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03 4t65e won't shift unless I let off the gas

17K views 13 replies 7 participants last post by  04DetroitLS 
#1 ·
After reading all 16 threads with the word 4t65e in them. (really that's it?)
All the tranny problems come down to solenoids which is fine, but they all talk about hard shifting or bucking.
My problem is mine doesn't want to shift unless you let off the gas, otherwise it wants to wrap out.
Tranny fluid is still pink.
I mean I can do the usual solenoid replacement but even google doesn't seem to come up with anything with these symptons for this tranny?

Just a thought is there any other sensor it might be not on the tranny, like a TPS or something?

Only codes are random misfire and egr. (yeah the engine has issues too but that's another story)
 
#2 ·
Only codes are random misfire and egr. (yeah the engine has issues too but that's another story)
Just from what you stated here and what I learned from a transmission specialist 2 months ago says you are looking at the wrong problem. Skip the transmission for the moment. The transmission specialist told me that most times when the transmission won't up shift properly but as you described is due to a problem(s) with the engine. The engine has to lug harder (even if we as the driver are not aware of it) when it has an issue and this will cause the transmission to shift late or once the accelerator is backed off of. Since yours has the misfire and egr problem I would solve these issues first then see if the transmission really has a problem, for I doubt it does.
 
#4 ·
To solve those I have to do yet another head gasket, LIMG replacement.
That should solve the problem with the transmission. The PCM uses the MAPS sensor to help it on both the fuel trim and when to shift the transmission, with the reading off from the leak this would explain why the transmission does not shift until you back off the accelerator.
 
#7 ·
Get an emissions test done. Should indicate wether the Cat is bad, which I would suspect with sluggish shifting.

And don't replace the cat with an aftermarket if it is bad, and you have high emissions standards in your area. Oftentimes aftermarket cats are high-flow and do not do the job sufficiently to pass e-testing, even when new.
 
#8 ·
If that doesn't come up with anything, I'd be looking at the TCC solenoid.
 
#9 ·
Similar issue here, however it shifts when under 'normal' conditions, however when you 'hammer down' to pass someone, it downshifts fine, then won't upshift and it hesitates in/out of the throttle, the CEL starts to blink, and when you let off the gas, it will finally upshift. Then the CEL continues to blink for a short time and goes out.

This is on a 2002 3.8L auto with 78k.

Thoughts?
 
#10 ·
If the CEL is blinking, it's indicating that there's a misfire. Get the codes read. In your case I'd be looking at the cat.
 
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