orcfromthesouth

I am having an odd glitch with my cruise control. Yes, I know....why would anyone use a CC in a 993. I only do it when John Law is out with the lidar. Its the only way for me to observe 75 mph.

Recently the CC doesn't 'hook up' at times. Stopping the car and starting the engine again cures it. Yesterday, for example, I was using the CC till I reached a toll booth. Then after that it refused to work.

I will chech the fuse for starters.

Any ideas?

Terry Adams

When I had this problem at about 30K miles, the dealer told me it would be a drop engine job so they could get to the mechanism. I told them I would do without it, so they "disconnected" it at my request, and for a $300 charge. Soon thereafter I did the Techron treatment just before a scheduled oil change. Then, just on an impulse, I tried the "disconnected" CC, and it worked. And has worked ever since. I theorize that the Techron treatment was just enough to clear out the ISV, which got the "disconnected" CC going again.

BTW, I occasionally use my CC for the same reason you do.

dhicks

I have the same problem....it works sometimes and not others.....is this a common fault.....what is an ISV????? Please excuse my ignorance

swftiii

Orc,

I had issues with my cruise control a year or so ago. Searching the archives can provide a significant amount of information and direction to start your search. Here is my original post when I had a problem with my cruise control.

https://rennlist.com/forums/showthre...cruise+control

I recommend checking the micro switches for each the brake and clutch pedal to make sure they are aligned and engaging properly. Also look at the pedal travel to ensure the pedals are coming all the way up - I think my problem had been that the pedals didn't come all the way back out due to the wooden floorboard.

Good luck and keep us all posted - pictures are always good for the archives.

Skip

akolodesh

cruise control??? Our cars have cruise control? Anyway to remove it?

orcfromthesouth

Thanks for the input.

Sorry for being lazy. Will search the site.

orcfromthesouth

BTW Didn't know the clutch switch had anything to do w cruise control. I guess it avoids someone from accidentally downshifting and suddenly having the CC going up to the programmed speed.

Olav A.

I've tried to turn on my cruise control a couple of times to no avail only later on during the drive it suprised me and turned on by itself.

Very weird.

I thought it was the Spirits in the material world.

swftiii

Orc,

Actually your statement about the cruise control and the clutch is incorrect. Cruise will turn off if the brake pedal is engaged. If the clutch is engaged it will temporarily turn cruise control off, but once the clutch is back out cruise control will take over again and adjust the speed.

Good luck on the search for the cause.

Skip

Bill 993

My cruise didn't work and it turned out that the switch on the clutch pedal required adjustment. The switch operates by turning off the cruise when the clutch is depressed. If it's mis-adjusted then it thinks the clutch pedal is depress and hence the cruise control never works.

Edward

Don't know if you have the "sticking clutch pedal" syndrome, but that will definitely keep the CC from engaging. Next time it refuses to work, make certain your clutch pedal isn't just hanging up (pull up with toe).

Edward

Lorenfb

The cruise control actuator (moves the linkage) can be a problem, if the unit
has not been used often. The actuator needs to be electrically "driven" directly,
i.e. bypassing the cruise control unit. The actuator has three key elements;
the motor, the clutch, & the variable resistor feedback. Both the motor &
the resistor may have become oxidized, i.e. the commutator & the thick film
resistor, respectively.

ventoGT

Apparently this is a somewhat common problem--on the way back from South Florida after just purchasing my 993, I had the cruise on on the Florida Turnpike [I just bolted my tag from my 996 onto the car, as Florida insisted that I pay tax to them when GA doesn't charge tax for a private sale--F that I say...] so needless to say I didn't want to be caught speeding. After I stopped for gas and a bite to eat, I went to re-engage the cruise and it didn't work.....I was pretty pissed after just getting the car and was hoping it wasn't some sort of omen. Well, I stopped for the night, restarted the car next AM, and cruise was working again...I have never had a problem with it since [knock on wood]

orcfromthesouth

Well, good to know I have company.

This is why Rennlist is worth every penny!! Just think of what a dishonest dealer can come up with if he's having a slow month!! Terry´s reckoned a drop engine job!

I do have the sticking clutch pedal syndrome. Will go in this week end. At least to check the microswitch adjustment. A friend who had a Beetle told me ' ahhh, used to have the same problem...' So I guess its part of the romantic part of my 993. I am getting to like the toe adjustment quirk. Don't expect any rationality. But I once had a Yamaha XT500. Kick start only. And there were those who knew how to kick the beast, and those who just flew over the handlebars.....Gave the bike that little extra 'uuuhh...ahhhh' factor. Same with the pedal.
Orc

hoggel

I haven't looked at the schematic for the cruise in the 993 but in a vw GTI the switch has two sets of contacts, one for the cruise control and one for the clutch/start interlock. I know because the switch fell out of the bracket on mine once and the car wouldn't start.