The “Nitro OBD2” chip tuning box is widely advertised as a plug-and-play solution to boost your car’s performance and fuel efficiency simply by connecting it to your vehicle’s OBD2 port. Claims suggest it can intelligently remap your engine control unit (ECU) based on driving habits. However, numerous online discussions and user reviews question its effectiveness, with many labeling it as a scam. Intrigued by these conflicting opinions, we decided to delve deeper and conduct a reverse engineering analysis of a Nitro OBD2 dongle to uncover the truth behind its performance claims.
Understanding the Context of Automotive Enhancements
Automotive security and performance modification are complex areas. Modern vehicles are sophisticated systems with interconnected networks, offering various points of interaction. Our team has extensive experience working with in-car networks, particularly the Controller Area Network (CAN bus), exploring different communication methods and device integrations. This background led us to investigate consumer-grade OBD2 devices and their purported capabilities.
A colleague brought the Nitro OBD2 device to our attention, curious about its advertised ability to optimize engine performance and fuel economy. To satisfy this curiosity and investigate the validity of its claims, we purchased a Nitro OBD2 dongle and embarked on a reverse engineering journey. This article details our findings, offering an in-depth look at the device’s internal workings and its actual impact on vehicle performance, providing a more comprehensive analysis than a typical product review.
PCB Examination: Unveiling the Internals
Before connecting the Nitro OBD2 to a vehicle, we opted to examine its internal components. Opening the dongle revealed a standard OBD2 connector interface. The pin layout was as expected for an OBD2 device:
Standard OBD2 connector pinout diagram, highlighting pins for CAN bus, J1850, and ISO 9141-2 protocols.
Our initial check confirmed that the pins associated with the CAN High (CANH) and CAN Low (CANL) signals were indeed connected on the circuit board, a fundamental requirement for any device intending to communicate via the CAN bus. Further inspection of the circuit board revealed that the active pins were those corresponding to CAN bus communication, along with legacy J1850 and ISO 9141-2 protocols. However, a closer look at the PCB layout raised immediate questions about the device’s purported capabilities:
Detailed view of the Nitro OBD2 circuit board, showing a simplified design with minimal components connected to the central chip.
Analyzing the circuit board, we identified a basic component arrangement:
- A rudimentary power supply circuit.
- A push button, likely for reset or status indication.
- A single integrated circuit (IC) chip as the central processing unit.
- Three LEDs (Light Emitting Diodes) for visual feedback.
Notably absent was a dedicated CAN transceiver chip. This absence suggested two possibilities: either the CAN transceiver was integrated directly into the main IC, or the device lacked CAN communication capabilities altogether. Considering the advertised functionality of ECU reprogramming and performance enhancement, which typically requires CAN bus interaction, the lack of a discrete transceiver was a significant red flag. The core logic for interpreting vehicle data, modifying engine parameters, and reprogramming the ECU would need to be contained within that single, small SOP-8 packaged chip, which seemed highly improbable for such complex tasks. Skepticism about the Nitro OBD2’s advertised functionality began to mount at this stage.
CAN Bus Communication Analysis: Testing for Activity
To empirically determine if the Nitro OBD2 device actively communicates on the CAN bus, we conducted a series of tests on a vehicle.
Test Setup
We chose a 2012 Suzuki Swift diesel car for our tests, as it was readily available and compatible with standard OBD2 diagnostics. This vehicle is regularly used with an ELM327 OBD2 adapter and the Torque Android application for retrieving engine data and clearing diagnostic trouble codes (DTCs), providing a known baseline for CAN bus communication.
Our testing methodology involved recording CAN bus traffic under two conditions: first, without the Nitro OBD2 plugged in, and then with it connected. To capture CAN messages, we utilized a Raspberry Pi equipped with a PiCAN2 shield and the python-socketcan-monitor tool. This setup allowed us to log all CAN bus activity via the OBD2 port.
The following diagram illustrates our initial CAN bus monitoring setup:
To ensure the integrity of our CAN bus monitoring setup, we also employed a PicoScope to directly observe the CAN High (CAN_H) and CAN Low (CAN_L) signals. As expected, the oscilloscope confirmed the presence of clean and active CAN bus signals on the vehicle’s OBD2 port.
PicoScope visualization of CAN bus signals (CAN_H and CAN_L) from the Suzuki Swift’s OBD2 port, confirming normal CAN communication.
With a verified CAN bus monitoring system in place, we proceeded to record CAN traffic with the Nitro OBD2 device connected. Since the vehicle has only one OBD2 port, we devised a method to simultaneously monitor CAN traffic while the Nitro OBD2 was plugged in. We carefully opened the Nitro OBD2 dongle and soldered wires to the Ground, CAN High, and CAN Low pins on its internal circuit board. These wires were then connected to our Raspberry Pi’s PiCAN2 interface, effectively placing our CAN bus sniffer inline with the Nitro OBD2 device.
This modified setup allowed us to intercept and record all CAN bus traffic passing through the Nitro OBD2 dongle while it was connected to the car’s OBD2 port.
Modified Nitro OBD2 device with wires soldered to CAN bus pins for simultaneous monitoring and connection to the vehicle.
Test Results: Silence on the CAN Bus
We recorded CAN bus traffic for a duration both before and after plugging in the Nitro OBD2 device. The captured CAN bus log without the Nitro OBD2 connected showed typical vehicle communication:
In contrast, the CAN bus log captured with the Nitro OBD2 plugged in revealed a striking absence of new messages originating from the device:
Comparison of CAN bus traffic logs: (Top) Normal vehicle CAN traffic without Nitro OBD2. (Bottom) CAN traffic with Nitro OBD2 plugged in, showing no additional messages.
A direct comparison of the two CAN bus logs clearly indicated that the Nitro OBD2 device was not transmitting any messages onto the CAN bus. This finding strongly suggested that the device was not actively communicating with the vehicle’s ECU or any other CAN bus modules. Instead, it appeared to be passively observing the CAN_H and CAN_L signals, likely to detect CAN bus activity and trigger the blinking LEDs, creating a false impression of activity without actually engaging in any communication.
Chip Decap Analysis: Peering Inside the IC
Having established that the Nitro OBD2 does not communicate on the CAN bus, we proceeded to analyze the central integrated circuit (IC) chip itself to further understand its capabilities. Unfortunately, the chip lacked any identifying markings, preventing us from directly referencing its datasheet. Driven by curiosity, we performed a chip decapsulation process using sulfuric acid at 200°C to expose the die for microscopic examination.
Microscopic imaging of the decapsulated Nitro OBD2 chip revealed internal structures characteristic of a standard microcontroller. We could identify areas corresponding to RAM (Random Access Memory), Flash memory, and the CPU (Central Processing Unit) core. However, there was no visual evidence of specialized embedded devices, such as a CAN transceiver, integrated within the chip’s die.
Could the designers have somehow integrated a CAN transceiver within this standard microcontroller package? To investigate this possibility, we compared the Nitro OBD2 chip to a known CAN transceiver, the TJA1050, which is a common and discrete CAN transceiver chip. We also decapsulated a TJA1050 chip and placed it side-by-side with the Nitro OBD2 chip for a comparative visual analysis:
Microscopic comparison of decapsulated chips: (Left) TJA1050 CAN transceiver, showcasing distinct transceiver circuitry. (Right) Nitro OBD2 chip, revealing a standard microcontroller architecture without transceiver components.
The visual comparison clearly demonstrated the stark difference in design and complexity between the TJA1050 CAN transceiver chip and the Nitro OBD2 chip. The TJA1050 exhibited a distinct circuit layout indicative of dedicated transceiver functionality, which was absent in the Nitro OBD2 chip. Furthermore, the die size and internal structure of the Nitro OBD2 chip simply did not appear to have sufficient space or complexity to incorporate a functional CAN transceiver alongside the microcontroller core, RAM, and Flash memory. This chip-level analysis reinforced our conclusion that the Nitro OBD2 device lacks the essential hardware for CAN bus communication and ECU interaction.
Addressing the Devil’s Advocate: Countering Potential Arguments
Despite the compelling evidence against the Nitro OBD2’s functionality, some may still raise counterarguments or express skepticism about our conclusions. We address some common points and assumptions to further solidify our analysis:
“It needs 200km to become effective”: Some users claim the device requires a significant driving distance to “learn” driving habits and optimize performance. However, our CAN bus monitoring began immediately upon plugging in the device and continued throughout a test drive. The absence of any CAN bus communication from the Nitro OBD2 from the outset directly contradicts this “learning” claim. If the device were genuinely analyzing driving habits and reprogramming the ECU, it would necessitate active CAN bus communication from the moment of connection.
“It uses existing CAN IDs”: One could argue that the Nitro OBD2 might be using CAN arbitration IDs already employed by the vehicle’s existing ECUs, attempting to blend in with normal CAN traffic. However, this scenario is highly problematic and unlikely for several reasons:
- Conflict and Disruption: Transmitting messages using the same CAN IDs as existing ECUs would inevitably lead to communication conflicts and disrupt the vehicle’s normal operation. This could cause unpredictable behavior and potentially trigger diagnostic trouble codes.
- Complexity and Vehicle Variation: To effectively mimic an existing ECU and inject performance-enhancing commands, the Nitro OBD2 would need an incredibly sophisticated understanding of the specific vehicle’s CAN bus protocol, message formats, and ECU control logic. This level of vehicle-specific knowledge is impractical to implement in a generic, plug-and-play device advertised for wide vehicle compatibility. Furthermore, CAN bus systems and ECU communication protocols vary significantly across different car manufacturers and models, making a universal “spoofing” approach highly improbable.
- Lack of Standard OBD2 Interaction: A legitimate performance tuning device would typically interact with the ECU via standard OBD2 Parameter IDs (PIDs) to read sensor data and issue control commands. Relying solely on passively monitoring broadcasted CAN messages without actively querying OBD2 PIDs would severely limit the device’s ability to gather meaningful driving data and implement targeted performance adjustments.
Considering these points, the hypothesis that the Nitro OBD2 operates by stealthily injecting messages using existing CAN IDs is not only technically dubious but also practically unfeasible and potentially detrimental to vehicle operation.
No CAN Transceiver = No CAN Communication: Ultimately, the most definitive piece of evidence remains the absence of a CAN transceiver on the Nitro OBD2 circuit board and within its central IC chip. CAN transceivers are essential hardware components required for physical layer communication on a CAN bus network. Without a transceiver, the Nitro OBD2 simply lacks the fundamental capability to transmit or receive CAN bus signals, rendering any claims of ECU reprogramming or performance enhancement through CAN communication completely unfounded.
Conclusion: Save Your Money, Buy Fuel Instead
Our comprehensive analysis, encompassing PCB examination, CAN bus monitoring, and chip-level analysis, consistently points to the same conclusion: the Nitro OBD2 chip is not a performance enhancement device. It is, in essence, a cleverly disguised placebo. It does not communicate with the vehicle’s ECU, it does not remap engine parameters, and it offers no tangible performance benefits. The blinking LEDs and the suggestive name are purely for show, designed to create a false impression of functionality.
As one insightful Amazon reviewer aptly put it: “Save 10 bucks, buy some fuel instead.” This succinctly captures the true value proposition of the Nitro OBD2 – or rather, its lack thereof. Instead of investing in this deceptive device, we recommend focusing on genuine and proven methods for vehicle maintenance, efficient driving habits, and, if desired, reputable and verifiable performance tuning solutions.
