ALDL Code Reading/ECM monitoring

[NeonHomer]

I have been reading about different harnesses that you can build that will let you hook to a GM ALDL connector to monitor the ECM. Has anyone tried using any of these on a 88 Cutlass Supreme?? If so, which one do you use?

 

I've also seen a couple of harnesses you could buy. Does anyone know about `em?

[TGPilot]

I am not sure the specific application for what you want to use it on, but there are a few links on this webpage for ALDL cable to laptop... 8)

 

http://mwbackus.home.attbi.com/main.htm

[GnatGoSplat]

I have a Diacom cable and it works perfectly on an '88-90.

Won't work on my '94 though.

[89Cutlass]

Hey what all can you monitor ?

[Redfox340]

GnatGoSplat,

 

That's very interesting; your 1994 won't work? Running an OBDII? Would like to hear more on this project... would like to do this for my 1992 if possible.

 

- RedFox340

[NeonHomer]

Just out of curiousity, is there any gain from going to a later year PCM/EPROM? I found a few schematics on the net that shows me how to build a harness, so I am going to take a crack at it (I should be able to build one, I am an electronics technician!!)

[GnatGoSplat]

GnatGoSplat,

 

That's very interesting; your 1994 won't work? Running an OBDII? Would like to hear more on this project... would like to do this for my 1992 if possible.

 

- RedFox340

 

The 94 is strange, it's an updated PCM that supports SFI and MAF, but is still the same black metal box as 88-93. I'm thinking it's a similar datastream, just that my version of Diacom is too old to support it.

 

On the 88-90's it shows everything. Stored codes, VSS, Knock Retard, Commanded AFR, RPM, %EGR, %TPS, spark advance, sensor voltages, etc. Too much to type. It also logs and graphs. I'll have to get a screen capture.