Ken D

Have you called all of the breakers/used parts dealers to check availability and pricing?

Don't know where you are located, but here in the States there's DC Automotive, Parts Heaven, EASY, to name a few of the well-regarded resellers.

DonnyV

Thanks, Ken. I'm looking into those place today.

njansenv

There was a fellow here on rennlist who was parting out his C4 - I've seen a few of the computers over the past couple months sell for about that price.
I'd consider trying to duplicate the Lightweight c4 setup (manual diff adjustment) or converting to a C2 before paying the $4k for a new ABS computer!

Alternatively, drive it without the computer until you find the right deal - the car drives just fine without it, though there are mixed feelings about driving without ABS that I won't go into here.

Finally, depending on how bad the corrosion is, bba reman might be willing to fix it.

boxsey911

DonnyV, I'm presuming that you get the ABS warning light and the sound of the warning buzzer? If so, that tends to indicate a faulty control module (that you're looking for) or a bad ABS relay in the fuse panel (I presume the shop has checked this) or a bad relay on the ABS pump (as mentioned by Campoj2) or a problem with a wheel sensor.

If you don't get the ABS warning light and buzzer but get the wheels locking up (i.e. no ABS) it's likely to be the ABS pump (you don't get warnings because the controller isn't intelligent enough to detect a faulty pump).

Ideally you need the Bosch ABS testing system to check it all out. Unfortunately, these are few and far between...you need to find a specialist that has one.

DonnyV

boxsey911 - Yea, I get the light/buzzer. They said water damage to the abs control module so I'm assuming thats it.

https://rennlist.com/forums/images/icons/icon9.gif

PAOLOP

I had tried at Porsche Center with originals tester but .... no answer

DonnyV

njansenv, Who's parting out their C4?

Also, can you explain what you mean by "duplicating a lightweight c4 setup"

My car is actually driving as a C2 right now. I'm not exactly sure how/why it's running as a C2 but that's what the mechanic told me. Apparently is would cost 5-7k to convert it back to AWD. I have a call into the mechanic today and I'll ask for details about that.

njansenv

https://rennlist.com/forums/parts-ma...990-964-a.html

Your car isn't really operating as a C2. AWD is operating at the fixed 31%fwd 69% rwd with an open rear diff. Many seem to prefer this setup at lapping days - they turn PDAS off by turning and holding the diff lock switch.

The lightweight used manually adjustable "master cylinders" to provide fixed oil pressure levels to the diffs. (rear and "middle")

I'd try to find out what is "C2" about the car - I'm assuming it's only due to the abs controller connection - if so, 5 to 7k is....expensive. How are you at DIY?

DonnyV

Thanks for reploy, Njansenv - The car is operating as a C2 because some part in the driveline (i think) broke a while ago and as a result it's operating in RWD. I'm still not sure which part of the car it is but I'll report back when I know. I don't think the ABS control module has anything to do w/it though because it was driving normally before any of the ABS issues popped up.