Strange Autel MaxiSYS Ultra can bus problem
I wanted to share this strange issue I ran into the other day while trying to scan this Tahoe. The vehicle came from a collision shop that was trying to fix an air suspension issue. I connected the autel and noticed it would not detect the VIN, so I entered the vehicle info manually. When running a system scan the tool could not communicate with the ECM and most modules on the high speed bus would set a U0100: Lost communication with ECM. The gauges also started acting erratically, but would start working normally when the tool was disconnected from the DLC.
At this point I decided to try running a scan with a different scan tool (Snapon Zeus). The zeus was able to communicate with the ECM, the gauges did not act erratic, and all of the communication codes changed from current to history. I tried connecting the autel again but it would cause the same issues as the first time. I took two captures of the bus, one while running a system scan with the autel, and one with the zeus. The autel capture seems to have some odd bus activity, but I'm not really sure.
Two days ago, I was able to use the autel on a 2008 Tahoe hybrid without issue. I have yet to test it on another GM of this era. The tool is up to date, I'm not sure if there was a update recently that is causing this issue. Has anyone else seen something like this before? I was about to chase this until I realized the collision shop made no mention of an issue like this, and it was only happening with the scan tool connected.
My 906BT did that last week; Updated everything offered and issue then stopped with GM scannings.
Hi John, I found out firsthand on my ‘95 Ford F-350 diesel shop truck, that the 906BT freaked out. As it turned out the BAUD rate was the issue. In ’95 Ford was just transitioning their computer systems along with many other manufacturers at the time. Just the same though, the 906BT is my daily go to scanner, but it is not bullet proof or the one size fits all tool.
I just ran into an issue a couple days ago with my up to date Autel, I forget the model, that it would not detect the VIN, and like yours, it would not communicate with all the modules. That was on a 21 ford escape. Snap-on tool communicated just fine. I don't know that the Autel affected the CAN communications however.
Hi Charles, I wonder if the Autel being used is a U.S. model or a rogue copycat/other country version from Amazon. Autel USA in New York can verify this info. They may also be able to provide a push update to correct the issue. They don't know unless they are made aware of problems. They have helped me a couple of times. Update: Gee, I got down voted? I am not unprofessional for pointing out…
I posted a thread elsewhere on here about a similar issue with a 2008 Trailblazer, where the Autel (both an Elite and an old MS808) would actually screw up the can buss and cause all kinds of weird and erratic behavior, even losing contact with the ECM and TCM. There are just some strange baud rate issues with some of the high-speed interfaces. TechII has no similar issues, seemingly.
Older Autel maxisys elite would not communicate with 2020 Silverado, although I had up to date software on my Autel. Worked fine on multiple 2015 GM’s I had. Launch scanner worked on 2020 truck. Ended up updating my VCM and everything worked fine. Give that a try.
I think there was a recent VCI update for some Autel scanners. Do you remember doing that and if it was after?
Yes, there was, I started to get a pop-up message in order to use my device to update it and the VCI manager loaded.
Yeah I did do that update, it was actually the first time I remember getting notified to update the VCI. After the update I noticed it would go through a system scan significantly faster on some makes. I will probably contact autel support if something like this happens again.
I had it do something similar, but on my own personal 2019 Honda. What had happened was I would plug in to OBD, immediately the car started throwing codes, breaks, air bags, everything! It was a short in the Reflasher! You may be experiencing something similar.
Anytime you run into an issue like this make sure to submit a report to Autel or whatever scan tool you are using. The Autel tools have a button on the top right corner for doing this, so that Autel knows about it and can fix the issue for everyone. I had a similar issue with a late model Lexus and after submitting the report, Autel support had it fixed same day.
This may be a difference in the way the scan tool picks up the ground through the DLC. Both scope traces show a shift in the “at rest” voltage of 2.9 - 3.0 volts (should be 2.5 volts). The DLC provides ground at terminal 4 and terminal 5. If you have a DLC breakout box, try reading with the Autel again while jumpering pins 4 and 5 at the breakout box. If it reads the high-speed LAN correctly…