Technical Service Bulletin (TSB)
Flash: Transmission Control Module (TCM) Updates
REFERENCE:

VEHICLES
AFFECTED:

TSB: 21-028-23
GROUP: 21 - Transmission and Transfer
Case

Date:

November 1, 2023

2022 (WL) Jeep Grand Cherokee
This bulletin applies to vehicles equipped with a 2.0L I4 DOHC DI
Turbo PHEV Engine (Sales Code ECX) with 8-Spd Auto 8P75 PHEV
Transmission (Sales Code DFY).

CUSTOMER
SYMPTOM:

Customer may experience the following:

CAUSE:

TCM Software

REVISION:

–

MARKET APPLICABILITY:

NA

MEA

SA

IAP

EE

CH

• Shifts rough occasionally when coming down to a stop.
• Shifts rough occasionally when accelerating.
• Shifts rough when transitioning from EV to Hybrid operation on low State of Charge (SoC).

REPAIR SUMMARY:
This bulletin involves reprogramming the TCM with the latest available software.
CLAIMS DATA:
Labor Operation No:

Labor Description

Skill Category

Labor Time

18-19-05-RY

Module, Transmission
Control (TCM) - Reprogram
(0 - Introduction)

2 - Automatic Transmission

0.2 Hrs.

Failure code

CC

Customer Concern

The dealer must use failure code CC with this Technical Service Bulletin.
• If the customer’s concern matches the SYMPTOM identified in the Technical Service Bulletin, failure code CC
is to be used.
• When utilizing this failure code, the 3C’s (customer’s concern, cause and correction) must be provided for
processing Technical Service Bulletin flash/reprogramming conditions.
DIAGNOSIS:
Using a Scan Tool (wiTECH) with the appropriate Diagnostic Procedures available in DealerCONNECT/ Service
Library, verify all related systems are functioning as designed. If Diagnostic Trouble Codes (DTCs) or symptom
conditions, other than the ones listed above are present, record the issues on the repair order and repair as
necessary before proceeding further with this bulletin.
If the customer describes any of the symptoms listed above in the customer symptom section, perform the Repair
Procedure.

21-028-23

-2-

SPECIAL TOOLS/EQUIPMENT:
Description

Ref. No.

Notes

wiTECH or Equivalent

–

–

REPAIR PROCEDURE:
NOTE: Install a battery charger to ensure battery voltage does not drop below 13.2 volts. Do not allow the
charging voltage to climb above 13.5 volts during the flash process.
NOTE: If this flash process is interrupted/aborted, the flash should be restarted.
CAUTION! Additional module flashes are required for this update to be effective. The following modules
are all to be updated along with this update:
• Hybrid Control Processor (HCP), Auxiliary Hybrid Control Processor (AHCP) also known as
the PIM.
• Powertrain Control Module (PCM).
WARNING!
• Before performing the software reprogramming, it is necessary to make the vehicle safe.
• When performing repairs that directly involve or imply possible contact with live high voltage
components/systems, the technician must ensure that the power supply of the high-voltage system is
disconnected throughout the operation.
• Only specifically trained technicians qualified to perform repairs on vehicles with high voltage systems
under current national laws/regulations are authorized to work on the vehicle.
• Before performing any diagnostic repair work on the vehicle, carefully read and comply with the general
instructions for working safely on hybrid/electric vehicles and use suitable general equipment and
Personal Protective Equipment (PPE).

1.
2.
3.

Reprogram the TCM with the latest software. Detailed instructions for flashing control modules
using the wiTECH Diagnostic Application are available by selecting the application’s “HELP” tab.
Clear any DTCs that may have been set in any modules due to reprogramming. The wiTECH
application will automatically present all DTCs after the flash and allow them to be cleared.
Verify the HCP and the PCM are also programmed with the latest available software. Refer to all
applicable published service bulletins for detailed repair procedures and labor times regarding
updating the HCP and the PCM software.

POLICY:
Reimbursable within the provisions of the warranty.
This bulletin is supplied as technical information only and is not an authorization for repair. No part of this publication
may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical,
photocopying, or otherwise, without written permission of FCA US LLC.