Just picked up a non-running 996; where to begin?

[Loren]

A Porsche diagnostic tool will tell you if you have pending faults and exactly which emissions area is failing.

[Bay Arean]

Interesting update on the ABS/PSM issue. I dug into the electronics around the various brake/clutch switches. In a manual, I looked up the details on the Brake Light Switch and found that there are three wires: a signal going in (blk), one NO contact (blk/ye) and one NC contact (blk/rd) going out. These should oppose continuity at all times. Using a multimeter, I found that my switch didn't do that correctly. Instead, my switch had four contacts, with two pair being opposing NO/NC. See hand-drawn sketch below.

 

The part number on the switch was 96312343, which seems to be some generic p/n; certainly not the correct Porsche p/n. My research says 996-613-113-02-M100 is the right one. Correct one is on order from Pelican.

 

The PO had it switched in December; the shop must have used the wrong part but since the brake lights still worked (one pair of contacts was correct) they left it. Hacks.

Edited August 25, 2015 by Bay Arean

[987_RDC]

The first diagnostic was at the smog center; the technician told me 3 systems weren't ready. "Go drive around, at least 100 miles," he said. 200 miles later, here I am.

Next I used my buddy's USB "PCM Scan" tool. It allows you to see the readiness flags for each module, as well as pull trouble codes. It doesn't show any faults.

But I used a real Durametric to get the ABS/PSM fault code earlier today.

 

Hey let me know if you need access to w PIWIS to resolve. Good job on the rebuild.

[Bay Arean]

The new brake light switch arrived from Pelican today. I tested the contacts and they behaved as would be expected from the wiring diagram. Got on the highway, and sure enough -- no PSM/ABS fault lights and the cruise control worked again! So the conclusion was: in December 2014 the switch was replaced with a similar one but with different internal wiring. One of the two contacts worked correctly, causing the lights to activate but the computer to know something was wrong.

 

I also tried the "OBD Drive Cycle" again, this time beginning with a cold engine. Followed the instructions to a T, and it was successful. My buddy's scanner showed all systems ready. I'll smog it this weekend.

 

Looks like this project is just about wrapped up!

[GromitInWA]

Nice!!!

[AWDGuy]

still running?

[Bay Arean]

As far as I know! I sold the car to a nice guy in San Francisco. He had worked on older cars before and seemed to really appreciate its character, so I think it's gone to a good home. In the end I put around 3k miles on the Porsche. How's the Baum tool treating you?

[AWDGuy]

haven't touched it since I bought it. hopefully in the next month or so