pcar964

Little public service announcement here -

As my 95 993's odometer has stopped working, I have removed the entire guage (speedo/odo) and it's being fixed now and mailed back to me. I did this a few days ago, and I didn't intend to drive it at all until I got the guage back.

Long story short, I got the urge and went for a drive last night on some favorite roads of mine, very nice mix of sharp and sweeping turns... but the car didn't feel quite right.

Of course when you remove the guage, the cruise control won't work (it works off the speedo), and after driving about 50 feet the CEL comes on to tell you there is something wrong with the speedo. That was expected. What I did NOT expect was to have my rear brakes activating intermittently in the middle of an 80mph turn!

What I think is happening is that the ABD (auto brake differential) which is a form of traction control that measures wheel speeds and prevents slipping below 40mph in 993s, was activating even at 80mph because the car didn't know how fast it was going! I'm a little surprised the ABD woudn't automatically shut itself off if there was a speedo problem, because let me tell you it got a little hairy in the middle of that turn!!!



So the moral of this story is - don't drive your ABD-equipped 993 without the speedo in proper working order!!!

Greg in Florida

akolodesh

thanks for the update - didn't know that could happen

Davies

The ABD is connected to the speedo, so it knows not to activate over 30MPH.
Also,Tiptronic cars can't manually shift either, if the speedo is disconnected.

Another drawback is you can't tell how fast you're going. :-)

texas911

How many miles do you have on your car?

pcar964

I have just under 78k on my '95. Why do you ask, would that have any effect?

hawk993

Numb Nuts!

993Dave

Uh, Hawk, I think you meant to post that on the "weather's great in California" thread that was probably right next to this one. So, no offense meant to pcar964, right?

Davies

pcar964, These guys are giving you a hard time about the unlogged miles a disconnected speedometer can achieve.

God forbid cutting a new guy some slack.

hawk993

Just having some fun, sounds like something I would have done...LOL

pcar964

That's ok, I guess I deserved that :-) But now that you mention it, it would be surprisingly easy for someone to disconnect the odo to keep the miles down in these cars! I trust nobody on this board would do something like that though - I would hate to think the previous owner did that to me!!