Reading data from MHD API

General
1

Is there a way to use this API to reads the data from my ecu?

Stream DME parameters
$ python3 mhd.py --target 192.168.4.1 --monitor
Unknown1 = {‘value’: 61537}
Unknown2 = {‘value’: 65535}
Accel Ped. Pos = {‘value’: 1606.25}
Boost = {‘value’: 22.5}
Boost target = {‘value’: 22.5}
Coolant = {‘value’: 289.0}
Current Map = {‘value’: 256}
Fuel low pressure sensor = {‘value’: 2522.0}
IAT = {‘value’: 289.0}
Lambda bank 1 = {‘value’: 939.8}
Lambda bank 2 = {‘value’: 939.8}
Oil temp = {‘value’: 8806.0}
Rail pressure = {‘value’: 5045.28}
RPM = {‘value’: 65535}
Transmission temp = {‘value’: 419.0}

2

Possible, yes. But I’m not sure if we want to start tackling with MHD licenses. We would need to agree with MHD of usage of their adapters data.

All vehicles supported by MHD support CAN or OBD2, so I would prefer reading data that way.

3

Thank you for that update. The only issue I have so far is that the ECU data runs at a 1 MB rate, and when I try to use that rate, the car does not like it. This would include sensors like IAT boost pressure and such. Any Ideas on reading that data via CAN bus?

4

At least the Seeedstudio, “Type 1” and SLCAN adapter types have been proven to work on 1Mbps CAN bus. Not exactly sure what you mean by “car does not like it”.

Many cars are very sensitive to CAN bus resistance, so when adding a CAN reader, verify that bus resistance is still good.

5

Whenever I try to use the 1 MB data rate, the car screen starts showing issues with the car’s systems, such as traction control, limp mode, and so on. Once I go back to 500k it’s fine. I tried the ohm load as described, and it made no difference.

6

When using 500Kbps, do you see incoming frames in CAN Monitor?

7

At 500 I do I can read the car fine all the data works. When I do 1mb it pulls one line of data the the monitor then stops and the car screen starts with all the errors. When I get my screen working this weekend, I will take a video so its easier to understand what im talking about.

8

Sounds like your car is 500Kbps, not 1Mbps CAN.

9

From what i can tell is that I only get information that provided to the factory gauge cluster. Anything that has to do with ECU i don’t get data for.

10

many vehicles have multiple can bus at different speeds also many modern vehicles have can gateways which prevent the data reaching odb ports too.

for example in the ford world, there are typically 3 can busses and a lin bus. HS-CAN MS-CAN and MM-CAN.

in this setup the instrument cluster and keyless vehicle module connect to the body control module via the MS-CAN, the abs , pcm ecu connect to the body control module via HS-CAN, the body control module forwards pcm messages regarding engine speed from the pcm ecu to the instrument cluster. The instrument cluster also sends the steering wheel button presses over the MM-CAN for the radio to intercept them etc