I’m trying to get data from an old (1996) Chevrolet Suburban 6.5TD, and after a bit of a hiccup, it started to work. However, I’m having trouble decoding the GM-specific mode 22h data. For example, I found CSVs online that describe the fuel rate measurement as mode 22h, PID 1222h, with the fuel rate being A*0.3125 mm3.
With this goal in mind, I tried sending this command through the console:
obd.send 221222 expect_response=True
This produced the output values:
- 48 6B 10 7F 22 12 22 12 45
I’m not quite sure how to decode that, but to me the 7Fh seems like the error response described on the OBD-II PIDs Wikipedia page, and the result data doesn’t change with different throttle inputs so it quite obviously isn’t correct.
Should I use some other header except the default 7DFh? If so, how would I determine which one to use?