Technical Service Bulletin (TSB)
Flash: Battery Pack Control Module (BPCM) Updates
REFERENCE:

TSB: 08-034-26
GROUP: 08 - Electrical

Date:

January 31, 2026

VEHICLES
AFFECTED:

2024 (JL) Jeep Wrangler
This bulletin applies to vehicles equipped with the 2.0L I4 DOHC DI
Turbo PHEV Engine (Sales Code ECX).

REVISION: 08-034-25

MARKET APPLICABILITY:
NA

IAP

EE

MEA

SA

CH

This bulletin applies to
the North America, Enlarged
Europe, Middle East & Africa,
China and India & Asia Pacific
markets.
CUSTOMER
SYMPTOM:

Customers must experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation
the technician must find one or more of the following Diagnostic Trouble Codes (DTCs) have been set:
● **P0B28-00 Hybrid/EV Battery "B" Voltage Unstable.**
● P0DAB-00 - Hybrid/EV Cell Balancing Performance.
● P0607-00 - ECU Internal Performance.
● P0AA1-00 - Hybrid/EV Battery Positive Contactor “A” Stuck Closed.
● P0AA4-00 - Hybrid Battery Negative Contactor Circuit Stuck Closed.
● P0C78-00 - Hybrid/EV Battery System Precharge Time Too Long.
● P0CA6-00 - Hybrid/EV Battery Charging Current High.
● P0B24-00 - Hybrid/EV Battery "A" Voltage Unstable.
● P1C5E-00 - Hybrid/EV Battery State Of Health Failied.
● P0BBE-00 - Hybrid/EV Battery Pack Voltage Variation.
**Customers may also comment on the following:
● Vehicle does not start.
NOTE: The no start condition is accompanied with one or more of the following DTCs: P0DAB-00,
P0607-00, P0AA1-00, P0AA4-00, P0C78-00, P0CA6-00, P0B24-00, P1C5E-00 and/or P0BBE-00.
P0B28-00 will result in a MIL for 49 days. After 49 days of the MIL, the vehicle will no longer be
allowed to start.**

CAUSE:

BPCM software

This bulletin supersedes Technical Service Bulletin (TSB) 08-034-25, date of issue February 08, 2025,
which should be removed from your files. All revisions are highlighted with **asterisks** and include
converting the bulletin from an RSU to a TSB, new Market note, an additional DTC, new Customer
Symptom and Note, new Repair Summary, new LOP, new Diagnosis statement and new Repair
Procedure. Other changes not asterisked include the removal of a build date.
This Technical Service Bulletin (TSB) has also been released as a Rapid Service Update (RSU) 23-322,
date of issue November 21, 2023. All applicable RSU VINs have been loaded. To verify this RSU service
action is applicable to the vehicle, use VIP or perform a VIN search in DealerCONNECT/Service Library.
All repairs are reimbursable within the provisions of warranty.

B08 FSAR-TSB-6895

-2-

REPAIR SUMMARY:
**This bulletin involves reprogramming the BPCM with the latest available software.**
CLAIMS DATA:

Labor Operation No:
**18-19-87-AU

Failure Code

Labor Description
Battery Pack Control
Module (BPCM),
Reprogram
(0 - Introduction)
CC

Skill Category
6 - Electrical and Body
Systems

Labor Time
0.3 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
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 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 the symptom/condition above, 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).
● The vehicle must not be connected to a high voltage charger when performing software updates.

-3-

B08 FSAR-TSB-6895

NOTE: Install a battery charger to maintain a 12 volt system voltage.
NOTE: If this flash process is interrupted/aborted, the flash should be restarted.
1. Has the 95B recall instructions been completed on this vehicle?
● YES>>> Proceed to Step 2.
● NO>>> Follow the 95B Recall Instructions and utilize the LOPs contained within the Recall.
2. Disable HV Battery Contactors using wiTECH - Go to the Misc Functions tab --> Select Disable HV Battery
Contactors --> then follow the wiTECH prompts.
3. Use wiTECH to confirm that the contactors are open and waiting five minutes. If the contactors do not
open turn the ignition on then off. Once successful a note will appear on the wiTECH screen indicating the
contactors are open.
4. Reprogram the BPCM with the latest software. If issues arise when flashing a module using the wiTECH
Diagnostic Application, please submit a ticket to the Helpdesk. The helpdesk can be found within the Help
menu.
5. Enable HV Battery Contactors using wiTECH - Go to the Misc Functions tab --> Select Enable HV Battery
Contactors For Service--> then follow the wiTECH prompts.
6. Perform a Drive Cycle Routine using wiTECH - Go to BPCM --> Go to the System Tests tab --> Select
95B / 96B Drive Cycle --> then follow the wiTECH prompts.
7. Clear all DTCs that may have been set in any module due to reprogramming. The wiTECH application will
automatically present all DTCs after the flash and allow them to be cleared.**
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.