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high or low voltage

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1chevy02

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my friend has an 03 lb7 he was triying to install a ppe tuner and the ecm locked down on him. I tried to reflash it and it would just say after initalizing the bootloader that the ecm voltage was to high or low. He took it to the dealer and they told him the ecm was fried. we repalced it and the new one does the same damn thing. btw we have tried new batteries, charger, no charger. we have tried it at every voltage possible from 11.5 to 13.8 and NOTHING makes a diffrence we have checked every fuse wire and added on accessory we can think of please HELP
 
idk how would you check that shurely the stealer would have found THAT in all seriousness is there any way to moniter actaul voltage at the ecm with efi btw i can read bothe ecms just fine and the files are not corrupted but the truck has been down for over a week and he is getting anxious to say the least
 
only a week, thats nothing he doesnt know what anxious is.

i am not aware of a way to test voltage.

i would say if the dealer cant find it take it to a different one.

The computers need only 9 volts, lower than that and they will shut down.
 
Stay away from using a conventional battery charger when programming the truck. The voltage fluctuations caused by a normal battery charger can damage the modules during programming. It also causes interference in the communitcation lines. Here at the shop we have a special battery maintainer (that cost us about $500) that produces "clean" DC voltage. If you need to supliment the battery voltage use a jumper pack or another battery.

Has the new ECM had the initial programing and theft relearn done? You may also want to check your voltage at the DLC.
 
You have to have a tech 2 and access to GM Global Connect to get to SPS programing. I'm not sure if it would prevent you from loading the tuner or not, but it will keep it from starting.
 
the old ecm did the exact same thing i can read it just fine and none of the files seem corrupted on either
 
no the tuner was stuck in the old ecm but since the we have replaced the ecm and i get the same codes
 
yeah they have no idea but theyre reflashing the ppe right now but we havent made any progress once for a little while he said he had voltage but the next day before i got there to reflash it then we had none again so its got to be a wiring problem so were trying to trace it right now
 
not the ignition switch figured out that pin 19 blue conector and pin 44 clear connector are not getting switched voltage like they are supposed to
any suggestions
i really need a better wiring diagram right now to see where they go because all mine says is ign. switched on both pins
 
Ok, sounds like you're on the right track now. When i get some down time tomorrow i'll try to post you up some schematics
 
finally got it running!!!!!!!!!!! he took it to a guy who worked at a local stealership and he worked on it after hours. it ended up being a fried fuse box
wallbash.gif
no idea why it would suddenly do that but hes just happy to have it running now i have an extra licensed ecm to play with
grin.gif
 
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