transmission and torque converter question

[jeremeyndesy]

my 2000 v8 explorer has the 4r70w in it. my question is does this transmission have a lock-up converter or what? I thought my 98 gt which had the same
transmission. i thought it had a lock up converter. anyway from 60mph up the rpms never drop. usually on a lock up vehicle you could touch the brakes and the lock-up would disinguage! on mine it doesnt so im wondering does mine have a lock-up converter or has lock-up went out?:scratch:

 

[JK080]

Yes it should have lockup, may want to check it with a scanner to see if the computer is commanding lockup. Check for codes, the computer will set a code if it doesn't see lockup.

 

[jeremeyndesy]

if computer isnt commanding it to lock up what do I do

 

[JK080]

If the computer is not commanding lockup then we will want to look at the things that will keep the computer from sending the command.

Things like coolant temp, the computer will delay lockup to help warm the engine. So if it thinks its 20 below zero it will not allow lockup. Bad coolant temp sensor could be the cause, scanner info is the way to go don't go by the gauge, you want to see what the computer see's.

TPS sensors or MAP sensors, or any sensor that can determine engine load can cause the computer to release the converter, it may tell the computer that you are under load like climbing a hill.

Simple things like the brake switch, if the computer thinks your on the brakes it will release the converter, also check the rear light bulbs, a blown bulb can interrupt the TCC circuit.. its a Ford thing..

 

[koda2000]

BTW, if it's low temp coolant issue, you should receive a CEL and code P0125 and really lousy fuel economy, as the computer doesn't enter closed-loop mode. this can be caused by a bad thermostat or a bad coolant temp sensor.