Has anyone figured out what the switch is on the gas pedal when it is pressed all the way down? You really have to press very firmly at the end of the pedal travel to get it to actuate. Is that part of the circuit that resets the behavior of the pedal when the reset procedure is performed? (https://www.crossfireforum.org/forum...ht=accelerator)

I did not notice this on my 6-speed Crossfire that I just traded in.

Searched and couldn't find anyone talk about this yet.

 

Anyone?

I looked this evening at the base of the gas pedal, and sure enough, there is a button like switch that gets engaged when the pedal is fully depressed.

I am fairly confident that my non-SRT 6 speed did not have this.

What is it?

 

I'll bet its a kick-down switch. That lets the PCM know that the driver has mashed the loud pedal and signals the transmission to drop down a gear or two for faster acceleration. Just a SWAG on my part, but I would imagine cars with the automatic will have it and the 6-speeds won't.

 

That sounds right. BMW has had that same thing in it's automatics. Not on the manuals though.

 

It is not a kick-down. The transmission kicks down at positions much earlier than fully depressed.

The old GM TH400 auto had its kick down mode induced by a switch, but that is not the case here.

 

It's a kickdown switch. Check the service manual pages 21-339, 8W-15, 30, and 33.

 

Wow. That's bizarre. My transmission kicks down well before the pedal even gets close to the switch.

Wonder why the switch is needed when the computer can calculate the kick down from parameters like throttle position, speed, rpm, and current gear?

Maybe it is a last resort...if the computer's shift algorithm fails to send a downshift signal to the trans when the pedal is 99% floored, then the switch actuation at the last 1% finally sends the message.

Oh, and I need to get that darn service manual...I bet it isn't cheap!

 

Do a search the manual is posted.

 

Its a kick down for the lowest gear possible for maximum acceleration. Yeah the car kicks down sooner without fully pressing the pedal to the floor but if you notice its a subtle kick down but if you press it to the point where it clicks the switch then you will notice a really strong kickdown for maximum passing power.

 

I'm not trying to be an a-hole... but if you don't know what it is in the first place, please don't tell someone who replies to you that it's NOT what they say it is... I mean how can you be sure it's not something if you don't even know what it is... so next time try to have a more open mind...

End of my rant...

I wonder if this is in the limited auto xfire... not that it would make a difference since i don't accelerate over 3,000 rpm ... at least for now until it reaches 3,000 miles.

 

Bobs and Bullfrog are right. I stand corrected. It is a kickdown switch.

I finally got most of it figured out. Here it is:

1. If the car is going slow enough to down shift two gears without over-revving, then the first kick down is computer initiated and the second kickdown is initiated by the switch.

2. If the car is going too fast to downshift two gears without over-revving, then the kick down can be activated by either the switch or the computer.

For the second case above, I think the rule is this: The 2 to 1 downshift is actuated by the switch, and the other downshifts (5-4, 4-3, and 3-2) are activated by the computer.

I am not sure if these are all absolutely true, but my 2 hour drive today revealed no cases that contradicted any of these observations.

Still not sure why they couldn't do both kickdowns with software instead one with software and one with a physical device…them crafty Germans must have a reason!

 

Hey Guys, have a look at page 2,322 and 2,323 of the Service Manual where the throttle pedal operation is described. The switch is referred to a 'kickdown simulator' but...

"The kickdown simulator is not used as a “kickdown switch”. Wide Open Throttle (WOT) recognition takes place over
the signal from the accelerator pedal position sensors pressure point, which is located in the pedal assembly. WOT
position is simulated before achieving the full load position."

The whole section is worth a read because it describes in detail the way the throttle response learning algorithm operates...

"The PCM recognizes how the accelerator pedal is being pressed and switches between a few characteristic curves.
Eighty percent of the engine’s power is achieved for a pedal travel of about 50% for an aggressive driver and about
40% for a conservative driver. There is no further difference felt above a pedal travel of about 90%.
The characteristic curve for a conservative driver is active after a long drive. Then the accelerator pedal must be
pressed down unusually hard to obtain a higher acceleration level."

Simon.

 

I was using a process of elimination.

Let's say I don't know what a steering wheel is. Then I ask someone what that round object that spins in front of me is. Lets say the reply is: "It is the brake". I can say it is NOT the brake because the pedal next to gas is the brake.

I just told someone that the steering wheel is not a brake, even though I don't know what a steering wheel is. See, you can tell people what things aren't, even though you don't know what those things actually are.

This method failed me here because I assumed there was only one method for a kick-down, when in fact, there is two.

And we all know what happens when we assume...!

Point taken, PureVim, about having an open mind. If I did, I probably would have figured it out sooner.

 

What is the deal if you mash the pedal & it doesn't kick down at all? Getting on the freeway at about 40 MPH, I floor it & it doesn't down shift. It feels like its in 4th gear & when the R's finally get up there... I feel the pull of power.
At first I thought my floor mat may have been in the way but it wasn't.
I'm going to take it in & have them look at the EGR Valve (and the warp speed button at the pedal too).

 

good luck with the dealer and the WARRRP SPEEED BUTTON is a good one!!!

 

Warp Speed Button. That's classic!

With the engine off, you can feel the click of the W.S.B when you mash down the throttle. In my car, I have to press fairly hard to get it to click, but it is very obvious when it does so.

Can you feel yours click?

 

I think that should become its official name.

 

Try the re-set procedure. It should clear all the parameters pertaining to throttle response stored in your computer.

 

And here is HDDP's reset procedure:


The Throttle is "Drive By Wire" and adapts to your particular driving style. Do a TBA Throttle body adaptation.

1. Get in your car, it doesn't matter if you close the door or not.
2. Turn the key to the on (not start) position, the position just before the starter turns over.
3. Press the gas pedal to the floor with the key in the "on" position.
4. Hold the pedal to the floor for five seconds, then turn the key back to the "off" position (don't remove the key), then release the gas pedal.
5. Wait 2 mins. for a full alignment.
6. Drive the car as you always do.

Depending on your driving style, this may or may not be a big factor. I do a lot of city driving so
I noticed a big change after erasing my history. It is not hard to do this, just follow the instructions -

Key on, pedal down, 5 sec, key off pedal up, wait 2
minutes.

Keep the key in for the entire thing.

If this doesn't work, disconnect your neg. battery cable for 20 minutes. This will re-set the parameters in the drive-by-wire... Unfortunately it will delete your pre-set radio stations, clock etc. as well...

 

Good info. Will do. Thanks!