We monitored five owner forums and three Facebook groups in the 72 hours post-patch release. The early verdict is remarkably positive.
The dongle fault usually happens when the car's engine computer (ECU) and its security system stop talking to each other. When this happens, the car shows an error code like .
While older capture-replay flaws (like CVE-2022-38766 on the 2021 Renault ZOE) allowed attackers to sniff and replay signals to unlock doors, newer patches focus on rolling code encryption to make these DIY hacks nearly impossible on modern push-to-start models. The Impact of Recent Cyber Attacks After JLR, Hackers Have Turned On Renault
The "fault" in question was not a typical mechanical failure, but rather a cybersecurity vulnerability found in aftermarket or older third-party OBD-II (On-Board Diagnostics) dongles used with Renault vehicles. These dongles are often employed for performance tracking, diagnostic checks, or connecting to third-party telematics apps. renault dongle fault patched
The affected device is a hardware interface (dongle) used for:
The vulnerability targeted the cryptographic handshake between the Renault smart key fob (often called the hands-free card or dongle) and the vehicle’s Body Control Module (BCM). The Security Flaw
: Developing and deploying patches shows a commitment to product quality and customer satisfaction. It also highlights the importance of ongoing support and maintenance for connected and software-enabled vehicles. We monitored five owner forums and three Facebook
: The car thinks someone is trying to steal it because a data file got corrupted during a normal start cycle. How the New Patch Works
The problem? A critical firmware flaw in the dongle’s power management sleeping protocol.
The good news is that this immobiliser dongle fault is now a well-understood problem with multiple proven solutions—a "patch" in the truest sense. A few years ago, this issue would have almost certainly meant an expensive and frustrating trip to a Renault dealership for a full UCH replacement. Today, thanks to advanced aftermarket diagnostic tools and a better understanding of the fault, it is a problem that can be resolved quickly and affordably. When this happens, the car shows an error code like
Thieves utilized affordable, off-the-shelf hardware—such as Software Defined Radios (SDRs) and specialized OBD-II dongles—to execute two primary types of attacks:
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In affected Renault models, the proprietary algorithm managing the rolling codes and challenge-response handshakes contained a logic flaw. Security researchers discovered that the cryptographic keys used to validate the transponder were not sufficiently randomized. Instead, they relied on predictable variables derived from public vehicle data, such as the Vehicle Identification Number (VIN) or standard OBD-II diagnostic responses. The Attack Vector
The patch introduces a secure gateway to the vehicle's BCM. If an unauthorized device attempts to force key-programming mode through the OBD-II port, the system triggers a localized lockdown. Only certified Renault diagnostic tools with an active token from Renault's secure corporate servers can now program new keys. How to Get Your Vehicle Patched