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electronic control module no power

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baddad13

New member
hi everyone. I think i may have a good one. i have a 1997 grand prix gt. no spark excellent fuel pressure.my issue is i was checking the ecm for continuity at the pink wire which there was none. after looking for the problem, i found there is a short at that wire. i connected the clip from my test light to neg. post on battery and found power at the pink wire. just changed out the under hood relay center figuring it was that. still the same. but the strange thing is it has that short even with the ignition off.Im also finding that all the pink wires are doing this. even at the injectors.is there something im missing? has anyone had this problem and found out what it was? ant help would be appreciated. thanks.
 


injector will only flash power when the key is first turned, this primes the engine, then once it cranks over they turn on.
 
the easy way to check the injectors is to unplug one, then take a marker bulb out of your head light, and push the bulb into the injector plug, it will flash if they are working.

being you have no spark, and fuel pressure is good, id think bad icm or bad ground somewhere.
 
i would change the ecm but not having any power and only neg. to it i think i would have to find that out. i traced the wire to #25 fuse and no power but a short. isnt the pink wires power with key on?
 


okay, this was a friends car. i put a fuel pump in it a few months ago. it started to die out than start than finally quit. he thought it was the pump again. i checked the pump pressure and it was fine. i checked for spark, there was none. i figured it was either crank, cam sensors or ecm. he told me to keep the car. so.. i proceded to do the diagnosis. i found no 12 volt power to the pink wire on ecm. now without that it wont power anything else like crank cam sensors. i found that short and traced it to the under hood relay center. i replaced that since it was cheep. hoping to find the old one shorted out inside. still the exact same thing. i did some research and found the pink wires thruot the electronic egnition system get power when the key is on. but every pink wire i test gets negitivity even with the ignition off. this is throwing me for a loop. wiring is not my first go-round. but i may be missing something obvious. I do know that when a circuit gets power with the key on and doesnt. and gets negitive power there has to be a problem.
 
if you have not changed the crank sensor do that, also check its harness over for damage.

the staling and then starting up deal is typical crank sensor symptoms.
 
its getting kinda dark here. but if i disconnect the crank sensor do you think i would get rid of that short? the thing is i disconnected the ecm and had the same issue.
 
when you say ecm you mean the box in the air filter? thats the pcm. "power control module."

unhooking stuff make lots of stuff not work, unplug the crank sensor and it will fail to run for sure. crank sensor and the icm (the part under the coils) work together to send the spark out. the icm also has a ground wire thats bolted to the side of the head. if it broke of the car wont start either.

when the crank sensor goes bad it will do the stall start up deal for quite some time, then it will get bad, like wont fire back up for a hour, or a day, or a week later. they never throw a code either.
 
Electronic control module = powertrain control module.

It just depends on who is saying it and the country the vehicle is from lol. Import people says ECU/ECM.
 


i meant icm, my bad. pink wire at icm.lol. forget about all i said about ecm. change that to icm. i hope that makes sense now.
 
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