The realm of automotive security and performance enhancement is vast and often riddled with more hype than substance. From intricate CAN bus manipulations to promises of boosted horsepower and fuel efficiency, the possibilities – and potential pitfalls – are numerous. Our team at techcarusa.com, deeply immersed in exploring the intricacies of vehicle technology, has spent considerable time dissecting the Controller Area Network (CAN bus) and various devices interacting with it.
Recently, a friend brought to our attention a compact On-Board Diagnostic (OBD) dongle marketed as the “Nitro OBD2”. This device claims to be a “Chip Tuning Box” that simply plugs into your car’s OBD2 port to magically unlock increased performance. While online testimonials are a mixed bag, ranging from outright dismissal to anecdotal success stories, we decided to take a hands-on approach. Driven by curiosity and a healthy dose of skepticism, we purchased a Nitro OBD2 from Amazon and embarked on a reverse engineering journey to uncover its true nature. Unable to leave a comprehensive review on the retail platform, we’re bringing our findings to you in this blog post.
PCB Teardown: Peeking Inside the Nitro OBD2
Before even considering connecting this device to a vehicle, our first step was to examine its internal components. Opening the Nitro OBD2 dongle revealed a standard OBD2 connector pinout, as expected for any device interfacing with a car’s diagnostic port. The initial visual inspection confirmed connections to pins associated with the CAN bus, J1850 bus, and ISO 9141-2 protocols – critical for automotive communication.
Here’s a look at the pinout:
OBD2 connector pinout diagram for Nitro OBD2 dongle, highlighting pin assignments.
Upon closer examination of the printed circuit board (PCB), it became apparent that only the pins relevant to CAN communication were actually connected to the central chip. The other connected pins were solely linked to the onboard LEDs, suggesting a very limited functionality beyond basic power and indicator lights.
The internal layout of the Nitro OBD2 is deceptively simple:
Internal circuit board of the Nitro OBD2 dongle, showing basic components and connections.
Based on this initial PCB analysis, we could deduce a rudimentary schematic:
- A basic power supply circuit.
- A push button, likely for reset or perhaps no function at all.
- A single, unidentifiable chip.
- Three LEDs for visual feedback.
Notably absent was a dedicated CAN transceiver chip. This raised immediate red flags. Either the CAN transceiver was integrated directly into the main chip, or, more likely, the device lacked genuine CAN communication capabilities altogether. For a device claiming to reprogram engine control units (ECUs) and modify vehicle performance, the software and hardware would need to be sophisticated. The fact that everything seemed to hinge on a single, small SOP-8 package chip fueled our skepticism. Could genuine ECU reprogramming technology really be crammed into such a minimal setup?
CAN Bus Monitoring: Does Nitro OBD2 Actually Communicate?
To ascertain if the Nitro OBD2 was actively interacting with the car’s systems, we needed to monitor its CAN bus activity. Our approach was straightforward: record CAN bus traffic before and after plugging in the Nitro OBD2 and analyze any differences.
For our testing, we utilized a 2012 Suzuki Swift diesel, a vehicle familiar to us for OBD2 communication via an ELM327 adapter and Android’s Torque app. This car provided a known baseline for typical CAN bus traffic. We employed a Raspberry Pi equipped with a PiCAN2 shield and Stan’s python-socketcan-monitor (a modified version of https://github.com/P1kachu/python-socketcan-monitor) to log CAN messages directly from the OBD2 port.
Our CAN bus monitoring setup is illustrated below:
To ensure the integrity of our setup, we also used a PicoScope to visually inspect the CAN High (CAN_H) and CAN Low (CAN_L) signals, confirming expected CAN bus activity.
PicoScope capture of CAN High and CAN Low signals from the Suzuki Swift’s OBD2 port, verifying active CAN communication.
With a working CAN bus monitoring station, we proceeded to capture CAN traffic with the Nitro OBD2 connected. Since the car only has one OBD2 port, we opted to integrate our monitoring tool directly into the Nitro OBD2 device.
We carefully opened the Nitro OBD2 again and soldered wires to the Ground, CAN_High, and CAN_Low pins on its PCB. These wires were then connected to our Raspberry PiCAN2 interface, allowing us to intercept and record CAN bus traffic while the Nitro OBD2 was plugged into the car.
This modified setup, with wires connected for CAN sniffing, is shown here:
Nitro OBD2 dongle opened with wires soldered to CAN bus pins for external monitoring and traffic analysis.
CAN Bus Traffic Analysis: The Silent Dongle
Analyzing the captured CAN bus logs revealed a stark reality. First, the baseline CAN bus traffic without the Nitro OBD2:
Then, the CAN bus traffic with the Nitro OBD2 plugged in:
Comparison of CAN bus traffic logs: No discernible difference observed with Nitro OBD2 connected, indicating no active communication from the device.
A side-by-side comparison of these traffic logs immediately revealed a critical finding: no new messages appeared when the Nitro OBD2 was connected. The CAN bus traffic remained virtually identical. This strongly suggested that the Nitro OBD2 was not transmitting any data onto the CAN bus.
Our CAN bus analysis pointed to a device that passively observes CAN_H and CAN_L signals, likely to detect general CAN activity and trigger its LEDs, but does not actively communicate or transmit any performance-altering commands.
Chip Decap: Unveiling the Microcontroller
Having established that the Nitro OBD2 was not communicating on the CAN bus, we delved deeper into the mystery of the single chip on its PCB. Lacking any identifying markings, we couldn’t simply consult a datasheet. Driven by scientific curiosity, we decided to decap the chip to examine its internal structure.
After subjecting the chip to sulfuric acid at 200°C, we obtained a die image revealing the chip’s internal architecture:
Within the chip’s silicon, we could identify standard microcontroller components – RAM, Flash memory, and a CPU core. However, there was no evidence of specialized embedded devices like a dedicated CAN transceiver. This further solidified our suspicion: the Nitro OBD2 chip was likely a general-purpose microcontroller, not a custom automotive performance chip.
To provide a visual comparison, we decapped a genuine CAN transceiver, the TJA1050 – a common and widely used chip – and placed it next to the Nitro OBD2’s chip:
Die comparison: TJA1050 CAN transceiver (left) and Nitro OBD2 microcontroller (right). The distinct architectures highlight the absence of a transceiver in the Nitro OBD2 chip.
The stark contrast in design is unmistakable. The TJA1050 CAN transceiver exhibits a clearly different layout compared to the Nitro OBD2 chip. Furthermore, the size and complexity of a CAN transceiver would necessitate a larger die area than what we observed in the Nitro OBD2 chip. This microscopic analysis definitively confirmed our hypothesis: the Nitro OBD2 chip does not incorporate a CAN transceiver and is incapable of CAN bus communication.
Playing Devil’s Advocate: Addressing Potential Counterarguments
Despite our comprehensive analysis, some might still harbor doubts or raise counterarguments to defend the Nitro OBD2’s claims. Let’s address some of these potential points:
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“It needs 200km to become effective”: This is a common claim in dubious performance products – a delay tactic to mask the placebo effect. Our CAN bus monitoring started immediately upon plugging in the device and continued throughout a test drive, capturing any potential initial communication. The absence of any transmitted messages from the outset negates this “break-in” period argument.
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“It uses existing arbitration IDs”: If the Nitro OBD2 were attempting to inject messages using arbitration IDs already used by the car’s ECUs, it would be a highly reckless and disruptive approach. This would likely interfere with the car’s normal operation and trigger error codes. Furthermore, it would still require a CAN transceiver, which we’ve proven is absent.
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“It relies on broadcast messages”: While passively listening to broadcasted CAN messages is possible, interpreting and acting upon them to “reprogram the ECU” for any car model would require an impossibly vast and constantly updated database of CAN protocols and vehicle-specific data. Even then, without actively querying standard OBD2 PIDs to gauge driving habits (throttle position, speed, RPM, etc.), the device would operate blindly, rendering any “performance optimization” claims nonsensical.
Ultimately, the undeniable lack of a CAN transceiver within the Nitro OBD2 hardware is the most compelling evidence. Without the fundamental hardware to transmit data onto the CAN bus, the device’s claims of ECU reprogramming and performance enhancement are simply unsubstantiated.
Conclusion: Save Your Money, Invest in Fuel
Our rigorous reverse engineering process, encompassing PCB analysis, CAN bus monitoring, and chip decapitation, leads to an unequivocal conclusion: the Nitro OBD2 dongle is a fake. It does not communicate on the CAN bus, lacks the necessary hardware for ECU reprogramming, and functions merely as a placebo device with blinking LEDs.
As one astute Amazon commenter succinctly put it: “Save 10 bucks, buy some fuel instead.” We wholeheartedly concur. Instead of investing in such deceptive products, we encourage our readers to seek genuine automotive performance enhancements through reputable tuners and verifiable modifications. Understanding the underlying technology, as we’ve demonstrated here with OBD2 systems and CAN bus analysis, empowers consumers to make informed decisions and avoid falling prey to misleading marketing tactics in the automotive aftermarket.
