OBDX Pro VX - which app?

[TJBaker57]

My first reply/post here!

Thank you Antus for opening the magic door

Others here more knowledgeable on the details can likely explain the following but I will simply say what you need to do to get that PID 1141 to work in Car Scanner ELM OBD.

In short, append "01" to the PID. So replace "221141" with "22114101". You will find that you need to do this with many/most PIDs, at least for older GM vehicles using the Class 2 J1850 serial data protocol.

Torque Pro will do this for you in the background where you don't see it happening. Torque Pro actually tries a bunch of stuff when a PID doesn't work straight away.
I have seen Torque Pro mix and match custom headers from other custom PIDs just trying to get some response! I remember seeing Torque Pro use the header from a PCM PID (6C10F1) and a PID (4101) for my TrailBlazers Liftgate Module!!


Looking at your screenshot showing the response from the ELM "6CF1107F22114112BC" after the 3 byte header you see "7F". That is a general response code, usually means an error. After the 7F you see the mode&PID just like you sent, "221141". After that is "12". That is a code detailing what the error is. I think 12 means the format of your request is incorrect? At least that's what I remember. At the end is "BC", that is the checksum of the message.


I really like Car Scanner ELM OBD for it simplicity in recording and graphing PID data. It has become my primary app for this sort of use

Torque Pro has more functionality its equation editor but is cumbersome for logging data.

I also have OBD Fusion, DashComand, Car Diagnostic Pro, Car Gage Pro and maybe some others.

[TJBaker57]

[turbo_bu]

Thank you for your help. Adding the 01 to the PID helped. I also left spaces between the commands which it didn't like. Time to see if I can make it work on a newer ECM.

[TJBaker57]

Depending on what PCM the definition may be different.

I have a 2005 5.3 LM7 which I believe is a P59??
That supports PID 1141 in the same setup as above.

I have a 2008 P12 PCM which also supports PID 1141 but the setup is different being CANBUS ISO 15765-4. No need for the added "01" and the header field is 7E0.

Additionally this P12 supports mode $01, PID $42. Car Scanner will call this Control Module Voltage. That definition has greater resolution and if setup as a Custom PID might look like this.