Ecm won't link to scanner!!
I have a 1998 Chevy Express van 2500 with a 305. The van will turn over but will not start there is no spark or fuel delivery. I plugged my Mac Tools hand held scanner into and will not link to the ECM it says link error. I thought I was the ECM so I put in another one and still having the same problem, anyone have any ideas what might be going on I would really appreciate it this is my work van. The ECM number is 16250279.
You need to see if there is power in the data link connector. For dumb some reason the data link connector shares the same fuse as the lighters. Also you can not just swap a new OBD II computer in the any vehicle because it must be programmed or it will not run but it should still communicate. I think a used one MAY only work if it was from the exact same year. Did you try your scanner on another vehicle maybe the problem is with it.
There is power to to scanner when I plug it into the port it just does not communicate with ECM. As far as I am aware the computer is from the same year, I am not 100% sure because some of the markings on it are gone but the numbers I have match up.
There is no chips to change in this computer, there is power going to OBD plug so no blown fuses and the reason for replacing the computer is the same thing, van would not run, no communication from OBD port assumed it was a computer issue as the van has no fuel or spark. Now I am wondering if something has gone wrong with the security switch in the ignition not allowing the van to run, but that does not explain the no communication problem.
Just because your DLC has power, doesn't mean the ECM has power. they are not on the same power circuits at all.
check your fuses
check your fuses
I have checked every fuse in the truck, there are no blown fuses so I am assuming there is power to the ECM. The old computer was completely covered in corrosion and actually split open because of it. All of the plugs were completely covered as well I cleaned the all before I switched the computer. I am wondering now if the problem is somewhere in one of the plugs.