Ok I have an interesting question. I have an EF XR8 motor and 4 speed auto in a 67 Muz.

When I picked up the motor I had the computers but no wiring loom for the TCM. I grabbed a set of the yellow plugs for the TCM out of another falcon. Everything has been going great except that it seems to find limp home mode after it gets to operating temps.

When I first start it it now changes gears fine, until it gets warm. I had to put in the jaycar correct to change the VSS signal from AC to pull up (2 pin VRS USA VSS installed instead of the original 3 pin hall efect one)

I'm also getting a 637 error on the KOEO test. (Trans temp stuck high)

What I need confirmation with is...
Does the ECU ignore trans temp while cold? From what I understand pin 34 on the ECU receives a trans temp signal in a frequency 10Hz to 40Hz depending on temp. 12v if it is in limp home or 0v if it is rooted. I have pins 1 & 5 connected on the TCM however the yellow plugs I picked up doesn't have a pin 3 so it isn't connected to pin 34 on the ECU

Would not having this wire connected cause the 637 code? and would not having this wire connected cause the ECU or TCM to put everything into limp home mode? Excuse any ignorance shown but I haven't really gone into this side of the wiring because I have only got the thing mobile

(It isn't registered so I left the driveshaft shortening till last so I wouldn't drive it around)