What's This?

[Pero]

Hmmm, I have this switch, manual trans and ACC.
But ACC it's not disengaged when I press the clutch.
I can change the gears without disengaging the ACC.

Sponsored

 

[Vlad Soare]

Likely because the car needs to know if the clutch is all the way in or partially in. Bad things happen starting a manual with the clutch partially engaged. The switch at full disengagement gives the go ahead to start the motor. When driving, partial clutch will disengage the cruise. Two different functions, two different switches.

Indeed, that makes perfect sense. How didn't I think of that?

The clutch is in the resting position. So you would think that if this switch was working in conjunction with the cruise system that it would be on the opposite side of the activation arm (on the left) It would appear as though the switch in question is for detecting when the clutch pedal is pressed all the way in. Is there another switch?

I can't tell from this picture, but mine, after I put it back, sits in such a position that the extended plunger is very close to the pedal, and it starts being pressed almost as soon as the pedal moves.

 

[StangTime]

Indeed, that makes perfect sense. How didn't I think of that?


I can't tell from this picture, but mine, after I put it back, sits in such a position that the extended plunger is very close to the pedal, and it starts being pressed almost as soon as the pedal moves.

Is was borderline too cold to drive the Mustang on those MPS4 tires today but I did anyway. Out on the highway I set the cruise control. Clutch slightly depressed, cruise stayed engaged. Clutch half way, still engaged. Full clutch in and it took a few seconds to disengage. So I was completely wrong about how the switch and cruise works. Looks like only one switch is doing the work. Maybe the Euro cars have a different setup. There are lots of regulatory differences between NA and EU. I don't get how you were able to even start yours with that switch laying on the floor if it's used for both cruise and starting.

 

[Vlad Soare]

Now you've made me curious, so I took it for a short drive on a nearby highway and used the cruise control.
As soon as I just touch the clutch pedal the cruise control stops working (revs decrease and car slows down), though on the instrument panel the cruise still appears active. It doesn't matter how far down the pedal is depressed. Just a bit is enough. When I release the pedal completely, it immediately accelerates to the previously set speed.
In other words, the ACC doesn't deactivate per se (i.e. it doesn't appear greyed out on the instrument panel), but it does temporarily suspend any activity.

I should have done the same test before mounting the switch back. Then we would have known for sure. But now it's too late. After all the pain I went through yesterday to put it back, I'm definitely not going to remove it again.

 

[Elp_jc]

Is there another switch?

When you get under the pedals, it's very easy to tell if you have 1 or 2 switches. The bottom one will be there for sure, or you wouldn't be able to start the engine. The other's place is at the top of the clutch travel. If the switch is not there, you'd see an empty round hole, and a yellowish round rubber pad (which I also replaced with black Toyota ones, which will never dry out and fall off), which I'm using as a spare. I replaced the other clutch pad and the brake pad as well, and kept a 4th in my garage as a second spare.

Finally, maybe early 2019 cars have that switch, and late ones (like mine), don't. But it's obvious by now it's not necessary to have it. By the way, the start switch is not doing anything for CC, since the rpm are cut off by other means before clutch disengages. Otherwise, revs would shoot thru the roof momentarily before hitting that bottom switch. The digital dash shows which gear you're in, but forget about that, since cars without the digital dash, also have rev-match, so the ECU obviously knows which gear the tranny is in as well. The difference has to be something else.

Sponsored