Strange TPS reading with 12P

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Charlescrown
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Strange TPS reading with 12P

Post by Charlescrown »

I don't know if this is peculiar with 12P or it would shown on any log.
When observing the TPS voltage and percentage the voltage climbed to a max of just under 5 volts with the throttle percent climbing to 99%. Yes this I know is correct but there was a little more throttle left and when pushed the extra bit the voltage stayed at almost 5 volts and the throttle percentage dropped to 2%. It even showed on the monitor to drop down to zero percent. I adjusted the TPS to prevent it happening and it now shows the full voltage at 99% and does not drop. Can anyone explain to me whats happening?
I would think a 2% reading at WOT would confuse the hell out of the program.
slewinson
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Re: Strange TPS reading with 12P

Post by slewinson »

I saw another post on this but cannot locate it. Basically, the ECU 5V out line is slightly higher than what it seems "full throttle" and if the TPS over travels it wraps around and sees no throttle opening. I recall that adjustment of the TPS was required. Antus or The1 enlightened us if my memory is accurate.

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VL400
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Re: Strange TPS reading with 12P

Post by VL400 »

This thread has the same issue .. http://pcmhacking.net/forums/viewtopic. ... tps#p53984

You need to set the WOT voltage to something lower than 5V or the code does behave a little odd. That part of the code is factory $12 so maybe something has been missed and it rolls over in the calc, although its a situation that shouldnt happen due to fault checking and how the TPS should be setup (still not good practice).


Also code 21 for High TPS A/D is 246 counts. This is 246/255 * 5 = 4.8V.

So, anything above 4.8V for over the "TPS High Time Limit" item (default 2 seconds) will set a code 21 and then use the default TPS table.
Charlescrown
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Re: Strange TPS reading with 12P

Post by Charlescrown »

Thanks VL400 that's exactly what happens. It did register the code for high TPS voltage. Thanks for the info.
slewinson
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Re: Strange TPS reading with 12P

Post by slewinson »

Thanks VL400. That was the thread I remembered.

Simon
Charlescrown
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Re: Strange TPS reading with 12P

Post by Charlescrown »

All fixed I adjusted the TPS so it reads 99% at WOT. Chasing another issue now the o2 sensor works intermittently. Not struck that problem before.
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Re: Strange TPS reading with 12P

Post by jca »

Hi guys im having a tps voltage/% problem reading this thread it looks like i can adjust the full throttle voltage in 12p but can i also adjust the low voltage when the throttle is closed its on a comversion its currently tuned with kalmaker but it looks like they are runing a 2 bar map sensor with a 1 bar tune looking at the map sensor readings which i think can cause tps
problems ive mucked around with the mounting of the tps but its like the tb shaft doesnt rotate in the same proportions as the tps switch it also has a maf installed its on a hyundai 4 cylinder turbo
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