computers causing different cranking

[rappa]

I'm trying to get my vt started, have spark and fuel but not firing, what I've done now is change the ecu computer. The original was allowing continual cranking, now when changed to this new unit I only get motor cranking maybe 2 turns then stops, why would they be cranking different when all I've done is switch between the two?

[camstatic]

Sure the battery isn't going flat progressively?

[lout]

the new ecu is immobilizing because you haven't linked it to the bcm

[ephect]

plug ur original ecu, then check your error codes, as lout said, its sounds like the immobiliser isnt being switched off on ur old ecu.

[Doctor Bob]

the PCM needs to be linked to the BCM or you will never get it going.

Rob

[rappa]

how do you link pcm to bcm, does one need reprogramming?

[rappa]

checked for error codes and found none,,

[Doctor Bob]

the linking needs to be done using a Tech2
why are you changing the PCM anyway?

Rob

[rappa]

I'm changing the Ecu (computer) because I've got spark, fuel and cranking and compression but not firing, have swapped dfi module, coils, crank angle sensor, checked fuses, searched for bad connection, been all over things and now figure try ecu. Got it from wreckers and was told to simply plug it in and turn key!!@ Dada only cranks two turns and stops. Been in and out of holden dealers and they're no help, trying to fix problem myself by elimination...I've swapped original memcal into this new ecu and not made any difference.