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

TSB: 21-003-24
GROUP: 21 - Transmission and Transfer
Case

Date:

January 10, 2024

VEHICLES
AFFECTED:

2023 (WL) Jeep Grand Cherokee/Grand Cherokee L
This bulletin applies to vehicles equipped with a 2.0L I4 DOHC DI
Turbo PHEV Engine (Sales Code ECX) and a 8-Speed Auto 8P75PH
PHEV Transmission (Sales Code DFY).

REVISION: –

MARKET APPLICABILITY:
NA

MEA

SA

IAP

EE

CH

CUSTOMER
SYMPTOM:

Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation
the technician may find the following Diagnostic Trouble Code (DTC) has been set in the Hybrid Control
Processor (HCP) module:
● P16F0-00 - SPI Comm Hardware Fault.
Customers may also comment on one or more of the following:
● 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 SoC.
● Shifts rough when engines starts.
● On part throttle accelerations with little to no battery available the transition from battery power to engine on
is harsh and abrupt.
● The engine oil life on dashboard drops down too fast when the engine oil dilution reaches high level without
the ability to recover.

CAUSE:

Module Software Updates

REPAIR SUMMARY:
This bulletin involves reprogramming the TCM, Powertrain Control Module (PCM) and the Auxiliary Hybrid
Control Processor (AHCP) also known as Power Inverter Module (PIM), with the latest available software.
CLAIMS DATA:
Labor Operation No:
18-19-17-9X

Failure Code

Labor Description
Reprogram Powertrain
Control (PCM),
Transmission Control
(TCM), and
Hybrid Control Processor/
Auxiliary Hybrid Control
Processor (HCP/AHCP)
(0 - Introduction)
CC

Skill Category
1 - Engine Repair And
Performance

Labor Time
0.6 Hrs.

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
CCis to be used.

M21 FSAR-TSB-3599

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● 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 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.
SPECIAL TOOLS/EQUIPMENT:
Description
wiTECH or Equivalent

Ref. No.
–

Notes
–

REPAIR PROCEDURE:
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).
NOTE: Install a battery charger to ensure sufficient battery voltage is provided during the flash
process.
NOTE: If this flash process is interrupted/aborted, the flash should be restarted.
1. Disable HV battery contactors with wiTECH - Go to the Misc Functions tab select "Disable HV Battery
Contactors" then follow the wiTECH prompts.
2. Using wiTECH confirm that the contactors are open and waiting five minutes. If the contactors do not
open place ignition in the ON position, then OFF. Once successful, a note will appear on the wiTECH
screen indicating the contactors are open.
3. Reprogram the PCM with the latest available software. Detailed instructions for flashing control modules
using the wiTECH Diagnostic Application are available by selecting the application’s “HELP” tab.
4. Reprogram the HCP and AHCP with the latest software. Detailed instructions for flashing control modules
using the wiTECH Diagnostic Application are available by selecting the application’s “HELP” tab.
5. 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.
6. 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.
7. Enable HV battery contactors with wiTECH - Go to the Misc Functions tab select "Enable HV Battery
Contactors For Service" then follow the wiTECH prompts.

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M21 FSAR-TSB-3599

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.