U0111 on 2021-2022 Jeep Wrangler 4xe: Lost Communication with Battery Module Fixes

What's Unique About the 2019-2022 Jeep WRANGLER

This code is specific to the Jeep Wrangler 4xe plug-in hybrid (PHEV), introduced in the 2021 model year. It does not apply to non-hybrid Wranglers. The 4xe platform has been subject to numerous software updates and recalls related to its complex hybrid powertrain. A key issue documented in Technical Service Bulletin S2108000056RevD is the BPCM's tendency for its circuit board to fail to 'wake up' and communicate in single-digit or below-freezing ambient temperatures. This is separate from, but related to, other cold-weather behaviors like Fuel and Oil Refresh Mode (FORM), where the vehicle runs the gas engine to protect it, which has been a point of confusion and frustration for owners in cold climates.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp) is on
• "Service Charging System" message on the dash
• Vehicle will not start or 'ready' light does not come on
• Complete and sudden loss of motive power while driving
• Inability to charge the high-voltage battery
• Vehicle enters a 'safe mode' or limp mode with reduced power
• 12V battery may become depleted or show low voltage on the gauge
• Vehicle may not shift out of Park

Most Likely Causes

1. Battery Pack Control Module (BPCM) Internal Failure 🔴 High Probability A known issue, documented in TSB S2108000056RevD, shows that some BPCM circuit boards have a variation making them susceptible to failure in single-digit or below-freezing ambient temperatures, causing them to not 'wake up' and communicate.
   How to confirm: A dealer technician will follow diagnostic procedures for U0111. If the fault occurred in very cold weather, TSB S2108000056RevD points directly to BPCM failure as the likely cause. The TSB states that once the BPCM enters this state, it will remain offline until power is removed.
   Typical fix: Replacement of the Battery Pack Control Module (BPCM). On these vehicles, the BPCM is located inside the high-voltage battery assembly, so this often means replacing the entire HV battery pack. The TSB notes a revised BPCM was expected in late 2022 to rectify the issue.
   Est. part cost: $4000-$6000
2. Software Glitch in Hybrid Control Modules 🟡 Medium Probability The Wrangler 4xe platform has had multiple recalls and software updates. Recall 22V-865 (Campaign ZB7) was issued for 62,909 vehicles for a defect where communication loss could cause engine shutdown. Additionally, TSB 08-141-21 (superseded by RSU 23-037) addresses false MILs for U0111 that can be fixed with a software flash.
   How to confirm: A dealer will check for open recalls or available software updates for the Hybrid Control Processor (HCP), Auxiliary Hybrid Control Processor (AHCP), Transmission Control Module (TCM), and BPCM.
   Typical fix: Updating the software of the relevant control modules. Recall ZB7 specifies a critical update sequence: first the BPCM must be up to date, then the AHCP, then the HCP, and finally the TCM. This must be done at a dealership with a wiTECH scan tool.
   Est. part cost: $0
3. Wiring or Connector Issues ⚪ Low Probability While less common, any vehicle can suffer from damaged wiring or corroded/loose connectors. On the related Chrysler Pacifica Hybrid platform, a similar BPCM communication code (U11C5) was traced back to a loose 12V power connection at a distribution post, which caused the entire 12V system to intermittently go down.
   How to confirm: Visual inspection of the wiring harnesses connected to the high-voltage battery and associated control modules. A technician should also check for stable voltage at main power distribution points. This should be done by a professional due to the high-voltage risk.
   Typical fix: Repairing the damaged wire or cleaning/tightening the affected connector.
   Est. part cost: $10-$100

Rare But Worth Checking

• Failing 12V Auxiliary Battery:

Diagnosis Steps

1. Verify the code with a professional-grade OBD-II scanner capable of reading manufacturer-specific 'U' codes.
2. Check the health of the 12V battery with a load tester. A weak 12V battery can cause numerous communication faults and should be ruled out first.
3. Check for any open recalls, particularly NHTSA recall 22V-865 (ZB7), or Technical Service Bulletins (TSBs) like S2108000056RevD and RSU 23-037.
4. If the failure occurred in very cold temperatures (single digits F or below), suspect a faulty BPCM as per TSB S2108000056RevD.
5. Have a dealer check for and apply any available software updates using a wiTECH scan tool. This is a critical step, as multiple issues are resolved by flashing modules. The flash order for recall ZB7 is BPCM -> AHCP -> HCP -> TCM.
6. If software updates do not resolve the issue, a technician should inspect the CAN bus network wiring and power/ground connections to the BPCM for faults, corrosion, or looseness.
7. If the diagnostic flowchart leads to BPCM replacement, the high-voltage battery pack will likely need to be replaced as an assembly.

Parts You'll Likely Need

• High-Voltage Battery Pack Assembly (OEM #VIN-dependent, not a single universal part number.) — The most common hardware cause for this code is an internal failure of the Battery Pack Control Module (BPCM). The BPCM is integrated into the HV battery pack and is not serviced separately, requiring replacement of the entire assembly.
  Trusted brands: Mopar
  OEM price range: $4000-$6000
  Aftermarket price range: N/A

Related Codes That Often Appear With This One

• U1885-00 — This code, "Battery Energy Control Module Lost Communication With HCP," is often logged alongside U0111 as they both relate to the same communication failure between the BPCM and the Hybrid Control Processor. [TSB #0804823, 9]
• P0EDD-00 — "Hybrid/EV Battery Pack B Deterioration." This code may be set when the system loses communication with the BPCM, as it can no longer monitor the battery's state of health. [TSB #08-141-21, TSB #0805422REVB, 9]
• P0CA7-00 — "Hybrid/EV Battery Discharging Current High." This can be triggered as a result of the control module malfunction indicated by U0111. [TSB #0805422REVB, 9]
• Multiple Low Voltage DTCs — TSB S2108000056RevD notes that when the BPCM goes offline, it can cause the 12v battery to become depleted, leading to a variety of low voltage codes across different modules.

Technical Service Bulletins (TSBs) & Recalls

• S2108000056RevD: Discusses BPCM circuit board failure in very low ambient temperatures, causing U0111.
• 08-141-21 / RSU 23-037: Mentions a software update for the BPCM to fix a false MIL illumination for U0111 and other codes.
• 0804823 & 0805422REVB: List U0111 as "Lost Communication With Hybrid Battery Pack Sensor Module" in conjunction with other hybrid battery codes.
• NHTSA Recall 22V-865 (ZB7): Details a software fix for communication loss that can lead to engine shutdown.

Platform-Specific Known Issues

• TSB S2108000056RevD specifically calls out that some BPCM circuit boards may fail to communicate in single-digit or colder ambient temperatures, directly causing code U0111.
• NHTSA recall 22V-865 affects 62,909 Wrangler 4xe models (2021-2023) for software issues that can cause a loss of communication between hybrid modules, resulting in an unexpected engine shutdown and loss of motive power.
• TSB 08-141-21 and its successor RSU 23-037 note that a false Malfunction Indicator Lamp (MIL) for code U0111 can be caused by a software issue, which can be resolved by updating the BPCM and other related control module software.

Scan Tool Commands That Help

• wiTECH: Reprogram BPCM — Used to apply software updates as specified in multiple TSBs (e.g., RSU 23-037) to fix false MIL illumination for U0111 and other related codes.
• wiTECH: Disable HV Battery Contactors — This is a mandatory safety step before performing software reprogramming or any service on the HV system. It's found under the 'Misc Functions' tab.
• wiTECH: Enable HV Battery Contactors For Service — Used after service or reprogramming is complete to re-energize the high-voltage system.
• wiTECH: High-Voltage Power Down / Power Up Procedure — A standard procedure required before and after BPCM reprogramming or replacement to ensure technician safety and proper system reset.
• JScan: Live Data > HV battery state of health percentage — While not a direct diagnostic for a communication code, this allows owners with an OBD2 reader and the JScan app to monitor the battery's health, which can be useful data if communication is intermittent.

Wiring & Ground Locations

• High-Voltage Battery Pack — Located inside the passenger compartment, underneath the rear seats.. This is the physical location of the BPCM, which is integrated into the battery assembly. Accessing the module or its connectors requires removing the rear seats.
• Main Fuse Panel (Power Distribution Center) — Located in the engine compartment on the passenger side, just behind the 12V battery.. This panel contains fuses and relays that supply power to various modules, including potentially the BPCM's power supply. A fault here could interrupt power and cause a communication loss.
• Underhood Ground Points — There are multiple ground studs under the hood. A key set of three is located near the 12V battery on the passenger side, with another farther forward towards the air box.. A poor ground connection for any of the hybrid control modules can cause intermittent communication faults like U0111. These points should be inspected for corrosion and tightness.

Real Owner Repair Stories

• jlwranglerforums.com user (Jeep Wrangler 4xe (year not specified)) — Vehicle sat for 3 weeks. 12V battery was at 4 volts. After charging and starting, the battery light was on, the gauge showed low voltage (11.7V), and the check engine light was on with code U0111.
  ❌ Tried (didn't work) Initially, just charging and starting the vehicle did not clear the code or symptoms.
  ✅ What actually fixed it After charging the 12V battery, the owner disconnected both 12V battery cables for about 30 minutes. Upon reconnecting, all warning lights and codes were gone and the vehicle returned to normal operation. This indicates a module reset cleared the fault after the root cause (discharged 12V battery) was addressed.

OEM Part Supersession History

• Various BPCM circuit boards → Revised BPCM — To rectify a low ambient temperature failure where the BPCM would not wake up and communicate.

Model Year Variations Within This Range

• 2021-2022: TSB S2108000056RevD, released in August 2022, notes that a revised BPCM was being developed and expected in late 2022 to fix the cold-weather failure issue. This implies that 2021 and early 2022 models may have the susceptible BPCM, while later models may have the revised part from the factory.