How difficult will it be to decode the data stream for the 1227748 87 & 88 2.5 Fiero?

[phonedawgz]

Just wondering. Any hints on where to start with this?

[EagleMark]

Do you know what the engine RPO code is? If so it's easy, just look up the origanal ALDL.ds data stream file and build an ADX file for TunerPro, if there is not one already.

[EagleMark]

So I think that is an LR8 engine, the ALDL list says A027 and here's your ADX

[phonedawgz]

So with TunerPro, I do get a connect, however all I get is 'dancing numbers'.

hmm

2.5 Tech4 aka Iron Duke

RPO = not sure. I believe LR8.

The VIN digit is for sure an R however.

[EagleMark]

Did you add the extra byte to reply for TP V5? I judt did, give it a shot.

There is a note in there to use 10K resistence, wheather to start or to get or correct I don't know. I have seen that note in some old ones that is not correct.

[phonedawgz]

The data stream doesn't start without the 10K resistor, so yes I have it in.

It's not like the extra timing needed for the V5. Its like every frame of data is messed up. So all the numbers dance about 9 times a second.

[EagleMark]

I've never worked on that ECM so not sure other then try the extra byte and or a pause? Also 10K to start then remove it? Try without it because the ALDL file does not say it is needed?

[phonedawgz]

As soon as the 10K is pulled the data stream just stops.

The trouble seems like it is like the raw data numbers are not being synced correctly. Maybe like the data stream is not finding the proper header to sync the data.

A majority of the data numbers are zeros, but then some are high value numbers. And it ticks with new numbers about 9 times a second.

[EagleMark]

I can't find any notes that there are other modules needing to be silenced on this, do you know if the car has any other modules?

There is also some notes that data is from pin M which would work with all cables I know of, but there is a possibility, because it's mentioned pin L which would not work with any cable I know of...

[phonedawgz]

The data is on pin M of the 12 pin ALDL connector. No there are no other electronics operating on this vehicle.

How does TunerPro decide what the header is for the information block?

[EagleMark]

I just looked at this ADX and the ALDL file and... I have no idea? The ALDL file does not have any?

 
                        DATA STREAM A27   SPECIFICATION
   ENGINE USAGE:
             2.0L OHC TBI - (LT2) - (K) - 87
             2.5L TBI     - (LR8) - (R) - 87,88
             2.5L TBI     - (L68) - (U) - 87,88
   DATA PIN: READ DATA ON PIN "L"/"M" OF ALDL CONNECTOR
   MODES:       OPEN    22 BYTES
                10K     63 BYTES
                SHORTED 22 BYTES
   BAUD RATE: 8192
              The LT2, LR8 and L68 engines are a GMP4 MID - FUNCTION ECM.
..HEAD02L ALDL DATA LIST 
..HEAD03L NUMBER OF DATA WORDS - 63
..HEAD04L ALDL MODE 1 10K MODE 
..HEAD05L WORD  BIT   LOCATION
..page

Robert Saar! Where are you?

[RobertISaar]

blah. 1227748 = oddball ECM, kind of like the 1227165. apparently it's a P4, but it also uses a small PROM? like a 2732, not the normal 27C128/256/512....

not quite certain how to recognize the start of a frame since apparently nothing is sent to the ECM to start the stream, just the 10K, which is different than the 7165.

[EagleMark]

The A027.ads file has your name as author, but it has Transmit send of "0xF0 0x56 0x01 0xB9 " which is not shown in ALDL.ds file. Actually it's the first I've ever seen with nothing? Everything points to A027 being correct for this car.

Wonder if it should be nothing? Let the 10K send data like a 160 baud? Weird, wish I had one here to figure out...

[RobertISaar]

now you see my dilemma.

the transmit command, i basically pulled out of nowhere, since an 8192 baud application without a command makes no sense to me.

[EagleMark]

0xF0 when did FO poll start? Poll what on that car? Have you ever looked at the $6E that has commands in 160 and 8192? Wonder if that comes into play here? Hyper Terminal? Great now I'll never sleep tonight...

Once when I was bored I read the ALDL.ds files in order and some have information that carries through to others. But this one I read back and can't find nothing.

phonedawgz did you ever look into a Fiero forum to see if they got TunerPro to work?