First let me say I love the ScanGauge.
I own three of them. My dad and brother have them too.
Overall it is a great product at reasonable cost.
I had one, then later two daisy chained together in my FEH since 2006.
I have had them plugged into the car, a 2005 FEH continuously 24/7/365 for close to 8 year. Sun - heat - sub zero, just about 150,000 miles.

In JANUARY and FEB of this year I would get a "Stop Safely Now" message along with "Service Regen System" and the car would "die". Turning the key off for a few seconds and restarting always got me home.

First it was once every three days.
Then every other day.
Then daily.

About at my wits end because I LOVE THIS CAR!
I tried using the SG to catch codes but there were no codes. Ever.
THEN I started noticing characters missing from the SG display.

I unplugged both Scangauges and HAVE NOT HAD A SINGLE SHUT DOWN OR ERROR MESSAGE SINCE!!!!!

Not wanting to jump to conclusions I waited 6 weeks and over 3,500 miles before posting here.

I do not know if the "program" went bad in the SG or if it was something mechanical like a broken or shorted wire. ALL I KNOW IS the moment the ScanGauge was removed my car went back to normal.

Now that I'm confident my car is OK I will plug in a single SG to find which one was faulty. And toss the other out.

whew! I feel like I dodged a bullet here. Just FYI in case someone else gets similar symptoms.

What have we learned? Not surprisingly, bad data in the CAN data network inside the FEH can stop the car. Even when everything mechanical is A-OK.

-John - now at over 10 years and 182,000 miles.

 

I can see that happening.

Way back before DesertDog was run out of this forum and I got my SG-II, he was guiding me through something. Sent out some command and it came back with some odd response. I thought, all that data flying could be a problem.

I always thought having multiple SG-II "could" be an issue.

I have read about severe problems when using just one on much older vehicles.

 

I had a similar problem last fall. I didn't have a Scangauge, but I had a Mobileye C2-270 driver assistance unit.

The symptom was that all of a sudden, the TPMS warning would come on. Cancel it, and a door ajar warning, cancel that and some other warning. Etc. The turn signal lights worked but there was no audible "click". The radio was completely dead. And the Mobileye itself was malfunctioning.

It drove my service garage nuts trying to find the problem. We replaced the 12V battery even though it was good enough.

The problem persisted until I unplugged the Mobileye. Everything instantly back to normal. Since the unit was 6 months out of warranty, Mobileye wouldn't cover it. The only alternative was to have a new Mobileye 560 installed at a total cost of about $1300. So I gave that a pass.

I did keep the broken Mobileye, and some troubleshooting tracked the problem down to being most likely a defective interface between the Mobileye logic unit and the CAN bus. So they can talk to each other. It seemed the Mobileye was either generating bogus CAN packets which were interpreted as commands, or spraying static onto the CAN bus.

According to my reading of the FEH's CAN network, it has two portions. One is a medium speed network that controls pedestrian stuff such as lights and the entertainment system. The other is a high speed network that controls the engine and various other critical controls. The two networks are very separate.

The Mobileye was wired into the medium-speed bus, so it should not be able to affect the critical systems. The SGII, with a bigger appetite for data, probably connects to the high speed network and so may be able to be a serious problem. This can be figured out from the FEH's wiring diagrams and knowing what wires the SGII uses.

 

Funny you mentioned turn signals with no click. I had 4 way hazard flashers go off with no click. At random. Without the key in the ignition some times!

I always thought the flasher and the click were on the same wire as in old days. Guess not.

Why would you go through the effort to have something like that on a data network?
Now cars are on the Internet and you can control systems in your car, including brakes and ignition from a remote location.

Soon cops will be able to stop your car from their car. Electronically.

 

The Mobileye warns of unsignaled lane changes and forward collision risk. To do this it monitors the CAN bus for signals for speed, throttle position and change, brake application and turn signal activation. It even connects to the windshield wiper wiring to add warning time using the wipers as an indication of bad weather and wet pavement. This allows it to make a very sophisticated calculation about the timing and urgency of warnings.

While I share your concerns about control and privacy, I think it would be great to eliminate high-speed car chases by being able to disable cars using electronics. Far too many innocent people have died in these chases.