pcm help
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Joined: Oct 2014
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pcm help I rebuilt motor installed somehow the alternator batt wire got mixed up and bolted to grounds on frame by abs installed batt cable sparks so i took it off . My main problem is now thats (fixed all grounds have been checked relays all in working order ) i get no fuel pump prime at fuel relay get my constant 12v then key in run get 12v but no 2-3 sec 12v for prime other issue starter will not turn over im getting no voltage to purple wire have 12v out of big red wire at batt couldim leaning towards a fried pcm due to the 12v alt wire to ground but not sure as i know vats is working ohmed key and checked plug under column both match just need help im new to ls game car iss 99 z/28 also speedo is pegged out all interior dash lights work horn blinkers
im confusedget
no fuel pump prime at fuel relay get my constant 12v then key in run get 12v but no 2-3 sec 12v for prime
"then key i run get 12v" where is that 12 v measured at? The fuel pump relay?
Can you jump the fp relay and turn the pump on?
I dont think you have enough to determine its the pcm yet, but its an easy swap to test.
I would swap the pcm, cause I have some around. But I m not convinced that it isnt wiring /fuse related yet.
Can you scan the pcm with the key on? It sounds like the pcm ist getting power.
no fuel pump prime at fuel relay get my constant 12v then key in run get 12v but no 2-3 sec 12v for prime
"then key i run get 12v" where is that 12 v measured at? The fuel pump relay?
Can you jump the fp relay and turn the pump on?
I dont think you have enough to determine its the pcm yet, but its an easy swap to test.
I would swap the pcm, cause I have some around. But I m not convinced that it isnt wiring /fuse related yet.
Can you scan the pcm with the key on? It sounds like the pcm ist getting power.
Thread Starter
Registered User
Joined: Oct 2014
Posts: 13
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All fuses and relays are good when i meter out the fp relay i get a 12v constant then when i turn key to run i still have 12v constant but i also have another 12v on second probe but no signal of 12v for 2 or 3 sec to prime but i tried jumping pump and nothing but i should still see the 2 to 3 sec prime then ill change pump im really conserned with the no cranking issue how would i check and what would i check to see if pcm is getting powered. Also i grounded the black/yellow wire bcm with no change
