2021 Jeep Wrangler PHEV Battery MIL False Illumination TSB
Owners of 2021 Jeep Wrangler PHEV models may encounter a false Malfunction Indicator Lamp (MIL) due to specific battery-related diagnostic trouble codes (DTCs). A software update for the Battery Pack Control Module (BPCM) and other components is available to resolve these issues.
Owners of the 2021 Jeep Wrangler PHEV may experience a false Malfunction Indicator Lamp (MIL) illumination related to their vehicle's plug-in hybrid electric vehicle (PHEV) battery system. This issue, addressed by NHTSA Manufacturer Communication 10248015, indicates that the MIL may turn on without an actual underlying problem with the battery. The communication outlines specific diagnostic trouble codes (DTCs) that trigger this false warning and provides a software update as the solution.
This concern primarily affects the 2021 Jeep Wrangler PHEV battery MIL system, leading to unnecessary worry for vehicle owners. The root cause is often incorrect readings or communication issues within the battery management system, rather than a critical fault with the battery itself.
Symptoms
The primary symptom owners will notice is the illumination of the Malfunction Indicator Lamp (MIL) on the dashboard. This warning light indicates a potential issue with the PHEV battery system. Despite the MIL being active, the vehicle may operate normally, suggesting a false alert rather than a genuine malfunction.
Fault Codes / DTCs
Several specific diagnostic trouble codes (DTCs) have been identified as triggers for the false 2021 Jeep Wrangler PHEV battery MIL illumination. These codes point to various aspects of the battery and control systems:
- P1A21-00: HV Battery Contactor Control Sequence Incorrect
- P0B3E-00: Hybrid/EV Battery Voltage Sense 1 Circuit High
- P0607-00: ECU Internal Performance
- P1E1B-00: Hybrid/EV Battery Side Voltage System Isolation
- P0AA4-00: Hybrid Battery Negative Contactor Circuit Stuck Closed
- P1C00-00: Hybrid/EV Battery Voltage Sense 1 Out Of Range Low
- P1C01-00: Hybrid/EV Battery Voltage Sense 1 Out Of Range High
- P1A9B-00: Hybrid/EV Battery Temperature Sensor 1 Out Of Range High
- P0BBD-00: Hybrid Battery Pack Voltage Variation Exceeded Limit
- P167B-00: Controlled System Shutdown
- U1885-00: Battery Energy Control Module Lost Communication With HCP
- P0EDD-00: Hybrid/EV Battery Pack B Deterioration
- U0111: Lost Communication With Hybrid Battery Pack Sensor Module
- P0CA7-00: Hybrid/EV Battery Discharging Current High
- P1A0C-00: Battery Energy Control Module System Voltage Low
Repair Procedure Summary
The resolution for the false 2021 Jeep Wrangler PHEV battery MIL involves updating the software of several key control modules. This is a flash update designed to correct the diagnostic logic and communication protocols that lead to the erroneous MIL illumination. The primary module targeted is the Battery Pack Control Module (BPCM).
However, for the update to be fully effective, additional modules also require software updates. These include the Powertrain Control Module (PCM), Integrated Dual Charging Module (IDCM), Transmission Control Module (TCM), and the Hybrid Control Processor (HCP), which is also known as the Auxiliary Hybrid Control Processor (AHCP) or Power Inverter Module (PIM).
Owner Action
If you own a 2021 Jeep Wrangler PHEV and are experiencing a false Malfunction Indicator Lamp (MIL) illumination, especially if accompanied by any of the listed DTCs, you should contact your authorized Jeep dealership. The dealership will be able to perform the necessary software updates for the Battery Pack Control Module (BPCM) and other related modules. This software flash is expected to resolve the issue and prevent the MIL from falsely illuminating in the future.
Source: NHTSA ID: 10248015
Frequently Asked Questions
- What does a false Malfunction Indicator Lamp (MIL) mean for my 2021 Jeep Wrangler PHEV?
- A false MIL illumination means that your vehicle's dashboard warning light is on, indicating a problem with the PHEV battery system, but there might not be an actual hardware fault. This is typically due to software logic issues triggering diagnostic trouble codes (DTCs) incorrectly.
- Which DTCs are associated with the false 2021 Jeep Wrangler PHEV battery MIL?
- Several DTCs can cause this issue, including P1A21-00 (HV Battery Contactor Control Sequence Incorrect), P0B3E-00 (Hybrid/EV Battery Voltage Sense 1 Circuit High), P0607-00 (ECU Internal Performance), and many others listed in the manufacturer communication.
- How is the false MIL issue resolved for the 2021 Jeep Wrangler PHEV?
- The issue is resolved by performing a software update (flash) on the Battery Pack Control Module (BPCM) and several other related modules, including the Powertrain Control Module (PCM), Integrated Dual Charging Module (IDCM), Transmission Control Module (TCM), and the Hybrid Control Processor (HCP).
- Should I be concerned if my 2021 Jeep Wrangler PHEV battery MIL comes on?
- While the MIL indicates a potential issue, if it's a false illumination as described in this communication, the underlying problem is software-related rather than a critical battery failure. However, it's always best to have your vehicle inspected by a dealership to confirm the diagnosis and apply the necessary software updates.
What Jeep Wrangler owners report
Counted from the records in our database across 41 model years.
- 18,838
- Owner complaints
- 104
- Recalls
- 2,758
- Service bulletins
- 572
- Crashes reported
- 552
- Fires reported
- 435
- Injuries reported
The 2021 model year
963 complaints, the 5th most of 41 model years on file. Owners reported 21 crashes, 27 fires and 15 injuries for this year, which also has 17 recalls on file.
Electrical System and Exterior Lighting and Back Over Prevention and Power Train, the system this article covers, accounts for 5,833 of 18,838 complaints (31%), including 424 for 2021.
Complaints by model year
| 2006 | 730 | |
|---|---|---|
| 2007 | 1,750 | |
| 2008 | 1,904 | |
| 2010 | 686 | |
| 2012 | 836 | |
| 2014 | 658 | |
| 2018 | 1,827 | |
| 2019 | 747 | |
| 2021 | 963 | |
| 2024 | 970 |
Most-reported systems
- Steering — 3,929
- Electrical System — 3,613
- Power Train — 2,470
- Engine — 2,406
- Fuel System — 2,015
Latest recalls for the 2021 model year
- 26V363000 — Steering (Jun 2026) — Park outside
- 25V741000 — Electrical System (Oct 2025) — Park outside
- 24V720000 — Electrical System (Sep 2024)
Recent owner reports about electrical system and exterior lighting and back over prevention and power train
The contact owns a 2021 Jeep Wrangler 4XE. The contact stated that while driving at 75 MPH, the vehicle lost motive power rapidly and unexpectedly. The contact pulled over to the shoulder before the vehicle stalled.
Read owner complaints →After the Jeep 68C recall fix since January 2026: • Aggressive Battery Throttling & "Bogging": The updated software heavily restricts power output (often capping electric draw around 40–50%) to keep the battery cool.
Complaints are owner reports filed with NHTSA. They are unverified, and counts depend on how many vehicles were sold, so they are not a failure rate.
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