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Does anyone know how to get information from the ABS module (wheel ticks)? For example, the Autotap scanner offers an enhanced parameter they call "Unfiltered ABS Speed" so it should be possible to ask either the $28-$2F Brake controllers or the more standard $10 engine controller, but which PID must I use?
Thanks!
Does anyone know if any other functional addressing except $6A (legislated diagnostics) work for a GM F-body car?
The J2178 part 4 document lists several 'Primary IDs' that should report data for different modules in the car. For example, I tried to send:
$68 $28 $F1 $02 + CRC
where $28 is the Primary ID (functional address) for Vehicle Speed and $02 is the Secondary ID for 'High Resolution'. I didn´t get a response from the car...
Also, anybody knows what PRN means? It stands for Parameter Reference Number, but is it used in communication or only for reference in the J2178 documents
/Stefan
"5.2 How to Use This Document— This document (SAE J2178-2) provides the definition of parameters which areQuote:
Originally Posted by Stefan
commonly found, or could be expected in vehicle Electrical/Electronic Systems today. [glow=red,2,300]These parameters have
been defined to allow messages on a Class B communication system to have consistent meaning between
manufacturers and over time[/glow]. The parameter definition consists of two parts, the “PRN” and the “SLOT.” The
“PRN” (Parameter Reference Number) is a number used to identify a specific parameter by name, unit of
measure, and its associated “SLOT.” The “SLOT” defines the mathematical characteristics of parameters in
terms of its representation (Binary, Unsigned Numeric, ASCII, BCD, etc.), its scaling (1 Bit = ), its limits and
offsets, and its transfer function."
I'm working on the same problem (Accessing ABS data). I tried to do it via physical address $28, but the ABS module in my Y body doesn't seem to respond to PID requests. I always get a $7F.... $11, indicating mode is not supported.
You are going about it all wrong...
You have to request the PIDS in a packeted format or it will shut you out
We have built an interface that controls and communicates with the ABS/TSR system.
First if your interface package must be able to handle packeted data. Many can't do this and that is why you get the messages you do.
You could try this and see if it works for you then I can send you more... maybe...
Init and csum string removed...
Send 09 6C 29 F1 2A 13 01 02 00 00
Recv 0B 6C F1 29 6A 01 03 03 03 03 00 02
This is the command line for the wheel speeds
LF, RF, LR, RR
03, 03, 03, 03
There are several other strings but that one is very common and I use it almost every other day.
Regards JB