Code Reader for all GM Modules

[800DiagTech]

I have a shop scan tool that reads DTCs from all my GM modules, but (annoyingly) does not fetch history DTCs. But since I have a OBDLink LX+ - which supports J1850 GM Class II Serial VPW - I wrote an android app to fetch the current and historical DTCs from all my modules.


Which makes me wonder: is there already an app that can read current and historical DTCs from all of the modules on J1850 GM Class II Serial VPW network?

 

[azswiss]

An app is not necessary. You can directly query the network using an ELM327 adapter and a serial terminal app like Kai Morich Serial Terminal.

Below is the command sequence I use to get MIL, Current & Pending DTC's for all modules on my '03 Suburban:
ATZ
ATSPA2
ATH1
ATS1
ATAL
ATSH6CFEF1
1980FF00
1902FF0
1940FF0

The output will be in HEX but is easily converted. The attached Excel spreadsheet translates the HEX into text (note: depending on the vehicle you may need to edit the module addresses).

 

[800DiagTech]

Yeah using AT commands for ELM327 and Kai's terminal app is great, and I have used it a bunch for network sniffing.

My goal is purely convenience. I'm looking strictly for an automated Android app that does the heavy lifting instantly on a phone. If a polished app that reads GM history codes across all modules doesn't already exist, I'll just finish building my own.

 

[azswiss]

Got it, makes sense. Not being a coder I had to be satisfied with setting up a macro in the terminal app to execute that string sequence. Even though the output is HEX as long as I see 00 in both DTC bytes 1 & 2 I know I am OK.

Would definitely be interested in the turnkey app once you get it rolling.