Cruise Control Issue

[opinwyd]

Been dealing with this for awhile, and just wanted some thoughts. Cruise control on the 01' 996tt doesn't turn on at all. Wont set the speed and won't light up the light on the dash. I am thinking that the culprit may be the red plastic clutch pedal switch with the plunger on it. The reason is because I am able to start the car without depressing the clutch. Before I buy a new one, just wanted to get a consensus from you guys, and or if you knew a way to test the switch first? Also I read that there are two switches for the clutch, but I couldn't seem to locate the "grey" colored one I read about?? Thanks for any help.

[JFP in PA]

Item # 17

[Ahsai]

Been dealing with this for awhile, and just wanted some thoughts. Cruise control on the 01' 996tt doesn't turn on at all. Wont set the speed and won't light up the light on the dash. I am thinking that the culprit may be the red plastic clutch pedal switch with the plunger on it. The reason is because I am able to start the car without depressing the clutch. Before I buy a new one, just wanted to get a consensus from you guys, and or if you knew a way to test the switch first? Also I read that there are two switches for the clutch, but I couldn't seem to locate the "grey" colored one I read about?? Thanks for any help.

That made me believe that your clutch start lock switch #16 in JFP's diagram above is SHORTED inside. It's a micro switch with a metal lever on it when pushed (by the clutch pedal when depressed fully) the two terminal are shorted. But when the clutch pedal is not depressed, the two terminals should be open circuit. You can remove the two connectors on the switch and put an ohm meter on the terminals of the switch. Then push the clutch pedal all the way down to test. If you remove the two terminals, you should NOT be able to start the car either.

Edited February 19, 2014 by Ahsai

[Ahsai]

http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement.htm

Yellow arrow in the 1st photo...courtesy of Pelican :)

Edited February 19, 2014 by Ahsai

[opinwyd]

Pelican is the best. This was the exact photo I was going off of when I was looking for it. I was thinking the same thing, but I looked for it forever and there is nothing there, no switch. My car is a grey market car so maybe the european ones didn't come with it? I thought maybe it was from the moron previous owner removing it, but I am not seeing the wires for it either?

Edited February 19, 2014 by opinwyd

[JFP in PA]

Pelican is the best. This was the exact photo I was going off of when I was looking for it. I was thinking the same thing, but I looked for it forever and there is nothing there, no switch. My car is a grey market car so maybe the european ones didn't come with it? I thought maybe it was from the moron previous owner removing it, but I am not seeing the wires for it either?

Having to depress the clutch to start the car is a North American trait mandated by the Feds to keep the unwary from driving through the back wall of their garage and into the family room because they forgot to depress the pedal. Been that way since the late 1960's. A grey market car would not have it.

[Ahsai]

Makes sense. I just assumed your car is a normal US car.

[opinwyd]

Well I guess I'm back to the red switch then being the problem..

[skymast]

I had this problem in my '02. The dealer told me I needed a new instrument cluster ... which i was unwilling to pay for so I just left it alone. i will be interested to see if thss solves your problem.

[Gottspd]

I had the same issue with my "red" switch. What I found was that the plunger in the switch was shoved all the way up, so it wasn't working properly. I pulled the plunger back into place and I'm happy to report that for the last several days, my CC has worked perfectly. It's worth a try. You'll need to pull the plunger apart, but it's easy to do. Reply back if you need assistance in doing so.

[opinwyd]

I was going to order a new part today, although it appears to be working fine by sight. The plunger functions, that is why I was curious if there was a test I could perform to try and confirm it was faulty. I find it so weird that there is no clutch ignition switch on the car, but like I said I just can't get the cruise control to work at all.

[Richard Hamilton]

If you could get it plugged in to a PST2 or PIWIS you could read all the switch input signals relating to cruise control. The brake and clutch switches have two sets of contacts in them (normally open and normally closed contacts) and both need to operate correctly for the system to work.

[GMD]

I bought my 03 996 in December and the CC wouldn't turn on either.  After much research, it appears the previous owner let the battery go down to the point that some of the commands on the DME were deleted.  $150 later, Porsche NOLA got into the programming and turned the CC command back on and it works perfectly.