Gasmachine85

I was told if I change the shift solenoids in my 4l60e I will have to reflash my efi, is this true? If so why?


Thanks in advance!

shoebox

I can't think of why you would need to do anything extra when changing solenoids. The only thing you could flash would be the PCM. I don't know what "reflash my efi" means.

Injuneer

The only thing I can think of is this, but this is a bit more involved than just replacing the solenoids with a like stock part. This would only apply if you were trying to swap a later version of the 4L60E into your 95.

The 95 4L60E is unique, as the first version with a pulse width modulated (PWM) converter lockup. Later versions (96 and up) were PWM, but used a different 3->2 downshift solenoid. Some people claim you can use the later trans in the 95 if you swap in the correct solenoid, and control valve. But this is not correct.

All this comes out of this excellent reference:

LTXTECH Forums

Bottom line, I agree with Rob/Shoebox.... in-kind replacement should not be a problem requiring flashing the PCM.

Gasmachine85

Phone changed ecu to efi, sorry for the confusion, lol.

But yeah it didn't make since having to reflash for a stock replacement part.