Scanmaster install.

[Red87GN]

I recently bought a basket case 87 GN. God have mercy on the wiring in this thing. Most of the wiring is hanging close to the floor. Amazingly enough it does crank and run though. The car has a different motor in it from original.
It seems that the ALDL connector is missing in action. The instructions say to plug into pin E on the ALDL, what is the actual ECM pin designation so I can pick up the signal there.

Who makes a good wiring schematic/service manual for 87 Turbo Buicks?
Thanks for the great web site. Where would we be without it?
John

 

[kenmosher]

Helm prints the complete chassis manuals. Excellent stuff!

Also, http://www.gnttype.org (specifically http://www.gnttype.org/techarea/electrical/wiring.html) can probably get you close.

 

[Red87GN]

Scanmaster wiring.

Thanks Ken, I'll try to find that book, today I ordered a Haynes book from DAP for $15, hopefully it will have something in it. I tried looking at that scematic at GNT-Type. org and couldn't read most of the stuff on that diagragm. Thanks again.
John

 

[ponch]

Maybe this will help

Click here

 

[Red87GN]

ALDL pin E?

Ken,
Do you know which pin on the ECM is the same as the Pin E(orange wire) on the ALDL connector, I can't find the wire anywhere under the dash.

Also do you know exactly which book Helm makes for the 86-87 Turbo Regals? Maybe the ISDN# or the exact title?
Thanks
John

 

[kenmosher]

http://www.gnttype.org/techarea/ecmsensors/ecmpins.html


Looks like A9 (white/black).

As far as the Helms manual, they sell a complete set of Buick chassis manuals (about 50lbs of paper!) for the model year you request. It covers all models and is similar to the manuals the techs used "back in the day"

 

[Red87GN]

Scanmaster blues!

Ken,

According to The install instructions, it says the white wire connects to pin e(orange wire) which is the serial data line from the ECM. That link you posted above shows the complete pinout and shows A8 as the serial data pin. A9 shows to be the diagnostic term to aldl.

Anyway I hooked my white wire up to A8 and the scanmaster flashed the ver. # then goes right back off, the instructions say that this will happen if there is no data stream present. But there should be does the data go through some other device before going to ALDL(which I don't have) connector. Thanks
John

 

[Red87GN]

ECM pin A8

Ok Guys this is really bugging me. I have connected the white wire from my scanmaster to the orange wire going into A8 at the ECM. And I'm still not getting any data stream to my scanmaster. I'm beginning to wonder if I may have a bad ECM, but the car would run until last night(although it had a bad miss) Now it won't start at all and worse it backfired real bad last night. I really would like to get this scanmaster working so I can see the codes that come up so I'll know where to start.
John

 

[salvageV6]

A8 Orange wire is the correct data wire.

 

[tim87tr]

good info in this link

Try this link out for some good info:
SM Hookup Details

 

[Red87GN]

Not getting serial data!!!!

Ok I have the thing hooked up, it's just telling me that I'm not receiving anything from A8, what I'm asking is whether or not the wire from the ECM goes somewhere before going to ALDL(like maybe through a buffer or amplifier) if not then I have a problem, I would guess my ECM is bad.

The scanmaster powers up and shows the rev# 2.1 and the right decimal point flashes but afterabout 2 seconds it powers down and the instructions indicate that if this happens there is no data present. What do you guys think?
John

 

[kenmosher]

Nope, nothing between A8 (sorry about "A9" .. I didn't spend the time to look at it closer) and the ALDL.

The test bench ECM I have here is wired directly to that wire and ground for the ALDL.

Sounds like maybe the quad driver in the ECM might be bad (which controls the serial data line, among other things).

 

[salvageV6]

I'd take the wire from the Scanmaster and run it right to the ECM itself to make the connection.

Maybe there's a break in the line over to the ALDL port.

Worth a last ditch shot before swapping the ECM out.

 

[Red87GN]

A8 Serial data line.

I am wired directly into A8 about 3 or 4 inches from the ECM, one thing to note when I got the car, both connectors were slightly corroded as was the pins on the ECM, I used some contact cleaner and an old toothbush and cleaned both, how do the pins themselves come out? Are they like a Ford ECM? on them you remove a plastic clip that keeps the pins straight and then use a jewelers screwdriver to pry a small keeper away then pull it out, the Buick anything like that?

Also the car came with an extra ECM that was supposedly bad, something witht he PROM? Should I try it? Is the chip hard to change out(it's a stocker)?
John

 

[Red87GN]

Scanmaster ?????

Ok guys I have a good ECM(from Red Regal T) and a good harness that I bought from a guy that was parting out a car. Where is the best place to start when replacing the entire main harness of a GN. I have all the wiring under the dash and underr the hood.

 

[Red87GN]

Done with wiring.

Ok now that I'm done putting my new wiring harnesss in I put my Scanmaster back in. When I first applied power to the car I used a battery charger to check out everything. When I first put power to it the scanmaster come on, flashed the version and then went out. After several times doing this I went ahead and hooked up the battery to see if the additional voltage would help. When I powered it up this time the decimal point flashed and kept flashing this time and then displayed the dashes like the manual said it would do when it was waiting to be cranked up. I have noticed that sometimes it acts like it isn't receiving serial data when I know it should be. If I turn the key off and on several times it will go into the right sequence. If it has any codes should they start flashing right away or will it have to be cranked first? John

 

[Red87GN]

Anyone?

Anyone?

 

[Red87GN]

Problem solved.

ECM was bad. I finally got the the scanmaster to stay powered up. It appears that it is real sensitive to having at least 12v and above. I was turning the key on to try and see what codes popped up. It would come on anbd then shut off after a while. I hooked up the charger and had a steady 13.4 volts and the it finally registered code 55 and 43. Not sure what exactly 55 means, but it says bad ECM. Well I had one more ecm and it turned out it was good. 43 is because of the missing ESC module, I have one on the way from Red Regal T.

Things are definitely looking up, right now. The last hurdle I have to get across, is how my trans is going to shift. I have an automatic valve body Turbo 400 and I'm not sure what to do to make it shift under boost. Thanks again for all the help thusfar.
John