2023-2025 Jeep/RAM Loss of Communication TSB 9100389
This manufacturer communication, identified as TSB 9100389, addresses instances where owners report a 'MIL light on' and technicians find a 'loss of communication' diagnostic trouble code (DTC) in 2023-2025 Jeep Wrangler, Gladiator, and various RAM truck models.
Also applies to
- Jeep Gladiator
- 2023–2025
- Jeep Wrangler
- 2024–2025
- Ram 1500
- 2024
- Ram 2500
- 2023–2024
- Ram 4500
- 2023–2024
- Ram 5500
- 2023–2024
Owners of 2023-2025 Jeep Wrangler, Jeep Gladiator, and various RAM truck models may encounter a 'MIL light on' (Malfunction Indicator Lamp) accompanied by diagnostic trouble codes (DTCs) indicating a 'loss of communication' with one or more vehicle modules. This issue is addressed by Manufacturer Communication 9100389, an internal document designed to guide dealership technicians in properly diagnosing the root cause.
This communication, part of the GPOP - Issue Review System, highlights a trend where technicians were frequently replacing the CAN Star Block Connector without confirming its defect, leading to 'no trouble found' on returned parts. The purpose of TSB 9100389 is to provide a clear, multimeter-based diagnostic procedure to accurately determine if the CAN Star Block Connector is indeed faulty, thereby ensuring correct repairs and avoiding unnecessary part replacements for the Jeep RAM loss of communication issue.
Symptoms
Owners typically notice the 'MIL light on' illuminating on their dashboard. This warning light indicates that the vehicle's onboard diagnostic system has detected a malfunction. When a technician scans the vehicle's computer, they will find one or more diagnostic trouble codes (DTCs) specifically related to a 'loss of communication' with various electronic control modules within the vehicle. These communication errors can affect the performance and functionality of multiple systems, potentially leading to unpredictable vehicle behavior or reduced performance. Addressing the Jeep RAM loss of communication promptly is crucial for vehicle reliability.
Fault Codes / DTCs
Manufacturer Communication 9100389 indicates that technicians will find a
Frequently Asked Questions
- What does 'MIL light on' mean in my Jeep or RAM vehicle?
- The 'MIL light on' (Malfunction Indicator Lamp), often referred to as the check engine light, indicates that your vehicle's onboard diagnostic system has detected a fault. In the context of TSB 9100389, it specifically points to a potential 'loss of communication' within the vehicle's network, possibly due to a faulty CAN Star Block Connector.
- What is a CAN Star Block Connector and why is it important?
- The CAN (Controller Area Network) Star Block Connector is a crucial component in your vehicle's electrical system. It acts as a central hub, allowing various electronic control modules (ECMs) to communicate with each other. A malfunction in this connector, as described in TSB 9100389, can lead to a 'loss of communication' between modules, triggering warning lights and affecting vehicle functions.
- How is a 'loss of communication' DTC diagnosed according to TSB 9100389?
- Manufacturer Communication 9100389 outlines a five-step diagnostic procedure. This involves visually inspecting the CAN Star Block Connector for physical damage, measuring resistance between specific pins (expecting 120.4 to 139.8 Ohms), and checking for continuity between pins in different connector cavities using a multimeter. These steps help technicians accurately identify if the connector is indeed defective.
- Will my dealership be aware of Manufacturer Communication 9100389?
- Yes, Manufacturer Communication 9100389 is an internal document distributed to dealerships to assist their technicians with specific diagnostic and repair procedures. If you are experiencing a 'MIL light on' or 'loss of communication' DTC, you should inform your service advisor about these symptoms, and they should be able to reference this TSB for proper diagnosis and repair.
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 2023 model year
378 complaints, the 20th most of 41 model years on file. Owners reported 11 crashes, 7 fires and 8 injuries for this year, which also has 16 recalls on file.
Electrical System, the system this article covers, accounts for 3,613 of 18,838 complaints (19%), including 202 for 2023.
Complaints by model year
| 2006 | 730 | |
|---|---|---|
| 2007 | 1,750 | |
| 2008 | 1,904 | |
| 2010 | 686 | |
| 2012 | 836 | |
| 2018 | 1,827 | |
| 2019 | 747 | |
| 2021 | 963 | |
| 2023 | 378 | |
| 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 2023 model year
- 26V363000 — Steering (Jun 2026) — Park outside
- 25V741000 — Electrical System (Oct 2025) — Park outside
- 25V710000 — Electrical System (Oct 2025)
Recent owner reports about electrical system
Upon starting vehicle, the instrumentation cluster has lost all power. There was a recall for this issue prior and jeep is stating that my vehicle was not part of the recall.
Read owner complaints →Aug 6 2026 turtle limp mode came on. Lost power. Sept 5,6 turtle mode came on. Slowed to a crawl with several cars behind me. Oct 3 turtle limp mode came on. Lost power thru intersection. Thankfully no oncoming traffic. Oct 4 turtle limp mode came on.
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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