Chevy OBS Truck Gauges With Dakota Digital’s BIM Module

In today’s ever-evolving automotive landscape, technology has rapidly transformed how we interact with our vehicles far beyond what was available when the Chevy OBS (Old Body Style) truck rolled off showroom floors. The desire for more control, improved accuracy, and seamless integration has led to innovations in automotive instrumentation. Dakota Digital’s cutting-edge products have been at the forefront of this revolution and the company’s Bus Interface Module (BIM) expansion module helps pave the way. 

Dakota Digital OBS Chevy truck gauges

The Dakota Digital gauges came with everything to begin integration with our Edelbrock ECU in our Chevy OBS truck.

Dakota Digital BIM Cures Our Chevy OBS Truck Gauge Issue

We recently acquired a 1990 OBS Chevrolet truck with a Turbo 400, LS swap, and an Edelbrock PRO FLO 4+ ECU. The Chevy OBS truck’s factory gauges have been removed and replaced with a mod podge of less-than-accurate gauges and toggle switches. And although we had the factory gauges in our possession, there wasn’t a great way to make them communicate with the Pro Flow 4+ ECU. But to our surprise, Dakota Digital has a system, including the necessary BIM module to allow our gauges to seamlessly communicate with the PRO FLO 4+ ECU in our Chevy truck.

Our Chevy OBS truck did have gauges, but their accuracy was questionable at best. And, imagine trying to decipher a wiring diagram comprised of only red wires. Who does that?

If you’ve ever done an engine swap or added fuel injection to a previously carburated vehicle, you probably know the factory gauges are usually an issue. It can be challenging to get them to integrate properly with modern technology. So, what are your options? You can double-up on the sensors and have one for the gauges and the other for the ECU, go without gauges altogether, or the best option is to replace them with state-of-the-art units. While the first two options are doable, we prefer the latter, and Dakota Digital has made gauge integration into our Chevy OBS truck seamless, even with a modern ECU, with a device they call a Bus Interface Module or BIM switch. 

Dakota Digital BIM module for Edelbrock EFI

Dakota Digital offers several different BIM modules designed to allow its gauge sets to communicate seamlessly with various ECU manufacturers. This one is designed to transport engine parameters from our Edelbrock EFI system.

BIM switches are critical to modern automotive instrumentation. They serve as the bridge between the vehicle’s ECU and the driver, allowing for seamless and intuitive interaction of data. “The BIM module is communicating with the ECU much like a scan tool,” Dakota Digital’s Scott Johnson explains. “Rather than making individual connections to each sensor, the BIM models request specific gauge-related data from the ECU.”

Rather than making individual connections to each sensor, the BIM models request specific gauge-related data from the ECU. – Scott Johnson, Dakota Digital

Precision & Versatility Of BIM Switches

One of the standout features of Dakota Digital BIM switches is the precision they offer when interfacing with your vehicle’s gauge systems. Unlike traditional switches that often rely on mechanical components that can wear out over time, BIM switches are digital and use advanced technology to provide precise, reliable control. You can expect consistent and accurate operation, further enhancing your overall driving experience.

Dakota Digital BIM switches are versatile and can be integrated into various vehicles, from classic cars to modern rides. This adaptability is a game-changer for car enthusiasts who want to retain their classic cars’ aesthetics while enjoying the benefits of modern technology. With BIM switches, you can replace or augment existing instrumentation, giving your vehicle a contemporary edge.

In the case of GM ECUs, the BIM series of modules is compatible with 1996 and newer applications. This is a direct result of the implementation of the OBD II standard. As CAN communication became more prevalent in the mid-2000s, the increased amount of data available led to additional gauge-related readings available to access and display.

Custom Gauges For Our Chevy OBS Truck

One of the most significant advantages of Dakota Digital BIM switches is their high degree of customization and personalization. With these switches, drivers can tailor the given information to their preferences. This level of customization is especially beneficial for car enthusiasts who want to fine-tune their driving experience with diagnostics at a moment’s notice

Dakota Digital digital message board information

While the technology behind BIM switches is advanced, Dakota Digital ensures the interface is user-friendly with plug-and-play simplicity. This makes installation a breeze, even for less tech-savvy people.

As most know, modern vehicles generate a vast amount of data, and Dakota Digital’s BIM switch allows drivers to access and interpret this information even with an older car. These switches can be integrated with vehicle data sources to display real-time information that is displayed right on the gauge panel. 

BIM module integration with the LS/LT platform offers some great benefits. The first is to reduce and simplify the complexity and amount of wiring. Rather than installing separate oil pressure and water temperature sensors, this information is now available directly from the vehicle’s ECU. This can greatly reduce installation time overall, and considering hourly shop rates, this can translate to a reduced cost right off the bat. 

Additionally, the standardization of sending units simplifies any troubleshooting in the future. For example, if the GM oil pressure sensor is the source of this reading, there is no variance in this value from the ECU to the gauge. A scan tool will mirror the results shown on the gauge. If a GM sensor fails while on a road trip, replacement sensors are readily available from a parts store or dealer. Fewer installed sensors reduce the potential for leaks, reduce the wiring in the engine compartment, and provide more consolidation.

Our OBS Chevy we are upgrading is a 1990 454SS. The allotment of gauges being utilized was not the best, so we decided to replace them. Don’t worry; we’ve seen the price of the factory units, and they have been stored in a safe place. We opted for Dakota Digital’s HDX instruments for the 1988-1994 Chevy/GMC OBS trucks. The company offers the set in two gauge face colors: Black Alloy and Silver Alloy. 

Gauge & BIM Installation

Here are the factory OBS gauges compared to the Dakota Digital HDX gauges. The HDX gauges look better, and display a lot more information via the BIM module, thanks to the digital display in the center of the cluster.

Thanks to the simplicity of the plastic interior, installing the HDX gauges is easier than installing other year gauge clusters. With the gauges securely mounted in the dash, we turned our attention to the wiring and BIM switch installation. 

First, we mounted the HDX control box and BIM switch in the glove box. Let’s face it, this storage area is only helpful if you ditch technology and return to a paper, foldable road map.

The glove box is small in these trucks and not much use for anything. However, it's the perfect size for electronics. 

After we mounted the BIM switch and the gauge module, we moved to the wiring. The HDX box tells you where each wire goes, and if you have questions, Dakota Digital provides a very informative user manual with instructions, too. Next, it was time to wire the BIM switch so the gauges could pull data from the PRO FLO 4+ ECU. 

Dakota Digital BIM module connected to Edelbrock ECU

BIM switches are simply plug-and-play into the designated harness to allow the dissemination of a wealth of information within the ECU.

You might think there’s a lot involved when installing a BIM switch since it will input RPM, water temp, intake air temp, fuel pressure, air-fuel ratio (AFR), manifold air pressure (MAP), and even boost. However, that’s not the case. You simply plug in a couple of wires, and that is it; the BIM module will do the rest. 

And, since more data is available from the ECU than even the standard six gauge readings that we’re all accustomed to, a variety of extra data can be available for display within the onboard digital Message Centers. Examples could be for intake air temperature, transmission temperature, ambient air temperature; even the gear position, or manually selected gear in some cases.

The HDX gauges have a modern, factory feel that is a welcomed upgrade in our OBS Chevy truck.

With our gauge installation complete, we can now turn our attention back to the LS swap. Unfortunately, the engine’s installation was done as haphazardly as the instrumentation in this truck. So, while Dakota Digital made quick work of data acquisition issues on our OBS, we still have some work to do before this beast is ready for the streets. But in the meantime, you can read more about the HDX gauges and their functionality HERE.

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Brian Havins

A gearhead for life, Brian is obsessed with all things fast. Banging gears, turning wrenches, and praying while spraying are just a few of his favorite things.
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