I know a bit about these systems used by all the major manufacturers, so thought I'd share.
As most people know, the interface in a car is called OBD2, or more generally, a
DLC connector.
The protocol that runs over the connector is called controller area network (
CAN bus). There are different modules connected to the CAN bus. Transmission control module (TCM), body control module (BCM), engine control module (ECM), lots more. Many OBD "code readers" are pretty basic and can only communicate with the ECM. For example, if you have a problem with your transmission, your basic code reader will show P0700, which just means that the TCM requested that the malfunction indicator light (MIL, aka Check Engine light) be turned on. To determine the true cause of the issue, you need a code reader that can talk directly to the TCM and ask it for
DTCs.
Sometimes there are advanced CAN bus protocols. GM has "
HS GMLAN" (high speed CAN bus) and "
LS GMLAN" (low speed CAN bus). Other manufacturers sometimes have other CAN buses that are specific to their brands. Sometimes they just run multiple CAN buses for different things. For example, Volkswagon has an infotainment CAN bus.
There is a protocol on newer GMs called
Diagnostic-over-IP (DoIP) that is an ethernet network (versus CAN) running Internet Protocol at
OSI layer
3, and my understanding is that new features like
Super Cruise use DoIP. So it's possible that only a MDI2 would work for communicating over that protocol on GM vehicles. I think there is a CAN bus command that the MDI2 uses to connect to a CAN-to-DoIP gateway, and after connected, the MDI2 can communicate with devices connected to that ethernet network by using ethernet packets.
For many manufacturers, they use Bosch diagnostic software and customize it. General Motors calls their software GDS2. They also have a program called SPS2 that is used to update firmware.
The device that connects your computer to the car's DLC port is known as a J2534 device. Some people call them J boxes.
General Motors uses a J2534 device called a MDI2. You can
buy one yourself if you have $800 laying around.
There are MDI2 clones from China that used to work, but the latest versions of GDS2 have blocked them. I think the clones are technically J2534 devices though. This guy on
Youtube upgrades software on cars on the side for extra money. He uses a MDI2 clone with no problem (also has info on programming other manufacturers). He also demos GDS2 and SPS2, so you can see what the software user interface looks like.
Ford uses a J2534 device called a Rotunda VCM3. You can
buy one for a mere $1800
Bosch makes a J2534 device called the
MasterTech II. It's $2076.
Notice that the VCM3, MDI2, and MasterTech II all look similar. I have the MDI2, and I've been able to verify that it was made by Bosch. I'll bet the VCM3 is also made by Bosch.
Honda uses a J2534 device called a Honda Antares Capsule (HAC) . You can
buy one for $779.
There is a company called DrewTechnologies that makes a device called a
Cardaq 3. Supposedly, that one is made to work with all manufacturers and DrewTech makes a program called
J2534 Toolbox which can be used with all cars that support J2534.
Back to software... most major manufacturers will allow you to lease their diagnostic software for a period of time. It isn't cheap.
GM GDS2 is $64 for 3 days, $254 for a month, $644 for a year
Ford FDRS (
Ford Diagnostic & Repair System) is $150 for two days, $300 for a month, $900 for a year.
Snapon maintains a list of diagnostic software used by all manufacturers and links to buy a license at
Ineos Grenadier isn't on the list (yet).
Ok, what does that have to do with Grenadier? Well, I'll bet if you could source Grade-X or the official Genadier diagnostic software, that most J2534 devices would work with those programs. There is a guy on
YouTube who is using the MasterTech II with Ford's FDRS, so I think these things are mostly interchangeable between manufacturers.
Another thing that is cool on Ford vehicles. Someone wrote a program called
Forscan that can change just about anything on the car. Want to permanently disable autostart? It can do that. It can also read diagnostic trouble codes (DTCs) from
some modules.
Now that I've provided the basics, hopefully someone else will go dig and figure out if any of this stuff works with a Grenadier. DrewTech's
J2534 Toolbox is one to try. If you can get the Bosch branded Grade-X, maybe it can get some info out of the car. Once this is confirmed, maybe someone will be inspired to write a program like Forscan for the Grenadier.