Robert Collins - 96 993TT

One problem after another....

My car will not pass the emissions inspection because the OBD II computer is saying that I have five monitors not set and therefore not responding. They are the catalyst, oxygen sensor, heated oxygen sensor, and two others.

I thought I read something on the board (but could not find it in a search) about people who got the wiring harness recall done on their car were having damaged OBD II units or units that were not responding to the new wiring harness for whatever reason. Does anyone know what the problem is or what I can do to fix it?

Here is the real kicker...I went to the director of vehicle inspection for Metro Nashville in Tennessee. He tested my car and it failed, so he said "your car needs more drive cycles since the dealer disconnected the battery so recently". So, I drove the car 900 miles and took it back to him. THIS TIME IT PASSED WITH FLYING COLORS!!!

So I take it over to the station to be checked so it will pass, and the damn thing failed AGAIN!!!! I go back to the director who checks it again, only this time it failed for him too. Then he said, "Well, I now know that your problem is your OBD II sensor is randomly losing it's memory, or there is a short somewhere between the computer and your engine, probably a loose or damaged wire or a bad fuse".

A bad wire?? This wouldn't have anything to do with the main wiring harness being replaced about 100 miles ago would it???....... to which he replied, "That's where my bet would be, since the wire to your OBD II is in there"!!! <img border="0" title="" alt="[Eek!]" src="eek.gif" />

So, now do I have a problem with a dealer who either improperly installed my wiring harness or worse yet, might have even damaged something when they did it? I am at a total loss right now and am really looking for some guidance.

Have any of you had this problem, or know someone that did and got it fixed?

Thanks for any help you can give. Hopefully we can all learn from this one to keep anyuone else from going through inspection TWELVE TIMES, only to get nowhere!! <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" /> <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" />

Robert Collins

Steve Weiner-Rennsport Systems

Hi Robert:

I'm sorry to hear of your troubles here, this can be very frustrating and in some cases, expensive.

Your car is having Readiness Code issues and this is not uncommon. As you have likely surmised, the car must be driven a requisite number of miles & cycles to clear those codes in the ECU and this is ususally 25-30 minutes after a cold start. Total miles is NOT the only criteria for satisfying the OBDII Readiness conditions that must be met.

I would drive the car in normal traffic for 30 minutes and then go immediately to the Testing Station. That will usually satisfy the Readiness Parameters that must be met and it should pass.

If the car's ECU will not clear its Readiness Codes after this, contact me directly for a solution. In most cases, we've had to replace the ECU with a new one, but I might have a loaner here for you to try,....

Robert Collins - 96 993TT

Thank you Steve. If it comes to that, I would really appreciate the "loaner". If that is ultimately what it is, do you think we would get any help from Porsche or the dealers, since this did not happen until the wiring harness issue came up? Just curious.

As for driving cycles, I have done a cycle that my mechanic gave me, as well as the 900 miles. I have driven in everyday traffic as well as highway, driven fast and slow, and have had many cycles where the car has gotten to driving temperature, then cold, then the same thing over and over again.

The good news is the director is going to pass me the old fashioned way this year, but if there is something here that is the liability of the dealer, I need to find out now rather than next year. I'll let you know.

Thanks again.
Robert

Steve Weiner-Rennsport Systems

Hi Robert:

My past experience with this has resulted in zero help from Porsche & its Dealer network. Perhaps you might have better luck, than I have had. We simply purchased a new ECU and that instantly resolved the problem.

One can read the Porsche OBD-II manuls to see what parameters checks off the Readiness Codes that are logged at each cold start and these cars MUST be driven at LEAST 20 minutes after cold start to clear those codes. After its up to temperature, it should pass with flying colors. If the ECU will not clear those codes after that, its time for another one.

I've gone around this merry-go-round situation too many times to recount.

You have nothing to lose by trying to see if Porsche might resolve this, or replace the ECU. Its now beyond the Factory and EPA mandated warranty period.

Robert Collins - 96 993TT

Steve,
If we get to the point of no return, what does it cost, parts and labor to replace a damaged ECU?? What is it really good for other than emissions testing? My car is running fine, so I know it won't be a "it won't start" problem, etc... Do they give you a core refund, or is the old unit only good for beating the Porsche NA regional service rep half to death with <img border="0" alt="[nono]" title="" src="graemlins/nono.gif" />

In other words, if this nice director would pass my car every year, would I ever actually need to replace it for other reasons?

Now to vent, how absolutely shi <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" /> <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" /> y of a fine car manufacturer like Porsche to NOT stand behind their own damn internal computer. My car has 31,000 damn miles on it. I think these federally mandated computer systems should either be equivalent to a rust/ corrosion type warranty (10 years, etc..) or life of the car.

I'm now off the soapbox. Sorry. I feel better. <img border="0" alt="[soapbox]" title="" src="graemlins/soapbox.gif" />

Robert

Steve Weiner-Rennsport Systems

Hi Robert:

In this case, the only reason one would consider replacing the ECU is to get the car to pass smog tests. In all other similar cases, the car ran fine otherwise, but simply would not pass and therefore could not be relicensed.

These run $ 1804 at the dealer and its very simple to replace it. If you wish to keep the immobilizer feature, a Dealer must install your codes in the new ECU. If you do not care, you may buy a replacement ECU without that feature. Your existing ECU would be a spare, or a trophy.

I agree with you on the warranty issue. There are no provisions for very low mile cars that in principle, ought to be covered in situations like these. You have nothing to lose by asking your local Porsche Service Manager if this might be covered. Porsche has been known to make an exception once in awhile.

Robert Collins - 96 993TT

Steve,
If I have to replace it, can you put in the ECU from a 1997 that is flashable or reprogammable? Would that keep this from happening again? Just curious.

Robert

Robert Collins - 96 993TT

Steve or anyone,
Hate to ask again, but can you or would you want to replace a 1996 ECU with a 1997 unit because it is flashable (reprogrammable)???

In other words: Would it be compatible with a 1996 car, and if it was, would the fact that it is reprogrammable be a plus in the problem I am having now?

Thanks
Robert

Steve Weiner-Rennsport Systems

Hi Robert:

You may indeed, replace your '96 ECU with a stock or reprogrammed '97 ECU with no worry and it will usually fix the problem, provided that there are no other issues.

IMHO, a '97 programmable ECU would be considered an upgrade to your car, expecially for someone who is performance oriented.

laurence '97 C4S

Steve-
I have to say it is incredibly nice of you to provide the kind of information you do. I read this thread with interest even though it's not relevant (knock on wood) for my car. Thanks.

Robert Collins - 96 993TT

I agree with you Laurence. I have watched Steve (as well as others like Viken, Robin, Dan, Robert, E.J., etc....) for a long time. They have always been unselfish with the amount of time they spend trying to help others with their expanded knowledge of these cars. My personal thanks goes out to you Steve, and all the other guys on here, Gurus or not, who always lend a helping hand.

Now to hopefully return the favor, the Director of Vehicle Inspection for Davidson COunty/Nashville in Tennessee called me on Friday and left me a message about there being some federal mandate that ECU's are covered under some type of warranty. I have not spoken to him yet, but will pass along any information I get to hopefully help others who run across this problem. What is actually cool about this, I did not even ask him to look into it. I simply told him the replacement was $2-3000 and that was alot for me to shell out simply because Porsche and the federal gov't. can't talk to each other through my car.

I'll report my findings. <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

Steve Weiner-Rennsport Systems

Laurance, Robert,.....

Thank you Sirs, for your kind words. I, like the other gentlemen, have simply tried to offer some objective, constructive, advice and assistance to those in need,..... I'm happy to help in any way possible.

I am quite pleased to hear of that phone message you received. I shall cross my fingers, toes (and eyes) in the hope that Porsche offers some assistance in this matter. Please keep everyone in the loop as this is not an isolated occurrance.

Robert Collins - 96 993TT

TO STEVE AND ALL CONCERNED:

New News!! I called the dealer after the phone call from the Director of Vehicle Inspection and they said it sounded like I should bring it by to have the ECU checked out since my ECU was RANDOMLY losing it's memory after each drive cycle. I will give credit to Todd, the service advisor I have at the local dealership, because he has been a total stud and very supportive throughout this whole ordeal.

Anyway, they check out the car and find out that I do in fact have a faulty ECU. Under the federally mandated "EMISSIONS PERFORMANCE WARRANTY", they tell me that Porsche will in fact replace it at no cost to me. WOW!!! Even though it is a federal warranty, it is still pretty big of a company to step up to the plate and back it up with no questions asked. I'll eat crow concerning Porsche for now. If you read the warranty book that came with your car, they do have a few "outs" in the warranty, but not for me.

Anyway, that was a minor victory, but now for the bad news. I picked the car up with the new ECU, and they tell me the readiness codes are still not setting. Possibly a few days of driving will set them. Over the next week my car starts having random electrical issues like the wing not retracting when I turn the car off, and the stereo just randomly turning off and back on at will when it is running. I call the dealer to notify then of this behavior and they tell me to bring it back in. Possible causes were a BAD WIRING HARNESS, or possibly the alternator.

They call me two days later and tell me they ran some tests on the car and the alernator was in fact running at 12.4 volts under load and was only putting out 40 amps. They sent it off to have it tested and ended up having new brushes and contacts (or something) installed. This brought the amps up to 60-80.

At this point, they have not gotten the readiness codes to set yet, but will try for a second time in the morning. My question to you guys is what else could there be if it is not the wiring harness. We have a new ECU, a relatively new battery, a repaired alternator and a supposedly good wiring harness. Any suggestions of things to talk to the regional rep or the dealer about would be helpful.

I will give credit to the regional Porsche rep, whoever he is, because he was quick to cover the ECU and is supposedly working closely with the dealer to resolve this issue without costing me a fortune. Who knows, maybe this is starting to become an issue for these cars and mine is the guinea pig.

As always, I'll keep everyone updated.

Robert Collins

Lorenfb

It's not clear whether you've had the harness
replaced or not. If not, have it done. This is a
major problem for Porsche and Mercedes
Benz. They both used the same harness
supplier.

Many of my customers (indep. shops in
So. CA) have had a real headache with
993's with harness problems and OBDII
emissions testing. I've seen some DME
units damaged by bad harnesses.

The main problem I've seen lately is secondary air passage carbon buildup.
Some of the dealers I also work with have
been doing valve jobs at 50K to allow
an emissions test pass, an expensive
fix.

You really need access to a Porsche ST2
tester to fully analyze your problem. I use my
tester often when working with 993's. It's
a must.

I hope that you haven't done any mods to
the F/I system. See my website (systemsc.com). It may provide some useful
info.

Bottom line!

1. Must have a new harness
2. Get access to a ST2 tester
3. Get a good alt. & don't just replace
the regulator
4.Make sure the battery holds a charge

Good luck
Lorenfb

Steve Weiner-Rennsport Systems

Hi Robert:

I'm very pleased to hear that Porsche stepped up and replaced the ECU under warranty. IMHO, that was the right thing to do.

As noted above, I'd have the wiring harnesses checked out very carefully.

Bear in mind that it takes at least 25-30 minutes of driving for the ECU to go through all the OBD-II parameters and clear readiness codes. After that, it should pass with no troubles.

Please keep me posted on the final disposition of this.