97 12v stock , trans 47re

What is wrong ?

I cannot get torque converter lockup at all in overdrive

With lockup switch I can only lock the conerter in third ( why only third not both third and overdrive)

Already replaced

TPS
overdrive solenoid
VSS

what could it be Torque converter solenoid? Temp transducer? The only thing that makes me think that the torque converter isn't toast is that it does
lockup in third gear. Am i wrong?

 

Bump..........

 

Instead of throwing parts at it why don't you take it to a tranny shop?
Any good shop will tell you what's wrong for free.

 

local tranny shop wants $95/hour just to diagnose and said a minimum of two hours, It just kills me to pay someone else to do anything for me , However I am now starting to lean in that directon.

 

so the tranny shop said i have two options
1 drive truck as is
2 rebuild tranny

I chose option one . funny thing is , two weeks later the truck one day decides to lock up in overdrive . but only that one time. it has been a week
and still no lock-up again
***

 

hi
install a lockup switch and if it locks the trany is good just need to find elect prob .
tps defective
no current to tps
fluid level filter condition
tran temp sensor bad
ect
go fishing !

 

I'm not good at 24V...But doesn't the 2001 throw codes?If it does maybe the truck will throw a code for the trans..

 

He mentions in his 1st post truck is '97 12valves 47re

 

Check the tranny temp sensor if it is reading too low computer will not let it lock up. Normally with this bad it does not shift into overdrive either.

You might just have a bad connection at the wireing plug on the tranny case.

 

Could be the brake light switch, too. Make sure it's working. Check the voltage at the TPS. Take a paper clip and shove it into the plug at the TPS to get contact. You want voltage reading from the middle wire. With key on and engine not running you want to see about 1 volt there. These are cheap things you'll want to eliminate as possibilities. Trans temp sensor is another possibility. Do a search for resistor/trans temp sensor. Basically you unplug the sesor and jump across the plug with a resistor you can get a Radio Shack. That makes the PCM think the tranny is warmed up to within the parameters it's looking for. Chances are good it's something cheap and simple.