Scanner Issues

[mudbog42]

OK I got a scan tool from autoxray and the cable that comes with it says that it is compatible with all GM vehicles 82-95 OBD1 systems but there are only three out of the five pins that actually touch on my connector and the other two are placed somewhere else and I know there is something wrong because that data it gives is way off. For example my truck is not going 255 MPH or at 6325 RPMs at idle. Has anyone ever dealt with this issue or know if there is a way to maybe jump the connectors to match up

 

[dyeager535]

Shouldn't need but three of the pins anyways. 12V, ground and the data. Cars used the others for things like airbags, etc. All the DATA from the ECM comes off of one pin.

Make sure you've got the right year/VIN plugged into it.

Only issue I've seen with my autoxray is that it never shows RPM while the engine is cranking. Typically bad data is either a bad connection, bad ECM, or wrong settings in the data reader. If you get a code 12 by code retrieval via paperclip, the ECM SHOULD be good, but not guaranteed of course.

 

[mudbog42]

I know my ECM is good because I've replaced it here recently and I do have the right vehicle info entered, 86 GM Vin L and Truck, is what I have it set at but the readings are way off

 

[dyeager535]

If it's the style you can disconnect the plug from the scanner, do so, then plug it back in. A few times if no change. I've had data transmission problems at the ALDL connector as well.

You can also try changing the VIN or year, you might have a couple of VIN options the same year. Shouldn't be the problem, but it could be.

Are those the only two issues, or is ALL the data wrong? (temp, knock counts, etc) If everything is wrong, I'd probably pull the cover off the ECM and check the BCC (3 or 4 letter code on the PROM) to make sure it is the right one for the year/VIN you are using in your scanner. Choosing a different year or VIN may net results though a BCC will narrow it down to the exact year/VIN, given the BCC can be found online.

 

[mudbog42]

Yeah all the data is way off, like coolant temp is -4degrees, battery 25.1 V, mixture control 99.4%, etc. But I'll try disconnecting it and reconnecting it and a different vin. If not could the scanner be bad?

 

[dyeager535]

It could be, got a buddy with a vehicle you can try it on?

 

[mudbog42]

Thats what I was thinking but everyone I know has OBD2

 

[dremu]

I know my ECM is good because I've replaced it here recently and I do have the right vehicle info entered, 86 GM Vin L and Truck, is what I have it set at but the readings are way off

Uh uh uh uh ... 86 is the computer controlled carb, right, and not TBI?

Seems like you'd not get info unless it was TBI.

-- A

 

[mudbog42]

Also if I try to read it with the truck off I get Vehicle not responding

 

[mudbog42]

Ok I Got It

Ok finally its reading. I noticed that the dash light wasn't coming on so I jumped the A & B terminals because I know that they should give like a handshake code when reading codes through the dash lamp and no light was coming on but I could here the truck scanning, so I opened the dash, played with the light a little and on the light came and everything started working how it should. Then plugged and scanner in and got all my readings. So I guess if the warning light isn't working you won't get any data. Sounds wierd to me but thats what happened.

 

[dyeager535]

No, anything with an ALDL connection (CCC included) can be scanned, although 1981 must have been a goofy year.

Glad you got it worked out.