Where is the OBD2 port on an MG5 ?

[Rob Smart]

Has anyone discovered where the OBD2 port is on the MG5, and are there any apps that can link to it that might reveal some interesting information like Battery State of Health?

 

[greentangerine]

There's a mention of it over on the OVMS pages but not the exact location. Someone has successfully been getting data out though.

I'll take a look tomorrow when it isn't dark and raining.

 

[Jocko]

With a shift in rules, electric cars are no longer required to have an onboard diagnostic. You’ll find that recent models of fully electric vehicles have no diagnostic port.

Common Diagnostic Ports For Electric Vehicles - enrg.io

The coming decades will continue to witness a revolution in motor vehicles, with electric cars set to outnumber the traditional cars that use an internal...

enrg.io

 

[jonathanhoey]

It's under the steering wheel, offset slightly to the left. The port faces vertically downwards (ie you push the dongle straight upwards on to it).

 

[jonathanhoey]

You should just be able to see the bottom of the blue dongle above my left shoe. You have to reach up and under the lower bit of trim to get to it.

It’s not super useful so far. The only reading I could get out of it was the state of the accessory battery, and you get that for free on the dashboard anyway.

Was hoping for things like motor speed, vehicle (GPS) speed, possibly coolant temperature, HV battery state... it may be possible to get those things but not using the app I tried (Incardoc Pro for Android).

 

[jonathanhoey]

Had another go with a different app (Torque) and essentially the same result. Torque did show me vehicle speed but I think it was just reading it from the phone’s GPS, not from the vehicle.

A lot of the fields do appear to return a value, but it is stuck at the maximum possible for the range. So for example, the rpm is showing as a constant 16,384, the speed is showing as a constant 255, and so on.

 

[greentangerine]

Most OBD2 apps have a car profile you need to select in order to get the correct / supported values. I suspect most, if not all, don't support the MG5.

 

[jonathanhoey]

That could be something to do with it, certainly.

I’ve always rather suspected that those profiles have less to do with the actual values (which are basically just a load of raw numbers within a predefined range, and in theory should be the same from vehicle to vehicle in order to conform to the ODB2 protocol) and more to do with how to display them (eg omitting ones that aren’t relevant to the given vehicle, etc).

I’m in no way an expert on any of this (more of a barely-informed layman with half a clue at best) so will graciously defer to anyone with more actual knowledge than mine

 

[Fluffykins]

Here's a bit of info on the Torque profiles. Theres probably a good deal of reading available for this app and other similar apps, which you can use as background info.

Vehicle profile - Torque OBD2 Wiki

 

[Jocko]

The thing is, there is no OBD2 protocol for EV's, as there is no need to fit an OBD2 port.
The "OBD2" port on the MG5 may be a port that the MG dealer can interrogate with a dedicated device/software.

 

[ALANB]

Manged to get SOH and SOC and 12V battery voltage with Car Scanner, but as others have said some really weird readings for things like speed.

 

[LiamWhales]

I put together some torque PID's for getting live data in abrp.

• State of Health
• State of Change
• HV Battery Voltage
• HV Battery Amps
• HV Battery Coolant Temp
• Maximum Charge Rate

You can get them here Here

 

[Petriix]

I'd be interested if anyone manages to pull the min and max cell voltages. That's a fairly crucial piece of information.

 

[LiamWhales]

Here is the work that's been done for the ZS by the guys for OVMS over at

MG Discourse

Discussion group for user modifications, custom features, and OVMS development on the MG (SAIC) EVs.

discourse.mymgzsev.com

When I was looking through the PID's I was only focusing on the ones needed for tracking efficiency but it looks like they have the Max/Min Cell voltages on PID's 22B058 (max) and 22B059 (min). The BMS seems to be the same between the ZS and MG5 so they should work to return the data. When I get some time I'm going to go through the lot and get all the info together into a torque profile.

Torque does seem to struggle a bit with getting the data from the Car often returning blank values. So I've had to do some maths trickery to get it to ignore the blank values when they come through.

 

[LiamWhales]

So I have put together some additional PID's from the work done for OVMS. I haven't fully checked the figures coming out yet, some do seem off but we can now get in addition to what I shared before,

• Battery Bus Voltage
• Battery Resistance (I think this is out, so wouldn't trust the scale of this figure)
• Cell Max Voltage
• Cell Min Voltage
• Battery Cell Temperature Highest
• Battery Cell Temperature Lowest
• DCDC Input Amps
• DCDC Input Volts
• DCDC Output Amps
• DCDC Output Volts
• DCDC Amps
• DCDC Load
• Inverter Temperature
• Motor Coolant Temperature
• Motor Speed (rpm)
• Motor Temperature
• Motor Torque