What happens w/ the TPS??

[GodAmGT00]

I'm not sure if this should go into the "Talk," or "Tech," section so I threw it in here, since it has some technical aspects...

So I've been reading a lot of issues regarding people w/ Tranny malfunctions, and knowing a little bit of electronics from older cars, not necessarily Fords..


How does the TPS communicate w/ the rest of the engine controls, in terms of "Kick Down," for the Tranny?? Is there a "Cold Start" Sensor, vs. the Coolant Temp Sensor?? Is the MAF Connected to the TPS at all?


I don't have any electrical diagrams for anything newer than a 93 Foxbody (for Fords that is..). I'm just wondering for my own good. I know on older cars, TPS can cause the cars to not start, or to hesitate when Accelerating, or to just work intermittently..

Any info would be great..


JT

 

[Kilgore Trout]

TPS is the throttle position sensor. It senses the position of the butterfly in the throttle body. It communicates with the PCM (powertrain control module).

 

[GodAmGT00]

I figured as much..


I was looking for more info, like when it fails, what are some of the symptoms?? What other ancillary components does it directly affect (i.e. Trans Kick Down Sensor, MAF Correlation, etc..)

I'm just trying to get a better understanding of the 4.6/5.4 and there are still some things I'm totally in the dark w/.

Sort of off center but: Does the 4.6 have a Cold Start Sensor, or does it use the Coolant Temp Sensor, or even further, is there an Intake Air Temp Sensor??

Sor many questions...


JT

 

[Mike97gt]

read my sticky on the top of 4.6 tech.. this explains how the TPS works.

TPS is one of the most misunderstood sensors out there. Modern Ford EEC systems no longer need to be set at .99 at idle or anythign like that. in fact closed throttle voltage can be different everytime you start the car and this is still fine. The PCM will automaticly read the lowest TPS voltage it sees when you start the car and assume this is closed throttle. so anything between .53-1.27 is normal. all you want to do to check the TPS is make sure the voltage increases smootly as you open the throttle. Also you want to read the PID data and see if the PCM is swithcing from C/T to P/T to W/T mode.. c/t is closed throttle p/t is part throttle and w/t is WOT

The PCM also looks at the throttle angle rate, this pcm does use this as one of it's inputs to base transmission shift startegy on..

 

[GodAmGT00]

Hey svttech,

Great info, however as I was reading through, I had 2 questions...

- Throttle Angle Rate: What exactly does this mean?? Is it the rate at which you depress the accelerator??

- Maybe I'm confusing the terms, but I was under the impression, that when cruising, the car goes into a "Closed Loop," how is that different from "part Throttle?" Is there a timing that is pre-determined for "Closed Loop?"



JT