2021 Jeep Wrangler MIL Illumination TSB 08-314-25
This Technical Service Bulletin (TSB) 08-314-25, revision 08-020-22, addresses Malfunction Indicator Lamp (MIL) illumination and specific Diagnostic Trouble Codes (DTCs) in 2021 Jeep Wrangler vehicles equipped with the Premium Alpine Speaker System. The issue is resolved by updating the Amplifier…
Owners of certain 2021 Jeep Wrangler vehicles may notice a "Malfunction Indicator Lamp (MIL) illumination" on their dashboard, often accompanied by specific Diagnostic Trouble Codes (DTCs). This issue, detailed in Technical Service Bulletin (TSB) 08-314-25, revision 08-020-22, points to a software problem within the vehicle's amplifier module. This bulletin supersedes the previous Technical Service Bulletin (TSB) 08-020-22, issued on January 27, 2022.
This bulletin applies to 2021 Jeep Wrangler models equipped with the Premium Alpine Speaker System (Sales Code RC3) that were built between June 21, 2021 (MDH 0621XX) and September 06, 2021 (MDH 0906XX). The problem stems from faulty amplifier software, which causes the vehicle to incorrectly set certain DTCs without actually affecting the Active Noise Cancellation (ANC) performance. This TSB is applicable to vehicles in North and South America, Enlarged Europe, Middle East & Africa, India & Asia Pacific, and China markets.
Symptoms
If your 2021 Jeep Wrangler is affected, you will experience a "Malfunction Indicator Lamp (MIL) illumination" on your instrument cluster. This warning light indicates that the vehicle's computer has detected a fault.
Fault Codes / DTCs
When the "Malfunction Indicator Lamp (MIL) illumination" occurs, a scan tool will likely reveal one or more of the following Diagnostic Trouble Codes (DTCs):
| Code | Description |
|---|---|
| B143B-12 | ANC Microphone 1-Circuit Short To Battery |
| B143C-12 | ANC Microphone 2-Circuit Short To Battery |
| B143E-12 | ANC Microphone 3-Circuit Short To Battery |
| B143F-12 | ANC Microphone 4-Circuit Short To Battery |
It is important to note that these DTCs are often wrongly set and do not affect the Active Noise Cancellation (ANC) performance of your Jeep Wrangler MIL illumination.
Diagnosis
Before proceeding with the repair, a technician will use a wiTECH scan tool to verify all related systems are functioning as designed. If other DTCs or symptom conditions are present, they must be addressed first. If the customer reports the symptoms described in this bulletin, the repair procedure outlined below should be followed.
Repair Procedure Summary
The primary repair involves updating the Amplifier (AMP) module with the latest available software. This process requires specific steps to ensure proper execution and prevent further issues.
- Check for DTCs: The technician will first check if DTC B143B-12 is stored. If it is, they will proceed to the next step. If not, they will follow standard diagnostic procedures.
- Reprogram AMP Module: The Amplifier (AMP) module will be reprogrammed with the most current software using the wiTECH Diagnostic Application. If any issues arise during this flashing process, the technician is instructed to submit a ticket to the Helpdesk.
- Perform EPS Reset: After the AMP software update, an Electric Power Steering (EPS) reset must be performed using the wiTECH tool. This involves navigating to the “Guided Diagnostics” menu, selecting
Frequently Asked Questions
- What does TSB 08-314-25 address for my 2021 Jeep Wrangler?
- TSB 08-314-25, revision 08-020-22, addresses instances where the Malfunction Indicator Lamp (MIL) illuminates and specific Diagnostic Trouble Codes (DTCs) related to the ANC Microphone circuits (B143B-12, B143C-12, B143E-12, B143F-12) are set in 2021 Jeep Wrangler vehicles equipped with the Premium Alpine Speaker System. The root cause is identified as faulty amplifier software.
- Will my Active Noise Cancellation (ANC) performance be affected if I see these DTCs?
- No, according to TSB 08-314-25, the Diagnostic Trouble Codes (DTCs) like B143B-12, B143C-12, B143E-12, and B143F-12 are wrongly set and do not actually affect the Active Noise Cancellation (ANC) performance in your 2021 Jeep Wrangler.
- What is the repair for the Jeep Wrangler MIL illumination issue?
- The repair involves updating the Amplifier (AMP) module with the latest available software using a wiTECH diagnostic tool. Additionally, an Electric Power Steering (EPS) module reset is required after the software update to prevent other error messages, such as "service the Ambient Light Module".
- Are there any precautions during the software update process?
- Yes, a battery charger must be installed to ensure the battery voltage remains between 13.2 and 13.5 volts during the flash process. If the flash process is interrupted for any reason, it must be restarted.
- Is this repair covered under warranty?
- Yes, this repair is reimbursable within the provisions of the vehicle's warranty. The labor operation for this service is 18-60-07-9D, with an estimated time of 0.3 hours, and the failure code to be used by the dealer is CC.
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, the system this article covers, accounts for 3,613 of 18,838 complaints (19%), including 313 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
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.
Related Articles
2021 Jeep Wrangler Health Check: Recalls and Bulletins
The 2021 Jeep Wrangler has faced several significant issues, including recalls for potential engine stalls, high voltage battery fires in 4Xe models, and instrument panel failures. Owners should be aware of these safety concerns and numerous service bulletins addressing various electrical, engine…
2021 Jeep Wrangler DTCM Update for 4WD System Issues
Learn about TSB 08-366-26 for the 2021 Jeep Wrangler, which resolves Malfunction Indicator Lamp (MIL) illumination and 4WD system issues related to DTC C147B-92 by updating the Drivetrain Control Module (DTCM) software.
2017-2026 Chrysler, Dodge, Jeep Passive Entry Door Handle TSB
A technical service bulletin (TSB S2623000040) addresses inoperative passive entry door handles on various 2017-2026 Chrysler, Dodge, and Jeep models, instructing technicians to perform a specific online procedure before considering handle replacement.
2021-2026 Stellantis KeyFOB Low Battery DTCs B1A10-00
Stellantis TSB S2608000010 addresses diagnostic trouble codes B1A10-00 through B1A17-00 related to KeyFOB low battery conditions in 2021-2026 Chrysler, Dodge, Jeep, and RAM vehicles. Symptoms include inoperable remote keyless entry or passive start. Learn the recommended fix.
2021-2026 Jeep Wrangler/Gladiator Handle Release Parts
A Quality Inspection Request has been issued for specific 'HANDLE - INSIDE RELEASE' parts (68282334AD, 68282335AD, 68282336AD, 68282337AD, 68323950AD, 68323951AD) affecting 2021-2026 Jeep Wrangler and Gladiator vehicles. Parts built before August 7, 2025, are suspect and require return.
Leave a comment
Comments are moderated and may take a moment to appear. Only your first name and the initial of your last name are shown publicly.
Comments
Be the first to comment.