HOWTO: Daisy-chained AEM Serial Gauges w/ Series 2 EMS

[Intropy]

Alright, I'm going to do a guide on something that is awesome and yet poorly documented for some reason. As you know, by connecting an AEM 30-4300 serial gauge to your EMS, you have a customizable gauge that can be set up to view just about any parameter as seen by the EMS. Actually, you can do a lot more than that. When I started this project, I didn't realize just how powerful this combo really is.

The good news is that the gauge also works great with the series 2 EMS. As an added bonus, since the s2 has a USB port, you can leave the gauge connected all the time. There's no need to swap between your laptop's serial connection and the gauge.

It gets even better. You can daisy-chain serial gauges and configure each gauge separately, creating a cluster that can be programmed to show different parameters based on conditions. For example, here are my two serial gauges, displaying front bank and rear bank AFR:



This will be an ongoing, multi-part howto, covering every aspect of installation, setup of the EMS, gauge setup, and customization. It will probably take me a couple weeks to document everything, so be patient. Feel free to ask questions along the way, I'm not worried about keeping the thread "clean".

What do I need to begin?
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Well, you need the AEM EMS and as many serial gauges as you want to hook up. That's it - the gauges come with the daisy-chain harness and everything. I did not, in AEM's documentation, see any hard limit on the number of gauges you can connect. I know you can do at least three, and I'm assuming more.

Now is also a good time to think about any accessories you want to hook up. Yes, I said accessories. The gauges themselves can each activate two accessories, which are of the on/off variety and draw 1A max. This is pefect for warning lights, shift indicators, etc. Of course the AEM itself can also do this, but it may be convenient to wire the light to the gauge. For example, my gauges are located in the A-pillar, so wiring a warning light to the top of the dash would be a snap.

To be continued...