no sparks on coil on plug, help ...

[inu-yasha]

hi everyone , the problem is ... last month bought a expedition and there is no spark in the coil on plug , i bought like that . but the mechanic change the crank sensor and nothing happen, the thefh light is blinking but I call a technician keys and said it was fine. so she said that maybe it was the ground on the computer or the computer . if anyone knows how to fix this I will be grateful. oh if anyone can send me a diagram to use and check all grounds to the pcm i will APRECIATED. One more thing the DLC conector look fine BUT a can't read the codes wiht a scanner. ANY HELP......

 

[stamp11127]

First thing I would look at are the fuses for that circuit. Next I'd check for power to the pcm, then check the harness to the DLC. Establish communication with your code reader and find out if there are any stored codes.

 

[Stoned06]

How quickly is the theft light blinking? If it's once every 3 seconds, it's OK, but if it's once a second, you probably have a PATS problem. I know you had it checked out, but just want to verify it for you.

 

[inu-yasha]

already check the fuses and all are good, also change the relays and nothing yet, also buy a Haynes manual and check the computer ground and all good. and I want to know which wires go to the D.L.C connector from the computer, because i connect the scanner and all go good until the scanner says, ERROR you can't retrieve any data. but i test positive and negative in the D.L.C and all good , so I don't know what else.

 

[stamp11127]

The pcm is located on the firewall behind the battery on my 99. One of the first checks on electronic problems is whether the connectors are making good contact with each other. I usually disconnect and reconnect them while checking for corrosion or broken wires.

 

[inu-yasha]

thanks for answer..

Already unplug and plug the computer . and everything looks normal. i don't how check the ground from the computer to the chassis. or witch cables are the " ground" if somebody know how check the ground please , let me know how.

 

[inu-yasha]

do you know witch cables are power and ground on the pcm.

 

[stamp11127]

The pcm has more than one wire supplying power to it. You would be ahead in getting the Ford wiring manual and a good test light. That way you save time and money.

 

[inu-yasha]

thanks ... but I guess i will send this truck to the pick a part bcuz i can't found a mechacic o somebody who fix this yunk. sorry and thanks everyone.