, Output Speed Sensor, and electrical harness insulator are then carefully removed. Further disassembly includes removing the fluid port, transfer tube, O-rings, input shaft O-ring, and oil pump housing. The B clutch spring damper and park pawl lock rod guide plate are also removed.
3. D Clutch Access: The input/output shaft and P4 annulus drum assembly are removed from the transmission case. The assembly is then placed on a special Press Fixture (Ref. No. 8925-3) for further disassembly. This stage involves removing the B clutch pack, P1 annulus/B clutch hub assembly, thrust bearing, snap rings (using Rings Support Ref. No. 10378), P1 planetary carrier, input shaft with P2 planetary carrier, P2 annulus/P3 sun gear, and finally the D clutch drum. The P4 planetary carrier/output shaft lock ring is also removed, particularly for heavy-duty park systems.
4. Reassembly with New Components: The reassembly process is the reverse of disassembly, incorporating new D clutch repair kit components and seals. This includes installing a NEW P4 planetary carrier/output shaft assembly and lock ring, the D clutch drum, P2 annulus/P3 sun gear, thrust bearings, and the input shaft with P2 planetary carrier. Snap rings, the P1 annulus/B clutch hub, and the B clutch pack are installed, ensuring the transmission remains in a vertical position to prevent drum damage. The B clutch spring damper, new input shaft O-ring, and oil pump housing are reinstalled.
5. Valve Body and External Components: The fluid transfer tube and O-rings, valve body assembly (using alignment pins and ensuring the shift fork lines up properly), Output Speed Sensor (with correct pin alignment), and H.I.S. (if equipped) are reinstalled. The transmission oil pan, new output shaft seal (using a Seal Installer), and extension housing (4WD) or new output flange O-ring and flange (2WD) are then reattached. The torque converter is installed, and for WL 4x4 models, a green o-ring is installed on the output shaft.
6. Finalization: Before installing the transmission back into the vehicle, it must be pre-filled with the unique transmission fluid. After installation, a wiTECH Quick Learn Procedure must be performed, and any remaining DTCs cleared.

Required Tools and Parts

To perform this D clutch repair, technicians will utilize specific tools and parts:

• Special Tools: Guide Sleeve (Ref. No. 10377), Press Fixture (Ref. No. 8925-3), Bearing/Gear (Ref. No. 1130), Rings, Support (Ref. No. 10378), and a Seal Installer.
• D Clutch Repair Kits: Various kits are specified based on the vehicle's drivetrain and model, including part numbers like 68676890AB (4x4 JL, JT, WD, WK), 68676891AB (4x4 WL), 68676887AB (4x4 DS, DT, DX, WS), 68239499AD (AWD LA, LD, LX), 68676892AB (RWD LA, LD, LX), 68676894AB (RWD WD, WK), and 68676893AB (RWD DS, DT, DX, WS).
• Automatic Transmission Fluid: Part number 68218925AB (Qty 10 AR) is required, emphasizing the use of the unique FCA US LLC transmission fluid.

Warranty Information

This D clutch repair is reimbursable within the provisions of the warranty. The labor operation codes and associated times vary by vehicle model and configuration. For instance, the main D clutch replacement can range from 5.4 hours for a 2022 Wagoneer (LOP 21-00-64-95) to 9.7 hours for certain RAM 1500 models (LOP 21-00-64-90). Additional related labor operations, such as for skid plate removal or adaptation procedures, also have specified times.

NHTSA ID: 10257793

What to do if your 2021-2023 Jeep Wrangler has this issue

If your 2021-2023 Stellantis vehicle, such as a Jeep Wrangler, is exhibiting a Malfunction Indicator Lamp (MIL) and has stored DTCs like P0733-00, P1DA8-00, or P1D92-00, it is recommended to schedule an appointment with an authorized Stellantis dealer. The dealer will diagnose the issue, confirm the presence of the relevant DTCs, and perform the D clutch repair as outlined in TSB 21-039-24 REV. E. Ensure to inquire about warranty coverage for the repair.