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My company provides the service of setting Porsche 993 monitors for smog tests for 993 owners or Porsche repair shops
here in SoCal. Typically, it takes about 45 minutes to set all the monitors in a single test drive!
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Loren
Systems Consulting - Automotive Electronics
Specializing in Porsche cars http://www.systemsc.com/
Really? Using any Porsche tester you can! If you have one, consider learning how to use it. Did you not see this or understand it from my website?
Notes: The above cycle flags when completed (set) comprise one trip. After completion of the
1st trip, the engine is stopped (cycle flags reset) & restarted to begin the 2nd trip, followed by
a 3rd trip if necessary. A cold engine is required between trips for the SAI test if not using the
Short Test (Porsche diagnostic tool). If the engine is stopped, e.g. stalled, before completion
of the trip, the trip must be restarted from the beginning & all completed cycle flags are reset
for that trip. Once all the necessary trips have been completed, the readiness codes will be
indicated by an OBDII scanner. The exception to this is the '98 993, where only one trip is
required over numerous days, and the readiness codes appear as they complete using a generic
OBDII scanner. For the pre-'98 993s setting of the readiness codes is extremely difficult without
the use of a Porsche diagnostic tool, e.g. Hammer, PST2, or PIWIS.
how does the Porsche diagnostic tool bypass the need for a cold start?
how does the Porsche diagnostic tool bypass the need for a cold start?
The Porsche tester software when communicating with 993 DME ECM is able to enter modes which a simple OBDII scanner can't.
The modes "force" the ECM to run the secondary air test and the EVAP test directly irrespective of the engine temp.
During the secondary air test the tester provides the O2 sensor voltages, which allows one to determine if the air injection
ports are problematic. The Porsche tester software is proprietary and is NOT part of any standardized OBDII diagnostics.
I did the drive cycle few times in the past week and was unable to reset all the codes. I was able to do it in one drive two years ago so it made me scratch my head and wondering what had changed....I finally realized I had oil cooler fan modification cable put in last year: https://rennlist.com/forums/993-foru...ification.html
I thought I would just give it another try. I took the cable out earlier today and then went for a drive. I plugged in the OBD reader after about 20 mins drive and all codes now show "Passed"!
Went straight to smog check station and had my smog passed! I am good for another two years!!
Want to thank all the helpful info in this thread, especially Loren (Systemsc) who gave me different suggestions for the drive to reset the codes. So just a note, if you have the 993 oil cooler fan modification cable installed, remove it before doing the drive cycle!! Hope this helps other!
As another data point for a NB NA '96 6-Speed, by strictly following the BMW drive cycle from cold, I've always reset the codes on the first try, and takes about 30 minutes.
I did the drive cycle few times in the past week and was unable to reset all the codes. I was able to do it in one drive two years ago so it made me scratch my head and wondering what had changed....I finally realized I had oil cooler fan modification cable put in last year: https://rennlist.com/forums/993-foru...ification.html
I thought I would just give it another try. I took the cable out earlier today and then went for a drive. I plugged in the OBD reader after about 20 mins drive and all codes now show "Passed"!
Went straight to smog check station and had my smog passed! I am good for another two years!!
Want to thank all the helpful info in this thread, especially Loren (Systemsc) who gave me different suggestions for the drive to reset the codes. So just a note, if you have the 993 oil cooler fan modification cable installed, remove it before doing the drive cycle!! Hope this helps other!
Andy
Congrats. My 993 is being serviced. As soon as it's back i'm going straight to a STAR station.
As another data point for a NB NA '96 6-Speed, by strictly following the BMW drive cycle from cold, I've always reset the codes on the first try, and takes about 30 minutes.
That's great! Sounds like you have '98 DME ECM installed versus a '96 DME ECM, i.e. you don't need multiple trips with a cold starts between trips as required by all '96 993s.
Is it bad form to say I have a '95 OBD-1 car and I thank my lucky stars for this? Sweet Jesus, what a complicated process. I sweat passing that stupid test under normal conditions, let alone adding this complicated OBD-2 crap. Hats off you all, especially in California. I've been barely passing my 1995, 150k miles 993. Nightmare.
Is it bad form to say I have a '95 OBD-1 car and I thank my lucky stars for this? Sweet Jesus, what a complicated process. I sweat passing that stupid test under normal conditions, let alone adding this complicated OBD-2 crap. Hats off you all, especially in California. I've been barely passing my 1995, 150k miles 993. Nightmare.
It's really not that bad and only applies if you've pulled the battery for some reason. If I can reset it on the first full attempt, anyone can do it.
This thread makes it seem much more difficult than it really is. On most of these cars, Californian no longer tests. I'm in Colorado and still require smog testing every 2 years. However, they don't connect to the car to check readiness monitors any longer. Just what comes out of the tailpipe.
I'd much rather have to do the drive cycle every time I change the battery instead of living without varioram. The added troubleshooting functionality of an OBD 2 compliant system is nice as well.
Last edited by 71-3.0-911; 09-20-2023 at 01:36 PM.
It's really not that bad and only applies if you've pulled the battery for some reason. If I can reset it on the first full attempt, anyone can do it.
This thread makes it seem much more difficult than it really is. On most of these cars, Californian no longer tests. I'm in Colorado and still require smog testing every 2 years. However, they don't connect to the car to check readiness monitors any longer. Just what comes out of the tailpipe.
I'd much rather have to do the drive cycle every time I change the battery instead of living without varioram. The added troubleshooting functionality of an OBD 2 compliant system is nice as well.
Not really! If you own a pre-'98 993 it's difficult, i.e not knowing when you've completed each trip of a minimum of two.
Read here under Porsche 993 Cycle Flag Basics; https://www.systemsc.com/codes.htm
I have a 96. I completed the BMW drive cycles exactly as listed at like 3AM. Took me 2 trips from cold and on the third start, all green. Really not a lot of mystery there.
It's really not a big deal especially after you have owned the car for a decade or two and you understand the process.
The hardest part about executing the process is understanding the process. Once you understand it, it's easy. It's never taken me more than 3 attempts and 8/10 times it has only taken me 2 attempts. Back in 2002 when I moved to California there wasn't as readily available information as there is today. It took me a few years of referee stations before someone on Rennlist uploaded the OBDII readiness reset instructions.
If you do a search on this subject matter you'll most likely find posts made by me. Of course dealers were always willing to do it for me but at an unspecified cost.
As long as you follow the very easy steps of
- Don't rev about 3000rpm
- Don't exceed 60mph
- Idle for 2'15 from cold start
- 20-30 mph for 3'15"
- 40-60 mph for 15'
- Idle for 5'
Do that on night 1 and then again on night 2 and you should be good to go.
I agree - without guidance from Porsche, the best approach is to find what works for you thru trial and error. What worked for me in my '97 is described here. The commute I was doing at the time allowed me to confirm it worked the same way every time. There are a lot of similarities to B-Line's drive. Mine was specifically designed to get just 3 monitors set (starting from an OBDII reset the night before). This took only 45 minutes. With 3 monitors you can get tested everywhere except CA ,where you 4. With the drive I did, the secondary air monitor didn't go ready until the next cold start, at which point my faulty SAI system invariably tripped the CEL. That was the point. By intentionally testing with the secondary air monitor off, my faulty SAI system went undetected and I passed every time. I'm all done now in CT due to cars older than 25 being exempt. This masking technique will only work for cars able to display monitors one at a time, which typically occurs in '97's and 98's.
09-10-2023, 02:31 AM
