Hey guys, I've been searching around and reading on how to read mode 23 addresses using an elm327 enabled Bluetooth device. I can't seem to find any information on it. Everytime I request mode 23 addresses I get 7F responses. Question is, what do i need to do to read mode 23 addresses? Do I need to initialize or use a specific header? Here's some of the output of stuff i tried. Thanks for your help in advance.

>AT SP 6
OK
>AT H1
OK
>AT SH 7E0
OK
>23808746
7E8 03 7F 23 12
>AT SH 7DF
OK
> 23808746
7E9 03 7F 23 80
>AT SH 7E8
OK
>23808746
NO DATA

 

1.- It need to be enable in your ROM obviously first.

2.- you need to start a "StartDiagnosticSession" before asking for data per specification.

 

Thanks for the reply, mode 23 is enabled in my ROM. And I figured I needed to do something like "StartDiagnosticSession" as you said (thats why i asked in the first post do I need to initialize), but how would I do that? That's basically what I need to know. Thanks again.

 

Start Diagnostic Session:

service id 0x10
extended diagnostic session: 0x92

so something like:

07 E0 10 92

that what I have in my code.

Mart

 

Thanks for your help Mart, I'll try that tonight and report back. I appreciate it.

 

It isn't working for me, here's the output:

>AT SH 7E0
OK

>10 92
7E8 02 50 92

>23808746
7E8 03 7F 23 12

Any idea what's going on? Thanks.

 

I do have some handy log of what I do in my firmware/hardware but here is some can log from a cobb AP session:

0x10 = start diagnostic session

[661612654] 00 00 07 DF 02 10 92 45 F8 F8 F8 F8
[661634217] 00 00 07 DF 02 10 92 E3 38 38 38 38

0x3E = tester present

[661653376] 00 00 07 DF 02 3E 02 90 38 38 38 38
[661654433] 00 00 07 DF 02 3E 02 02 38 38 38 38

Mode 0x23 Address 0x809505
CAN_0x23_X_OS_VER22_ACCEL_PEDAL_POS_PERCENT

[662225530] 00 00 07 E0 06 23 01 80 95 05 02 21
[662227101] 00 00 07 E8 03 63 01 33 00 00 00 00


I dont do the tester present query...

Mart

 

I think I got it, the problem was I needed to send the address like so: 23 01 80 87 46. Now I'm getting 63 responses. Thanks for your help.

 

Also, I didn't have to start diagnostic session, it just worked.