2005 Crossfire Limited Roadster

I'm having an issue with the cruise control. Am I correct to assume that all you need to do to turn on cruise control is either move the lever up or down to SET it at the speed you're currently at? I did that, and it never SET. When I moved the lever UP to the ACCEL/SET position, and you could feel the car try to speed up (ACCEL). But it never locked in the speed.

The only thing I can think of is that I currently have my winter wheels/tires on which don't have pressure monitors. So technically the car thinks it has 4 flat tires, right?

Anybody seen this before? I have seen it work before, but havent' tried it in months. Any help would be greatly appreciated. Thanks!

 

I think you pull toward you to turn it on. I'll have to check, but there is no display telling you it's on.

 

To turn it on you have to pull towards you like flashing your high beam. To accelerate push up like making a right turn, to slow down push down like making a left turn.

 

You are correct FP; Pull toward steering wheel to turn on, push toward the dash to turn off


Stay Safe...


Respectfully,


Paul (MisterTaz)

 

Mine turns on by pushing the stalk up or down, in addition to pulling back.

 

I'll check the Owners Manual, but

UP is Set/Accel.

Down is Set/Decel.

Back (towards the driver) is Resume. And

Forward (Away from driver) is Disengage.

 

'To accelerate and set a speed, lift the lever up. Lift and
hold the lever to accelerate, or lift and release to set a
speed. To decelerate and set a speed, press the lever
down. Press down and hold the lever to decelerate, or
press down and release to set a speed.'

From the 2005 Owners Manual.

Push it towards the dash to switch of this function.

 

Yep,

I have it as a .pdf and can't cut and paste just pages 88,89 and 90.

There it is.

 

Yup, I tried up, down, towards, everything. holding, quickly tapping it, etc... And nothing would set the speed. Any other ideas? I was definitely doing the right thing to set it... multiple times, and multiple ways. But when I let off the gas, it just coasted down in speed instead of holding the set speed.

 

To copy text in the .pdf file use the 'copy text' button in the tool bar, and copy to the clipboard and then paste into the message window on the forum.

 

Try the fuse first, #10 under the hood in the accessory box. It is always best to look for a simple solution first if not then the following is from the Repair Manual. By the look of it the problem get harder to solve.

'Control of the speed control system is accomplished by a
speed control switch (1) which is located just above the multifunction
switch (2). The speed control system also uses other
components of the vehicle to accomplish its tasks. The five
other major components used are as follows; The PCM, Accelerator
Pedal Position Sensor, Kickdown Simulator Switch,
Throttle Body and the Clutch Pedal Position Switch (Manual
Transmission). The speed control system is designed to operate
at speeds above 25 m.p.h. (40 km/h).'

Good luck.

 

Now that I think of it, was it Franc Raucher that warned us of early failure of the servo for the cruise control being a Mercedes problem?
I hope it's not, but you might do a search for "servo" and take a look.

Just a thought...

 

Just a crazy idea!

Have you checked the fuse?


Edit; Good catch, onehundred80

 

Note: A cable and a vacuum controlled servo are not
used. This is a servo-less system.

Control of the speed control system is accomplished by a
speed control switch (1) which is located just above the multifunction
switch (2). The speed control system also uses other
components of the vehicle to accomplish its tasks. The five
other major components used are as follows; The PCM, Accelerator
Pedal Position Sensor, Kickdown Simulator Switch,
Throttle Body and the Clutch Pedal Position Switch (Manual
Transmission). The speed control system is designed to operate
at speeds above 25 m.p.h. (40 km/h).

The above is straight from the Service Manual, no servo's used.

 

I had this problem about 3 weeks ago. What worked for me was pull the positive on the battery cable for an hour and then when you start to use the cruise, start at a low speed and bump it up a mile an hour every few seconds or so until it quits. Then accelerate way above that and then back down to where you started and repeat until you get it to go all the way up to wherever you want the cruise to stay the highest. YMMV

 

Wow, that sounds quite confusing. And I couldn't get it to set at any speed. I think the lowest I tried was 55mph or so. Same thing, nothing. If I held it UP to the Accel position, you could feel it open up a bit and try to accel. But quickly returned to normal and never set the cruise.

Any other thoughts?

 

There's also a sensor tied to the brake pedal - not sure how it's wired in. I had a similar issue with the cruise not working on a Land Rover, and it ended up being that the brake pads had worn down causing the brake pedal to sit lower, which kept turning off the cruise.

 

Now that's interesting. 32k miles on these brakes. Driven by my wife (ie - accelerate to a red light, act suprised that you see a red light, proceed to mash the brakes like andre the giant and pray the car stops in time). No vibration or squeeling yet on the brakes, but they could definitely be worn. I'll try pulling up on the brake pedal next time I'm in it.

Thanks!

 

Brake pedals are returned to a stop by a spring, the brake pedal height is not influenced by the wear on the pads, any extra fluid required to make up the volume that has been increased by the pistons position is made up automatically by the reservoir on the return stroke of the master piston in the reservoir. Failure of this spring would allow the pedal to drop and imitate the pedal movement that switches off the speed control, that would be a doubtful reason though, but who knows.
As the speed control switch appears to accellerate the car, I would think that what is stopping the system from setting the speed is something to do with a signal that says the brakes are in use, the minimum speed has not been reached, or that the car is in park. Is there something amiss at the throttle body motor which presumably is the component that holds the speed? I shall keep looking, but I can see it is a real puzzle.

 

180,

I just can't let this pass. A servo is any electromechanical device that uses an external programming signal to control another device. Trust me, a vacuum motor while a servo, is not the only servo.

In your last post, you mentioned "the throttle body motor". That, too is a "servo".

Truely.

Back on topic:


And, after I poked aruond on mbworld, the question of tire sizes came up. Are yours OEM, or have you changed the sizes?