Throttle Position Sensor ( TPS )
#1
Throttle Position Sensor ( TPS )
i m suspicious about my TPS cuz ECU isnt throwing any codes and resistance on TPS is wrong....according to FSM if throttle valve is completely released there should be around 1 ohm and if completely depressed there should be around 9 ohms....but my thing is totally different...wen throttle valve is completely released i have around 9 ohms and if completely depressed i have around 2 ohms and ya one more thing wen i go up to 4000rpm my car cuts off like it jus wanna stop and dont wanna go that high....it means my TPS is gone? thanks
#2
i m suspicious about my TPS cuz ECU isnt throwing any codes and resistance on TPS is wrong....according to FSM if throttle valve is completely released there should be around 1 ohm and if completely depressed there should be around 9 ohms....but my thing is totally different...wen throttle valve is completely released i have around 9 ohms and if completely depressed i have around 2 ohms and ya one more thing wen i go up to 4000rpm my car cuts off like it jus wanna stop and dont wanna go that high....it means my TPS is gone? thanks
Last edited by Max_5gen; 09-27-2008 at 11:18 PM.
#3
What is important for TPS is 'smootheness' of its resistance throughout its range. It should't brake the contact at any angle. Another important thing is the adjustment of the 'closed' throttle position. TPS has 2 more group of contacts: one is responsible for that zero point detection and another - for WOT. The second one is not used at all. I found the best way to adjust TPS is to hook up multimeter and measure resistance of the zero point contacts. You turn TPS with closed throttle to the position that the minimal touch to throttle opens that zero position sensor contacts. Automatic cars are very picky about this adjustment - if you mess it up it starts to slam into gears so hard that my wheels were slipping. I wouldn't believe that TPS could cause this if I didn't see it myself.
#4
so this is a way u r saying to adjust TPS....connect multimeter to TPS sensor then move closed throttle position sensor with ignition on till i get around 1 ohm on multimeter? correct me if i m wrong....
#5
You most likely only need to adjust it using the procedure I described. BTW, FSM is wrong - it recommends adjusting TPS based on its main sensor output voltage. I tried and couldn't get it out of my TPS for the life of me. Then I thought: "How would ECU know the zero point? There's even sensor for that ...". It worked from the first try. It seems ECU doesn't really care about absolute voltage much, it just needs correct zero point.
#6
You need TPS installed on TB. Then you have to disconnect connector of the closed throttle position sensor (CTPS). Connect your multimeter to CTPS and turn TPS around until you set it so that slight opening of the throttle opens the CTPS contacts.
#8
#9
just to make sure...u connect ur multimeter with the throttle position sensor then move the closed throttle position sensor and then where i get around 1ohm ( zero point ) i stopped there and tight the sensor screws..?
#10
TPS has 2 connectors - one for TPS itself and another - as FSM calls it 'Hard closed throttle position switch'. You need to connect multimeter to that switch connector. TPS connector can be connected into harness as usual, it is not even needed for adjustment.
#12
This could be something else, I was talking about gear changes 1->2 and 2->3.
#13
The Transmission controller (TCU), uses the TPS to determine engine load, as you can imagine, with a wide open throttle, the transmission shifts at much higher RPM and also runs a higher line pressure to ensure there is minimal slip, at a small throttle opening, it shifts at lower RPM and runs a lower line pressure to ensure smooth changes. The TPS is the only sensor it uses for this. If the TPS is not adjusted correctly it will either shift too early and slip, or shift at high RPM and have harder shifts.
If your transmission appears to be shifting at the right RPM, but changes are very hard, I would suggest your TPS is not the cause, but the dropping resistor or a faulty line pressure solenoid in the transmission.
Either way, the TPS adjustment should be checked, as it is a fairly easy task.
If your transmission appears to be shifting at the right RPM, but changes are very hard, I would suggest your TPS is not the cause, but the dropping resistor or a faulty line pressure solenoid in the transmission.
Either way, the TPS adjustment should be checked, as it is a fairly easy task.
#14
The Transmission controller (TCU), uses the TPS to determine engine load, as you can imagine, with a wide open throttle, the transmission shifts at much higher RPM and also runs a higher line pressure to ensure there is minimal slip, at a small throttle opening, it shifts at lower RPM and runs a lower line pressure to ensure smooth changes. The TPS is the only sensor it uses for this. If the TPS is not adjusted correctly it will either shift too early and slip, or shift at high RPM and have harder shifts.
If your transmission appears to be shifting at the right RPM, but changes are very hard, I would suggest your TPS is not the cause, but the dropping resistor or a faulty line pressure solenoid in the transmission.
Either way, the TPS adjustment should be checked, as it is a fairly easy task.
If your transmission appears to be shifting at the right RPM, but changes are very hard, I would suggest your TPS is not the cause, but the dropping resistor or a faulty line pressure solenoid in the transmission.
Either way, the TPS adjustment should be checked, as it is a fairly easy task.
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