2007.5-2010 GMC Duramax LMM Digital Monitors

What a monitor shows on a 2007.5-2010 Sierra HD

Picture a loaded Sierra 3500HD on a long pull. The SLT dash reports transmission temperature and the oil-change notification, with a voltmeter and oil pressure alongside, and that is where the factory information stops. A plug-in monitor like the Insight CTS3 84130-3 adds the rest: boost from the variable-vane Garrett turbo, rail pressure from the CP3, engine load, and, with an added probe, exhaust gas temperature. It is a five-inch plug-and-play display for 1996 and newer OBD-II trucks and it covers the LMM, so the install is a plug under the dash and a decision about where to put the screen. On a particulate-filter truck like this one, the readings also let you tell when the controller is running a regeneration and raising exhaust temperature on purpose.

Monitoring without touching the calibration

Monitor-only devices do not tune. They listen to the bus, do the math and draw gauges, which makes the Insight line the straightforward pick when the truck is staying as GM built it. Edge's monitor-only range runs from the CS2 84030 to the five-inch CTS3, both covering the LMM. The Evolution CTS3 looks similar on the dash and reports an overlapping set of values with data logging and speedometer correction, but its purpose is calibration, and calibration work on a registered truck belongs with a CARB Executive Order number behind it. Those are two different purchases. Buy gauges when you want to see; buy calibration only when you actually intend to change how the truck runs.

What we carry

Here you will find the Edge Products Insight CTS3 84130-3, the universal OBD-II monitoring display that reads your LMM through the factory port. Probes and senders are listed on the Accessories page beside this one, and the pillar mount that holds a CTS3 sits with the rest of the digital monitors section. For everything else on the engine, see Duramax.

Fitment notes

The OBD-II port is identical across Work Truck, SLE and SLT Sierras, Regular, Extended and Crew Cab bodies, both box lengths, and 3500HD trucks with single or dual rear wheels, so a plug-in monitor is one of the few parts on the truck that does not hinge on configuration. What does matter is the engine behind the badge: the 2007 Sierra HD Classic is the GMT800 body with the LBZ, and the LMM only came in the GMT900 HD body from mid-2007 through 2010, after which the LML took over. Mounting hardware comes with Edge monitors and no LMM-specific mounting problem is documented. Verify by VIN before ordering.

Frequently asked questions

Will this fit a 3500HD dually and a Crew Cab the same way?

Yes, as far as the monitor is concerned. It plugs into the OBD-II port, which is common to every cab, box and rear-wheel configuration in these years, and the only configuration-sensitive piece is the mount you choose for the screen.

Can I move the monitor to another truck later?

It is built for 1996 and newer OBD-II vehicles, so the display itself is not locked to the Sierra. Mounting hardware and any added probe are vehicle-specific, so check those separately on the fitment checker for whatever the next truck is.

Does the monitor reprogram anything on my Sierra?

No. Monitor-only devices do not tune, which is why owners who want their engine controller left alone choose the Insight line. If you later want calibration work, that is a separate product and it should carry a CARB Executive Order number.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.