Nosedive on shift fixed; peeved w/Autotap
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From: Live Oak, FL - in the woods where the creatures lurk.
Nosedive on shift fixed; peeved w/Autotap Background: after ST3500 install had weird 1-2-1-2 shift pattern @ WOT. Finally cured by going +4 on 1-2 shift w/HPP3.
BUT shortly thereafter I seemed to get TM way worse than ever.
After many, many Autotap runs monitoring at most 4 parameters I finally caught the true culprit: It was hitting the rev limiter. DUH.
Autotap would usually catch the pulled timing and fuel, but finally today I caught it going over 6200 rpm (6238). Very disappointing.
For now I've got the limit raised to 6300 as lower shift settings (< +4) give that funky 1-2-1-2 shift.
BUT shortly thereafter I seemed to get TM way worse than ever.
After many, many Autotap runs monitoring at most 4 parameters I finally caught the true culprit: It was hitting the rev limiter. DUH.
Autotap would usually catch the pulled timing and fuel, but finally today I caught it going over 6200 rpm (6238). Very disappointing.
For now I've got the limit raised to 6300 as lower shift settings (< +4) give that funky 1-2-1-2 shift.
Re: Nosedive on shift fixed; peeved w/Autotap When I test my shift points, I only ATAp speed & rpm; sometimes just rpm. Otherwise there is too big a time gap between readings.
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From: Murphy, TX
Re: Nosedive on shift fixed; peeved w/Autotap SAE J1979 specifies that the minimum time between requests from a scan tool is 100 ms for SAE J1850 network interfaces. Not sure if the ISO interfaces are any better (although that doesn't really matter.) AutoTap looks to be doing what it can.
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From: Live Oak, FL - in the woods where the creatures lurk.
Re: Nosedive on shift fixed; peeved w/Autotap </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ToplessTexan:
<strong>SAE J1979 specifies that the minimum time between requests from a scan tool is 100 ms for SAE J1850 network interfaces. Not sure if the ISO interfaces are any better (although that doesn't really matter.) AutoTap looks to be doing what it can.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Okay. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I'm sure it's doing what it can, but what it can do took ~15 runs to catch the one parameter I needed most. Sigh. Still a good tool, though.
<strong>SAE J1979 specifies that the minimum time between requests from a scan tool is 100 ms for SAE J1850 network interfaces. Not sure if the ISO interfaces are any better (although that doesn't really matter.) AutoTap looks to be doing what it can.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Okay. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I'm sure it's doing what it can, but what it can do took ~15 runs to catch the one parameter I needed most. Sigh. Still a good tool, though.
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Re: Nosedive on shift fixed; peeved w/Autotap Sorry do not agree.
Autotap is a lousy design and is not requesting more concurrent functions per request thus it is not the time between requests it is how much you ask for in each request.
Ease scanner when fast data packets is turned on asks for 8 times more then autotap per each request and reason it is approved for EPA I/M testing and autotap is not.
<small>[ June 15, 2002, 05:32 PM: Message edited by: Team ZR-1 ]</small>
Autotap is a lousy design and is not requesting more concurrent functions per request thus it is not the time between requests it is how much you ask for in each request.
Ease scanner when fast data packets is turned on asks for 8 times more then autotap per each request and reason it is approved for EPA I/M testing and autotap is not.
<small>[ June 15, 2002, 05:32 PM: Message edited by: Team ZR-1 ]</small>
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From: Murphy, TX
Re: Nosedive on shift fixed; peeved w/Autotap I hear ya. It's a pain to catch short duration events. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
Just pointing out that it won't be any better with any other OBD-II scan tool.
Just pointing out that it won't be any better with any other OBD-II scan tool.
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From: Murphy, TX
Re: Nosedive on shift fixed; peeved w/Autotap I can agree that AutoTap is crap. I can't agree that a lack of so called "fast data packets" is the reason it's not J1978 compliant. The lack of near and dear to your heart readiness test support is a much larger failing. The J1979 spec is attempting to limit bandwidth utilization by any compliant scan tool. That EASE may do a little better wrt sampling rate limitations (which is a good thing) does not mean that it offers an arbitrarily fast sampling rate.
<small>[ June 16, 2002, 11:13 AM: Message edited by: ToplessTexan ]</small>
<small>[ June 16, 2002, 11:13 AM: Message edited by: ToplessTexan ]</small>
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From: Milford, Ohio
Re: Nosedive on shift fixed; peeved w/Autotap I don't know all the details, but the SAE protocol standard is not particularly efficient in it's most basic form. However, the data packets can be structured for much more efficient data retrieval. I have been using EFILive and am impressed with it's speed compared to AutoTap. My general drive log to monitor fuel trims, etc. logs 19 parameters (using all 24 channels) and updates in less than 200ms on average - that's roughly 100/120 parameters/channels per second.
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From: USA
Re: Nosedive on shift fixed; peeved w/Autotap I agree the SAE protocol is slow but do not forget the PCM CPU is less then 17 Mhz and connection from ADLC is less then 15K baud and all exchanges with a OBD-II scanner is not raw data but has to be encased in a packet, thus forcing PCM CPU to take more of its clock time to add the protocol to each scanner request slows everything dependent to the PCM buss.
The more concurrent functions the scanner is requesting the more PCM overhead including to the PCM buss.
In the case of a C5 Corvette it gets worse since it has more body and chassie modules that exchange info across the PCM. With my Ease scanner is I can request the position of the seats or even a outside mirror, thus there is a lot of overhead.
Interesting the user can use a 1 GHz laptop but the PCM's CPU is many times slower.
My point is yes a procotol slows the process down and adds cpu load to PCM but in the case of Autotap their design stinks and reason it cannot maintain a link to PCM much less request for info with the timing of SAE timing.
Ask yourself why autotap does not record DTCs during a recording, reason if they allowed the DTC requests they would be even slower.
So if a scanner like Ease can request 160 functions a second and request DTCs then so should any other OBD-II scanner if they are complying with the requirements of the protocol and timing windows.
The more concurrent functions the scanner is requesting the more PCM overhead including to the PCM buss.
In the case of a C5 Corvette it gets worse since it has more body and chassie modules that exchange info across the PCM. With my Ease scanner is I can request the position of the seats or even a outside mirror, thus there is a lot of overhead.
Interesting the user can use a 1 GHz laptop but the PCM's CPU is many times slower.
My point is yes a procotol slows the process down and adds cpu load to PCM but in the case of Autotap their design stinks and reason it cannot maintain a link to PCM much less request for info with the timing of SAE timing.
Ask yourself why autotap does not record DTCs during a recording, reason if they allowed the DTC requests they would be even slower.
So if a scanner like Ease can request 160 functions a second and request DTCs then so should any other OBD-II scanner if they are complying with the requirements of the protocol and timing windows.