Results 1 to 2 of 2

Thread: E38 PCM L92 SWAP Odd problem ------------ Runs but no powertrain relay control-------

  1. #1
    Potential Tuner
    Join Date
    Oct 2013
    Posts
    2

    E38 PCM L92 SWAP Odd problem ------------ Runs but no powertrain relay control-------

    Long story short Im finishing a l92 swap and got the car fired and running but not able to use the powertrain relay output to work. I tried different relays even an oem gm powertrain relay but no go.. I have to feed the powertrain relay myself to power up the coils and stuff.. also no fuel pump control either... i get a ground blipping on my probe when i crank the engine (it starts blipping and stops when i hit the key to crank)but not a constant signal to power a relay seems like a pwm signal to way it pulses but not strength ... i dont have a scope to look at the wave signal.. but other wise the car fires right up and runs..
    I haven't been able to drive it yet as im finishing up the wiring and misc stuff... also I have attached a relay and resisters to the starter control wire (yellow/black) but still no luck.. i have enabled diagnostic and disabled it to the starter relay but still no signal at the powertrain output wire... now i can just wire it to a switched power but dont want to risk burning up the coils by accidentally leaving the ign powered on for to long.. anybody know of a relay that can sense minimal rpm to act like pcm and switch it off if it sees no rpm but key on power? also can it be when a removed to vats i removed 1 and 2 at the same time maybe it didn't need both removed and that is causing the computer not to use those outputs(powertrain and fuel pump)?

    Any help would be appreciated,
    Marvin

  2. #2
    Potential Tuner
    Join Date
    Oct 2013
    Posts
    2
    Is there a way to set the pwm on the fuel pump control wire (green/white) to 100% so that i get a constant ground to the output? I know on the e67 ecm its possible.. I worked on a dual pump setup on a 09 cts v and when we removed the factory fuel pump control module the green/white wire has constant ground when active..on that setup it controls two bosch relays 30amp's each.. I dont remember were it was set on the ctv s but i know it have a constant ground when active not pulsing like a pwm setup..