The Innova 3120 Obd2 scanner has become a popular tool for both DIY enthusiasts and professional mechanics, offering a range of diagnostic capabilities in a handheld device. Recently, concerns have been raised regarding its performance with specific older vehicle models, particularly the 94 and 95 F-body cars. This review delves into a hands-on examination of the Innova 3120, specifically focusing on its OBD1 functionality with these classic F-cars. We aim to provide a comprehensive understanding of its capabilities and limitations, ensuring you have the information needed when considering the 3120 obd2 scanner for your automotive diagnostic needs.
Unboxing and First Impressions of the 3120 OBD2 Scanner
Upon receiving the Innova 3120, the packaging immediately suggests a well-organized and portable tool. It arrives in two durable black zippered plastic cases. One case neatly contains the handheld scanner unit and the OBD2 cable, while the second houses the OBD1 cable and various adapters. The inclusion of batteries is a welcome addition, allowing for immediate use. A quick start manual is also provided, though it is notably brief, directing users to the Innova website for the complete, downloadable manual.
The scanner itself is reminiscent in size to a large television remote control. It features a connector at the top for cable attachment, accommodating both the single-piece OBD2 cable and the generic OBD1 cable with interchangeable adapters. The display is a clear, blue backlit LCD monochrome screen capable of showing approximately ten lines of data at once. Navigating the device is done through nine push-button controls and three LED indicators.
Initial interaction with the button interface reveals a somewhat less intuitive design. Navigation primarily relies on UP and DOWN buttons. In menus with multiple selectable items, reaching options in the middle can become cumbersome due to the number of button presses required. Adding to this, the DTC (Diagnostic Trouble Code) display screen utilizes only a single DOWN navigation button, while the standard UP and DOWN buttons are repurposed to scroll through potentially lengthy DTC descriptions.
OBD1 Testing on 94-95 F-Cars: Unveiling Compatibility Issues with the 3120 OBD2 Scanner
This review specifically focuses on the Innova 3120’s performance with OBD1 systems found in 94 and 95 LT1 F-cars. For comparative analysis, established diagnostic tools like a Tech 2 clone and the Scan9495 PC application were used as benchmarks.
Unfortunately, tests revealed significant issues with the Innova 3120’s OBD1 functionality on these targeted vehicles, despite the scanner’s vehicle compatibility list suggesting support. When connected to an LT1 PCM bench test system with no pre-existing trouble codes, the 3120 incorrectly reported a series of fault codes: 45, 44, 43, 42, 41, 55, 54, 53, and 52. While each code was accompanied by a corresponding description, these were all false positives. The expected result was a “No codes” indication. Further testing involved introducing a genuine trouble code (code 22) into the PCM. In response, the 3120 displayed an additional, incorrect DTC 34, compounding the initial misreadings.
To investigate further, a data sniffer was employed on the data line. This confirmed that the scanner was indeed sending correct data requests, and the PCM was accurately returning data. The problem clearly resided in the 3120 obd2 scanner’s interpretation of the received data. Extensive experimentation followed, involving cycling through virtually every available vehicle setting for model years 1993, 1994, and 1995, in an attempt to find a compatible vehicle profile that would yield correct readings for the 94/95 F-car.
The investigation uncovered that the Innova 3120 was erroneously applying the data interpretation profile intended for 4.3L (LB4), 5.7L (L05), and 7.4L (L19) engines found in Type C, K, G, and P light/medium duty trucks (data-stream definition A219). Every piece of data related to several forced DTCs on the test bench correlated directly to the incorrect DTCs displayed by the scanner, aligning perfectly with the truck profile’s fault code definitions. For instance, the bit representing the Heated Windshield Request ON/OFF in the 94 F-car’s data stream was being misinterpreted as DTC 45, which corresponds to a different parameter in the truck profile.
However, this cross-referencing approach proved limited. Only about ten DTCs could be reliably correlated due to the presence of extraneous information interspersed with the DTC data that did not align with the data structure used for the truck vehicle profiles. Consequently, creating a comprehensive DTC conversion table as a workaround would be impractical and of limited utility. Further investigation into alternative solutions or compatible vehicle selections within the scanner’s menu is warranted.
It is important to note that the appearance of error codes beyond the initial nine false codes might occur due to the dynamic nature of certain data bits in the stream. For example, the gearshift selector position can influence the displayed DTCs, leading to variable and potentially misleading readings.
Limitations in Erasing Trouble Codes on OBD1 Systems
Another significant limitation identified during testing is the Innova 3120’s inability to erase trouble codes on 94/95 F-car OBD1 systems. When attempting to clear codes, the scanner simply displays an instruction to follow the vehicle manufacturer’s recommended procedure, typically involving manual methods like fuse removal or battery disconnection. This contrasts with the expected functionality of a diagnostic scanner, which should ideally offer code clearing capabilities.
OBD2 Functionality: Awaits Further Evaluation
While the OBD1 testing on 94/95 F-cars revealed substantial inaccuracies, the OBD2 functionality of the Innova 3120 is anticipated to be more reliable. However, a comprehensive evaluation of its OBD2 performance is yet to be conducted and will be a crucial next step in fully assessing the scanner’s overall utility.
Conclusion: Innova 3120 OBD2 Scanner and 94-95 F-Car OBD1 Compatibility – Proceed with Caution
In conclusion, while the Innova 3120 OBD2 scanner presents itself as a versatile diagnostic tool, its OBD1 performance on 94 and 95 F-body cars is demonstrably flawed. The scanner’s misinterpretation of data, resulting in false and incorrect diagnostic trouble codes, renders it unreliable for accurate OBD1 diagnostics on these specific vehicle models. Furthermore, its inability to clear OBD1 codes on these cars further limits its practicality. Users considering the 3120 obd2 scanner specifically for 94 or 95 F-car OBD1 diagnostics should be aware of these significant limitations and exercise caution. Further investigation into potential workarounds or alternative compatible vehicle profiles within the scanner is needed. Future testing will focus on evaluating the accuracy and reliability of its OBD2 functionality.
