After changing the TPS sometimes the car will not downshift and at times it will what could be the problem?

So what are you asking?

You shouldn't be replacing any parts
until you understand the systems & do
the testing needed to find a problem

The only parts that get installed are ones that fail a test
& are found to be the system fault causing the problems

Your work the codes one at a time & resolve them as you go

Transmissions have 4,5 or 6 speeds,as well as converter
lock-up in most speeds,there is no passing gear per/say

Codes do not indicate a need for parts or tell you anything is wrong

Codes are input computer sensors that report how the mechanicals
are doing,they can fail but they can also set codes & are not related
to anything.

You could have a sensor issue effecting shift strategy & you could
also have a failed transaxle, if it is original,over ten years old or
the fluid hasn't been changed every 3 years since new

use a code reader to reset the computer.

Thinking it's coming out of lockup not actually downshifting,
possibly brake pedal switch adjustment,TPS, or lockup solonid is
faulty. Notice how you can cruise at 60 and just barely touch
the brake pedal,it will come out of overdrive,you can feel it.
If you have a tach the lockup will only change the RPM about
500 ,if it was downshifting it would be more like 2000.

Hi.

You may have to replace the throttle position sensor.

The TPS is used by the TCM (transaxle control module) to determine when the gear is shifted. In your case the bad input from TPS is causing the auto transmission shifting at the wrong time.

A way to test the TPS is reading volts at sensor wiring while someone else operates the accelerator pedal, pushing it slowly and smoothly. If there are gaps or peaks in the volt reading , then the TPS is bad.

Please do not forget to leave feedback.

Regards.

Ginko.

Start with checking the TPS, A bad TPS will cause this type of problem. Make sure that the wire harness is good and if it is, then good chance that the TPS will need to be replaced.

change trans fluid and filter

sounds like the downshift cable is out of adjustment, or stretched out. the downshift cable goes to the transmission. CARL,

check computer ground in black and blue wire

Have the TPS checked for a possible erratic return signal.

did they lab scope the tps for intermiten week spots ??? it could have a open spot on the tps and the computer thinks its "idling" or "w.o.t" causing the wierd shifting. hope this helps...... jimmy