The Innova 3120 handheld scanner has been gaining popularity, but recent user feedback has raised concerns about its performance with 94 and 95 GM F-body cars (Camaro and Firebird). Prompted by these reports, we decided to conduct a hands-on review of the Innova 3120d, specifically focusing on its OBD1 compatibility with these classic vehicles. Our findings reveal some critical shortcomings that potential buyers need to be aware of.
First Impressions and Initial Setup
The Innova 3120d arrives in two practical black zippered cases, neatly separating the handheld unit and OBD2 cable from the OBD1 cable and adapter set. The inclusion of batteries is a plus, although the accompanying manual is notably brief, pushing users to download the comprehensive manual from Innova’s website. Connecting the cables to the scanner head is straightforward. The OBD2 cable is a single, unified piece, while the OBD1 cable is a generic type designed for use with various adapters.
The scanner features a blue backlit monochrome LCD display, capable of showing approximately 10 lines of data at a time. Navigation is managed through 9 buttons and 3 LED indicators. The size of the unit is comparable to a standard TV remote, making it reasonably portable.
However, the button interface presents some usability challenges. Navigation relies solely on UP and DOWN buttons, which becomes cumbersome when scrolling through lengthy lists of options. The DTC display screen further complicates matters with only a DOWN navigation button; the regular UP and DOWN buttons are repurposed for scrolling through potentially lengthy DTC descriptions.
OBD1 Testing on 94-95 LT1 F-Cars: A Disappointing Outcome
For this review, we concentrated on evaluating the Innova 3120d with OBD1 systems in 94 and 95 LT1 F-cars. We benchmarked its performance against a Tech 2 clone and Scan9495 PC application, tools known for their reliability with these vehicles.
Unfortunately, the Innova 3120d does not perform adequately with these specific car models, despite being listed as compatible. When connected to our LT1 PCM test bench, which had no trouble codes present, the scanner incorrectly reported a series of false DTCs: 45, 44, 43, 42, 41, 55, 54, 53, and 52. Each of these phantom codes was accompanied by a description, further suggesting a misinterpretation of the data. In a controlled test, we introduced a trouble code 22 to the PCM. Instead of accurately reflecting this, the 3120d added a DTC 34, again, an erroneous reading.
Further investigation using a data sniffer on the data line confirmed that the Innova 3120d was sending correct data requests, and the PCM was responding with accurate data. The issue clearly lies in the scanner’s incorrect interpretation of the received information. Extensive testing across various settings for 93, 94, and 95 vehicle years revealed that the 3120d was mistakenly applying data definitions intended for 4.3L (LB4), 5.7L (L05), and 7.4L (L19) engines in Type C, K, G, and P light/medium-duty trucks (data-stream definition A219).
The incorrectly reported DTCs directly correlated with data points in the truck data stream. For instance, the bit representing the Heated Windshield Request ON/OFF in a 94 F-car was misinterpreted as truck DTC 45. While approximately 10 DTCs could be cross-referenced in this manner, creating a comprehensive workaround conversion list is impractical due to data inconsistencies beyond these initial points. The presence of other information mixed with the DTC data, incompatible with other vehicle types, limits the effectiveness of such a solution.
It’s also worth noting that the erroneous DTC readings can fluctuate based on factors like gearshift selector position, as the data bits in these locations can represent different vehicle parameters.
Another significant limitation for 94-95 F-car owners is the Innova 3120d’s inability to erase trouble codes in these vehicles. Upon attempting to clear codes, the scanner simply instructs the user to follow the manufacturer’s procedure, which typically involves disconnecting the battery or pulling a fuse.
OBD2 Operation: To Be Evaluated
While our testing focused on OBD1 performance, the manufacturer claims more accurate OBD2 operation. We plan to evaluate the OBD2 capabilities of the Innova 3120d in future tests to provide a more complete picture of its overall performance.
Conclusion: Exercise Caution for OBD1 94-95 F-Cars
Based on our findings, the Innova Obd2 3120d scanner exhibits significant inaccuracies when used with OBD1 systems in 94 and 95 GM F-cars. The misinterpretation of data, leading to false DTC readings and the inability to clear codes, makes it unreliable for diagnosing issues in these specific vehicles. While OBD2 functionality may be more dependable, owners of 94-95 Camaros and Firebirds seeking an OBD1 diagnostic tool should exercise caution and consider alternative scanners known for their compatibility with these classic GM models. Further investigation into the OBD2 capabilities is needed to provide a comprehensive assessment of the Innova 3120d’s broader utility.
