Resetting the Computer?

I have an 03 Boxster S with 25K miles on it. I just had my second engine check light in six months(less than 2000 miles). The first one cost me $650 at the dealer and I'm fairly certain I was robbed as it might have just been a gas cap.

Two weeks ago we had the engine check light go on in our Volvo V70 and when we took it to our Volvo specialist he just reset the computer saying that often they get a misreading and that there may not be a problem. He said that if comes on again then we should go further and diagnose the problem. A week later the light has not gone on so perhaps he was right and he saved us a fair amount of money.

Can the Boxster computer be reset as my Volvo's was? What equipment does it take to do it? If a mechanic or dealer does it what would be an appropriate charge?

Coincidentally, each time the check light has gone on I had been messing with little locking mechanism for the gas filler lid. The first time I was curious as to how it worked; I had just bought the car. The second time was last week when I was showing a friend how it worked. Maybe that little mechanism, which is electrically controlled, backcircuited into the computer. I know that's a pretty wild theory but I can't believe this is happening.

Jack

You need to get the fault codes(s) read to find out what is causing the CEL.
Many Autozone stores will loan you a reader to to check your car in their lot.
Codes can be reset with the reader - but as I said you need to find out what the faults are.

My local Autozone and Kragen auto parts stores no longer read fault codes claiming it has something to do with a violation of emission standards. Pep Boy's was the only store that would try to read them but after they hooked up their $1200 OBDII computer it did not have a program for Porsches. My CEL also came on twice and the second time I took it to a Porsche shop that had the PST2 (I believe that's correct) Porsche diagnostic computer and it cost me $62.50 to have the fault codes erased and the CEL turned off. So far I've driven through several cycles and the CEL hasn't come on.

An Actron $40-$100 code reader will work. Sure it doesn't know Porsche codes well enough to translate them into an English (or your native language) explanation but as long as you get the Pnnnn format codes there are those on the online forums who have Porsche manuals and who can translate them. The simple Actron will turn off the CEL...which is not the same as solving the problem that caused the CEL and is not necessarily going to get you through a smog check. You gotta fix the root cause for that.

Link has more info.

Mike I don't mean to belabor this topic, and although I agree with you about fixing the problem, jborchel brings up a point that is very often misunderstood by Porsche newbies (myself included although I'm learning) and appears to be taken advantage of by some Porsche repair facilities. In my instance I took my '99 Boxster to a renowned Porsche repair shop shortly after I bought it (no, I didn't know about your site and the info reg PPI). I paid to have an inspection done, replace rotors and have the 60K service done as the car had no Carfax record of it being done. I was also told that fault codes appeared indicating that my air bags and seat belt harnesses needed to be replaced ($1400) and emission codes appeared indicating the car would not pass smog and that major emission work needed to be done at the tune of around $1800. Now, I didn't know Porsches but I did know that the car had just passed smog when it was sold to me and even the owner of the shop questioned the mechanic on this who had no answer for why the car would pass smog in the condition it was in. The mechanic didn't write down the air bag and seat belt codes so he couldn't tell me what they were and since then have not appeared again. The codes that recently came up on my car, and turned on the CEL, once erased indicated that the car was running well within emission standards on the Porsche computer. I've had the car smoked tested and liquid tested for intake leaks and none were found but the shop in question (the original shop I took the car to) wants me to pay for them to do it. I've been told that the O2 sensors should be replaced, then told by someone else that it is rare for them to go bad. I've been told to replace the MAF but no codes for the MAF are appearing. I've been told it could be the secondary air pump system and that should be tested because codes are coming up indicating it may have a leak.
Hopefully you see where this is going and understand that it is very difficult to separate the intent of what these codes represent. Is it a failing part or one that has failed? Does the fault code that appears point to a specific part or to an entire system and what should one pay for testing the part or the system? If a part has failed should just the part be replaced or should the system the part is in be replaced? I won't go on with this but hopefully you understand the frustration (and that is why you put together your site) in trying to deal with fault codes.

Offshore,

Your experience that you described is very similar to my first experience. The process that the dealer went through was very much a try this try that technique that eventually solved the problem. Unfortunately I had to pay for all of the labor hours to find it. Then, to top it off, they said that they were giving me a new gascap as a goodwill gesture. Turns out though that in a conversation a week later with another dealer service manager he said that over 90% of their CEL were because of faulty gascaps. See why I don't trust the CEL.

Jack

Jack I'm not surprised that it may be that your gas cap is the whole problem. Sometimes solutions, to what some call major problems, are simple things. Topping off your tank can cause a fault code to appear and a shop or dealer will want to test the entire system at your expense. The solution-clear the code and stop topping off the tank.

Interesting thread. I have had my CEL coming on for years due to 2 P codes resulting from headers on my 2000S. I turn off the CEL using the duramteric software from time to time. I have also in the past reset the light by unplugging all the fancily connected cables from the ECU for a few minutes and then reconnecting them. Also, if the battery goes dead, the CEL resets.

Twere my car, I would first determine what the codes were and then come to the boards for insight. If nothing alarming, reset the light one way or another and see if/when it comes back.

I think there are a lot of misconceptions about CEL and the resulting codes that scanners turn up. Current OBD II/CAN systems can be an absolute God-sent benefit to someone that understands that a code is not necessarily an absolute answer to a problem, but the start of a route to finding it. When you plug in the computer, you should not turn off your brain; but unfortunately, shops that were “parts replacers” before OBD II still are doing the same thing.

When your DME trips a code (or codes), you have to take them into perspective with the engine’s systems and do some mental diagnostics of your own. An O2 sensor throwing an “out of range high or low” does not necessarily mean that the sensor itself is bad; it is reading out of range. The questions should then be “Why?” Unfortunately, far too many dealers and independents’ immediately start changing parts before they engage their brains. The O2 sensors have both voltage and resistance range specifications that can be easily verified while still in the car. If the unit is in spec, it is not the issue; the problem lies elsewhere in the system. If either the voltage or resistance is out of spec, the sensor is bad and need to be replaced before proceeding.

Unfortunately, we live in an age where mediocre diagnostic skills have become the norm in the face of ever more complex engine technologies. An individual has his CEL go on, goes to the dealer and is told it is an O2 sensor code, and he needs four new sensors. Several hundred dollars later, shortly after getting the car back, it throws the same code. He brings it to my shop, where we scan it and then put it up in the air for a quick visual inspection, during which we find a small oil leak on the passenger’s side. Looking more closely, we see the dipstick tube is cracked. We replace the tube, clear the code, and (to date, some 9 months later) it has not come back on. My opinion is that the car never needed the sensors; it was an air leak in the dipstick tube.

Regardless of if you do your own work or take the car to someone, you are forced to know more than they do to make sure you are not getting taken for a ride.

A comment to the poster who has had a CEL on since installing headers: I am willing to bet that your headers do not have a built in cat, or use only one set of O2 sensors (no bung in the header). Because only the US cars use four sensors (the DME is looking at the differential between the pre and post cat sensors), if you took the car to an independent with a PST II, or a friendly dealer with a PIWIS and had them reprogram the DME to RoW (rest of the world) emissions standards, your CEL will go out and never return. And the car will pass emissions testing in all 50 states………………

Fair use allows me to snip the fault areas out of the DME manuals
but not enter all the diagnostic steps that are suggested the mechanic go through and in what order. As JFP has posted in this thread, there is no substitute for competence and reading the book and not just reacting to a 4 word code explanation and throwing parts at the problem. The latter is the fastest way sometimes and so benefits the mechanic who is on a flat-rate compensation scheme. But I find a mechanic who doesn't work that way and I watch him from a distance (or even, if he allows, get in there and think with him). I expect that the diagnosis is part of the flat rate and we'll get it right the first time. Oh we may get it wrong the first time every once in a while but it better not be a common thing or I go find another mechanic.

And I scan the code myself and do research before I go in. If it is a lazy O2 sensor, I figure that is either something I can do myself or any exhaust shop can do for less than a shop that invests in a PST2/PWIS..and with OEM parts that cost half. For some other faults, I need someone with specific M96 expertise and I expect to pay for that and to get the commensurate results.

I don't mind buying tools...every job is an excuse. And a code reader is my friend when I am 40 miles from the nearest mechanic. Heck, I read the codes before I go get a smog check. And I've even discovered where Honda hides the OBD II port so the reader saved me $400 when my CRV needed a sensor.

I figure it helps when I go in to my mechanic and schedule a visit that I give him the specific code and let him go from there...he knows I'm watching and it saves me from being perceived as a deep-pockets. Just like I go into buy tires having done my homework and gotten prices and reviews so I can ask for the best deal knowing what it should be.

I figure my code reader has saved me about 3 times its cost by now.

Actron 9135 is what I use. Not the best, but good enough considering I don't have a laptop and and am not going to the level the Durametric SW would go anyway. I leave that for the experienced mechanic and his special tools.

I'm posting the outcome of the third smoke test done on my car to determine the reason my CEL came on. It was found that a $15 rubber hose part, that is a part of the air/oil separator system had a small hole in it that was causing a vacuum leak in the system. The part was cut off so it is in three sections but the picture will give you an idea of what it looks like and its size. I hope this helps someone else who has the same codes and a CEL locate the problem. It was a $266 repair for the analysis, part and installation. I still have the secondary air intake to deal with but my car doesn't need smog until July so I'll deal with it then but at least the fuel mixture is no longer leaned out and the car is running great.

Mike, Where does Honda hides the OBD II port on a CRV?

Quick update. I took the car to a mechanic who connected his device to the interface under the dash. The reading was P0455, a "gross leak detected in the Evaporative Emissions System". This was the same code it gave the first time around when this whole thing started. He then reset the computer and upon starting the car the "Engine Check" image did not lite. I have driven the car about thirty miles since making several stops on the way home and still no lite. The mechanic cautioned me that sometimes it takes some time for the leak to build up and that I should wait awhile before I jump for joy. Based on my original feeling that I was jobbed by the dealer I will be cautiously optimistic and report back after additional usage..

Jack

Well I'v also got a further story to add to all of this. The shop that changed out my rubber air/oil separator bellows told me that to get rid of the remaining codes and turn off the CEL for good I needed to replace the all the valves and vacuum tank in the secondary air system at the tune of almost $700. I took the car to Alden at Flintworks and he found the problem in less than 20 minutes it was a 25 cent vacuum hose that had broken in two at the valve under the intake manifold. Needless to say his bill was far less than the other shops. No wonder Porsches have the rep of being high maintenance cars if repair facilities are telling customers they need to replace entire systems instead of just faulty parts.

2nd update. Drove another 100+ miles today with numerous stops for food, groceries, etc. Still no engine check lite.

Jack

jborchel said:

2nd update. Drove another 100+ miles today with numerous stops for food, groceries, etc. Still no engine check lite.

Jack

Click to expand...

Jack at some point you will want to re check your OBDII readout to see if those fault codes are being stored.

There is a big difference between a good and honest mechanic and a shop that just changes parts. Has nothing to do with Porsche though the parts exchange place does find it easier to get away with their tactics when working on a more expensive car (especially if the owner hasn't a clue and just threw $ at the purchase).

Learn who is good and who you can trust and treat them more than right. (says he who just bought his 3rd car worth of tires at the same shop in 6 months).

offshore said:

Jack at some point you will want to re check your OBDII readout to see if those fault codes are being stored.

Click to expand...

Offshore,

Thanks for your advice. Could you explain the your statement above? What impact does the storage or non-storage of the codes have?

Jack

jborchel said:

Offshore,

Thanks for your advice. Could you explain the your statement above? What impact does the storage or non-storage of the codes have?

Jack

Click to expand...

From what I can figure it depends on the codes and the number of cycles they appear. When I first bought my car airbag, seatbelt, and O2 sensor fault codes appeared but had not triggered a CEL, were erased and didn't appear again until I had the seat taken out for some work to be done on the console and the OBDII reader was hooked up and all the codes appeared again but had not triggered a CEL. All the codes were erased and when the recent emission fault codes appeared again with a CEL, the airbag and seatbelt codes were absent. If you can pick up a Bentlley Manual and on page 24-25 it explains the sequence of tests the the computer runs and how fault codes are registered and trigger a CEL.

A-a-r-r-G-G-H!! It's back. On the way home from a party a couple of weeks ago the CEL came on again. The car had about 25K miles on it when this happened. The original dealer repair bill shows 24,428 miles when the repair was first done. This was late September and it's now early May. You can see the Boxster isn't driven very much.

I've been trying to look for a pattern to this and the only things I have come up with are:

1. On the 1st and 3rd occurrence the gas tank was near empty.
2. Around the time of the 1st and 2nd occurrence I had messed with the little locking plunger at the gas cap area.

Do any of these things light a bulb with anyone?

I'm going to buy an Actron CP9135 and reset the system again and see what happens. After reading all of the posts above I can see that the real and proper fix is probably one that is executed by a knowlegable mechanic. I wouldn't mind paying for the right repair. This problem really puts a damper on owning this fine car.

Jack