2007 GMC Acadia canbus problem

2007Acadia with a canbus problem, traction light stability light off and problem on the DIC, intermittently , communication with scan tool ,dtc u2100 ohms 52.1 which is a little low. my question is can anybody give me direction on what the possible meaning of this waveform thank you?

jerry r, let's back up a second. Which module is setting the U2100, specifically? The EBCM?

Your thread title says 2007, but the message says 2017. U2100 is a possible DTC on both.

Where did you take your 52.1 ohm measurement? 6/14 at the DLC? Was the problem happening while that measurement and your waveform were taken?

It's a 2007 the dtc is on the bcm and ecbm resistance test between 6/14 checked with battery unhooked,waveform tooken at 6/14 vehicle running

I'm wondering if that sine wave in your channel settings means the 'scope is set to AC instead of DC??

Trying to reply from laptop with a link copy/paste but don't know why it won't allow me to right click and paste or other paste methods. Any clue as to why this occurs even on mobile browsers as well @Tyler

Dtnel wrote: Trying to reply from laptop with a link copy/paste but don't know why it won't allow me to right click and paste or other paste methods. Any clue as to why this occurs even on mobile browsers as well @Tyler

The website disables right click when you're logged in. If I want to copy text or images from a thread I open it in a private window. Copy and pasting when replying I use keyboard shortcuts.

It's on DC this is happening intermittently

Dtnel wrote: Trying to reply from laptop with a link copy/paste but don't know why it won't allow me to right click and paste or other paste methods. Any clue as to why this occurs even on mobile browsers as well @Tyler

Matt T nailed it. It's a spam control feature built into Kunena. It's annoying, we know.

Keith Perkins in his youtube video Diagnostic Process Round Table mentions he doesn't like anything less than 54 ohms so maybe start with that. The resistors are in ECM and the Transfer Case Shift Module or if you don't have that, a standalone resistor hanging out of the harness. Might as well just pull the AWD (transfer case) fuse 15A in the underhood fuse block and work through each module on the canbus, killing power, to shut them up lol.

See if this video I stumbled across the other day can help you. He laid it out in layman terms & pretty good for a young guy to boot.





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Bothe of those waveforms were on the High / Low Can Bus Channels? The reason I ask is you'll have networks that do the same thing at times and the waveforms will be identical showing they're communicating properly.

Did this have a code? GM Traction Control, Service 4ed lights have always been a "normal" visitor. I chased one a few years ago on my 2004 Tahoe with Code, thought it was the Switch after checking wiring, harness plugs, transfer case shift motor. Swapped the switch, ran fine for a couple years

Yes on low and high can I checked before on this vehicle and they were mirrored each other not identical ,6/14 on dlc

Yea that waveform doesn’t mirror each other. More like there almost the same both go high both go low.

What modules do you lose communication with when the waveform looks like that? The whole can bus or just one module?

Everything the whole bus vehicle still starts but acts like it's misfiring,and gauges go a little crazy when I hook up the scanner when there's no communication koef

Yea you might want to pull power to one module at a time. Or unplug module use jumper wires to jump com lines coming in and going out of module.