hey guys i have noticed something with my car i have had engine light on for several months due to one problem but i decided to check and see if there any other codes in the computer but when i hook up the code reader it doesn't get any signals or "power" from the plug under the dash i have tried it with several code readers and none work with my plug. so i am woundering if there is a fuse or bad wiring or something i just need to get it working again thankx hope u guys can help me solve this problem

check the cig lighter fuse

ok so is that where the plug gets its power from cuz i have been wiring things up to cig lighter so i could have un hooked it or something could u find out what color the wire is??

its not a matter of the DLC getting power FROM the cig lighter, but they are both probably powered from the same fuse, so if you were messing with the wiring of the lighter then you could have accidently grounded it out at some point, or overloaded the circuit and blew the fuse. the DLC supplies power for any scan tool unless it's got batteries in it, so if the DLC doesnt get power, no power for the scan tool

sorry about this but my cig fuse is good and has not blown so where do i start toubleshooting this prob cause i really need to get it working again by the way its a 99 4dr cavalier 2.2l

ok i checked out your DLC schematics and it's actually getting power from the horn fuse. should be a 15 amp. if that is still good then you've probably got a broken wire to the DLC. what you wanna do is get an electrical meter (use a multimeter, not a test light cause you wanna make sure it's more than 9 volts or so). go to pin 16 on your DLC. rather than try to describe which pin is 16, just look on the back of the DLC and find the orange wire that's on the end. that's pin 16, your voltage supply. check for voltage there. if that's ok, check your grounds to the DLC, that would be pins 4 and 5. they are next to each other, ones black, the other is black with a white stripe. if you are missing power or ground that will cause the scan tool to not power up.

if you have power and ground and still cant talk to the ECM then i can look up the schematic for that and walk you through it.

ok thanks everyone for helping me out i figured out the problem and happens to be that the horn
fuse blew and i didn't know it but thats where the power comes from