91 4EAT to 97 4EAT

[RoughDiamond]

I've heard that the phase 1 4EAT will swap between all the others, but looking at the diagram of the 92 TCU and the 97, the 92 has an idle switch circuit for the TCU while the 97 doesn't.

The 92 says it uses the idle switch to disengage the lock up for the converter. I can't find the operation of the TCU for the 97 in the FSM, but the TPS doesn't have the switch and the TCU doesn't have a pin for it.

Is it still used in the 97? Or does it use a set voltage from the TPS to determine idle?

[bcmaxx]

I dont know the answer but ill find out here soon. In the middle of swapping a 97 auto in my 93

[wtdash]

Hi,
I'd have the matching TCU / TCM ready when doing this swap, but everything I've read leads me to believe the '97 will work 'as is' in the'93.

Assuming you're aware that:
- Rear diff must match the '97 ('95-'99>>ej22=4.11; ej25=4.44) - '92-'94 4EAT are 3.90.
- Rear pinion flange on '95+ rear diffs is different - will NOT bolt to earlier driveline
- Speedo cable will work but must swap the electronic from '97 back to mechanical.
- all i can remember 4now
Td

[86BRATMAN]

Keep all the electronics that are originally in your car where they are. Simply swap the trans and diff. The transmission doesn't care what triggers it to lock/unlock the TC, just that it gets the signal to do so. You are overthinking the situation.