Cruise set won't work

[BmacIL]

I've had an issue for the last couple months that I'm really scratching my head over. I can turn the cruise control on and off, and they grey LCD icon comes up in the cluster when I turn it on. The problem is that when I try to set a speed, nothing happens. I have replaced the clutch switch, I have removed and reloaded known OK tunes, and I just replaced the steering wheel controls for cruise control. Nothing. I've used a diagnostic tool to look for and clear any codes in the various modules outside of the PCM, no issues. At this point I have no idea what the problem is. It's not brake lamp switch, either.

Anyone got an ideas?

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[Deleted member 35786]

Perhaps this might help. Seems the tune was the culprit.

https://www.mustang6g.com/forums/threads/cruise-control-not-working.104208/#post-2256380

 

[BmacIL]

Perhaps this might help. Seems the tune was the culprit.

https://www.mustang6g.com/forums/threads/cruise-control-not-working.104208/#post-2256380

I saw that, and no, not the same. My cruise light turns on, his didn't. When I press set, nothing happens, so there's some sort of inhibit that it's seeing. All the obvious stuff has been checked off the list.

 

[Deleted member 35786]

Sorry to hear. Let us know what the fix is when you find out.

 

[BmacIL]

So I figured it out with my handy scan tool. Clutch pedal switch (even this one I replaced a few weeks ago) is showing partially pressed even when the pedal is not being touched or when I pull out the switch plunger to its extended position. It could be the switch, but I'm leaning more towards the wiring.

 

[BmacIL]

Update! There are TWO clutch position switches. One is for starting the engine (the one I have replaced), and detects whether the pedal is all the way down. The other is literally referred to as the Cruise Control Deactivation Switch in the shop manual. That one detects when the pedal has moved any amount off fully up, and is appropriately named. The part number is 4M5Z-11A152-A in case anyone ever runs into this issue. Looks like it will require taking a few of the trim panels out around the steering column in order to get access to it, but doable.

I verified on another S550 with my scan tool that the correct state of the PID when the pedal isn't touched is 'Pedal released'. Mine currently says 'Pedal partially pressed' when it's released, or when it's in any position but all the way down, at which point it shows 'Fully pressed'.

 

[BmacIL]

Plot thickens further: upon inspection, the switch isn't mounted! It's dangling up there and not touching the pad that's supposed to be compressing it's plunger. At least this definitively solves the riddle of what is the cause.

 

[Deleted member 35786]

Plot thickens further: upon inspection, the switch isn't mounted! It's dangling up there and not touching the pad that's supposed to be compressing it's plunger. At least this definitively solves the riddle of what is the cause.

Good to hear!
Interestingly we had the same thing break off on my sons old Honda rsx clutch pedal many years ago. The stop pad is plastic and it was rotten from being so old. We fixed it, eventually sold the car.

 

[BmacIL]

Good to hear!
Interestingly we had the same thing break off on my sons old Honda rsx clutch pedal many years ago. The stop pad is plastic and it was rotten from being so old. We fixed it, eventually sold the car.

Just hoping the mounting isn't broken, and just the switch... Otherwise I'm taking the entire brake & clutch pedal assembly out... Ugh.

 

[BmacIL]

Fixed today. I had to take off the left side trim panels and the knee airbag (as advised in the service manual), but I was able to get the new switch installed. Cruise is back working again.

 

[GT Pony]

Update! There are TWO clutch position switches. One is for starting the engine (the one I have replaced), and detects whether the pedal is all the way down. The other is literally referred to as the Cruise Control Deactivation Switch in the shop manual. That one detects when the pedal has moved any amount off fully up, and is appropriately named. The part number is 4M5Z-11A152-A in case anyone ever runs into this issue. Looks like it will require taking a few of the trim panels out around the steering column in order to get access to it, but doable.

I verified on another S550 with my scan tool that the correct state of the PID when the pedal isn't touched is 'Pedal released'. Mine currently says 'Pedal partially pressed' when it's released, or when it's in any position but all the way down, at which point it shows 'Fully pressed'.

Good job on trouble-shooting with the scan tool. How many PIDs show up on the S550? I have a good Actron scan tool and need to plug it in to look at what I can see on this car.

 

[bay584]

Fixed today. I had to take off the left side trim panels and the knee airbag (as advised in the service manual), but I was able to get the new switch installed. Cruise is back working again.

Hey @BmacIL was your hill start assist not working too? I think I have the same issue as you but I had also replaced my rear hub assembly around the same time so I'm trying to diagnose my issue.

 

[Whipplemock350]

I fixed my issue, at first the green light would come on and it wouldn’t set. My brake sensor was at fault. There’s a cheesy rubber stop that pushes the brake sensor button in and it fell apart due to the heat over time. Put some magnets in there with some hot glue as a solution and cruise control works perfectly fine now.

 

[Heggs550]

I just replaced my clutch master cylinder and I'm getting a no start situation unless I press the both brake and clutch and hold the start button through the entire cranking process. Then I get the wrench light that says see manual. Everything works fine otherwise. I just picked up a replacement clutch switch (lower switch), but I really don't think that's my problem as the fuel pump still primes when I press the clutch pedal in and I inspected/cleaned the switch.

@BmacIL , can you share some more info on where exactly to find this other switch please? I had the clutch pedal at both ends of the spring's travel during the process and I'm thinking I may have broken/dislodged the second switch.

 

[Heggs550]

I just replaced my clutch master cylinder and I'm getting a no start situation unless I press the both brake and clutch and hold the start button through the entire cranking process. Then I get the wrench light that says see manual. Everything works fine otherwise. I just picked up a replacement clutch switch (lower switch), but I really don't think that's my problem as the fuel pump still primes when I press the clutch pedal in and I inspected/cleaned the switch.

@BmacIL , can you share some more info on where exactly to find this other switch please? I had the clutch pedal at both ends of the spring's travel during the process and I'm thinking I may have broken/dislodged the second switch.

Nevermind, was super easy to find and access without removing anything. As I had anticipated, that upper switch (cruise control deactivation switch) was popped apart. Unplugged it, looked it over to make sure all the pieces were there, reassembled it, and put it back in.

Unfortunately, this somehow didn't fix the issue. Both switches are very simple units and I'm pretty confident they're both working as designed, but the damn thing still won't start without pushing the clutch and brake to start. Going to try to reset the PCM again, but other than trying to hunt down a fuse, this is getting a tad frustrating.

@BmacIL how were you able to access the PIDs to confirm the switches were/weren't working? I've got both FORScan and a BT OBDII receiver with Torque Pro. Damn thing isn't saying no fault codes even when the wrench light is displaying.

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