Possible issue using M2RET with benches but not cars

[redheadedrod]

I will post this here…

Going to verify later in vehicle to insure it is still working there but I can not get my M2’s working in my lab. I get giberish from them both.

I have two ET7190’s talking back and forth making a data stream and I can see it fine from my STN based dongle.

I have tried it with no resistors between the canbus lines which ended up with nothing communicating… With 1 120 ohm resistor across the canhi and canlo lines. And I have tried it with 2 120 ohm resistors across the canhi and canlo. Still not getting anything but giberish. And the STN dongle sees it fine. I use the same plug for my M2 UTD module as the STN dongle. My M2 UTH is hard wired to the same lines as the ODB port.

Again I will verify that it is still working in my vehicle. If this is the case I am not sure how to proceed in relation to the M2 as I can not test it with my lab with the CANBUS stuff.

Have tried it with a known working SavvyCAN installation and I downloaded Collins latest binary update and SavvyCan. The SavvyCAN appears to be connecting to the M2 and shows 2 canbus ports but is not showing any data.

Will try it in the morning in my vehicle and see what it does there.

Rodney

[redheadedrod]

@josh I have now verified that there is something fishy with the M2 CANBUS connection.

While it seems to be working in car it is NOT working with the lab I have setup.

I am posting here because it looks like there is an issue when not used in car with the M2.
When I use it in my vehicle it works great.

My Lab has two ET7190’s tied together on one side of a terminal strip connection. The other side is tied to an ODBII port and a hardwired connection for the M2 UTH.

WIth the UTH NOT connected and nothing connected to the ODBII port I have to add a 120 OHM resistor between the two canbus ports to get the ET7190’s talking to one another.

With them talking together I can monitor with an STN based ODBII cable. I have Scantools ODBII SX cable which does not have the SWCAN port but has everything else.

If I connect my M2 UTD to the same ODBII port as used and verified with the STN cable the M2 only shows jibberish on the serial monitor and doesn’t work at all.

Same issue shows its head with the M2 UTH which is wired in parallel.

I have added a second 120 ohm resistor in Parallel with the first and the ET7190’s still talk fine and the STN will talk fine. M2’s still Giberish.

What do you suggest I try next?

Note that the VPW connection works with both models of the M2 so I know they are getting power etc…

SavvyCAN doesn’t show anything on it and if I just open up the serial monitor at the required 115k baud it is just giberish that looks like a bad connection or baud rate. I tried all of the baud rates supported by the monitor and the data looks the same.

Things I have NOT tried yet but could include disconnecting all of the lines but the Grounds, +12 and the CANBUS, or adding more resistors.

Since it appears someone else in this thread is having an issue with their lab it is possible this is will be a common issue that we need to figure out?

Thanks. Can’t do any more testing today, on my way to work.

Rodney

[redheadedrod]

Wow, got home tonight and hooked up my M2 to the lab and it worked… I have NO idea how that happened…

Only thing that was different was the USB cable.

I am at a loss now…

The weirdest thing because I was able to flash both of my M2’s fine… And VPW worked fine but CANBUS did not.

Wondering if maybe the cable I was using was subpar quality and the high speed of the CANBUS was picking up noise?
I would think if it didn’t work with the CANBUS it shouldn’t have worked when flashing either.

Very weird… Unless the Windows Update that happened this week changed something in both machines that made it suddenly start working.

Ok then… So I can get back to where I wanted to do stuff…