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TPS testing questions/clarification
So im testing my tps, but dont know how to test it exactly on the multimiter. there are settings for 200, 2000 etc. i have the tps off the car already, any chance someone could give me a step by step instruction on testing it, and settings on the multimeter? any help is appreciated.
the cel came on, and that was one of the codes, so i cleaned it with some crc, and want to test it now. any help? |
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Re: TPS testing questions/clarification
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Re: TPS testing questions/clarification
no help, i understood all that. but i know what the numbers mean, so cool. heres what i got.
set at 20 k, with the test leads on middle and bottom(white and red) i got a reading of 5.42 im assuming thats 5420? am i wrong? right? same leads, fully open reading of 0.09. with leads on top and middle, it reads 0.36, fully open at 5.44 what do oyu all think? the sweep across seemed ok, but i dont know for sure. |
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Re: TPS testing questions/clarification
Set your meter to a resistance in ohms scale covering up to 5,000 ohms.
ADJUSTING AND CLEANING THE THROTTLE POSITION SENSOR. In order to adjust the TPS the manual says to measure voltage at the TPS by inserting meter probes into the plug at the ECU plug connection. In order to accomplish the feat at the TPS itself, therefore without tying yourself in a knot under the dash, you will require, best of all one of those dress making pins with a nice thin shank and a knob on the end, or a thin needle. Also a meter to measure 0.5 volts d.c.. The TPS comprises a potentiometer, incorporating a conductive plastic element, presumably used in a voltage divider configuration, as three wires come from it. There is a plug and socket close to the unit so that it can be easily removed for servicing. At this plug the wires are --- black ground and one end of the resistance element, red the other end and white the wiping contact. Holding it with pliers, stick your pin/needle right through the white insulated wire, so that you can clip your meter lead onto it to make measurements. A fine pin will not damage the conductors as they will spread and there will be no significant damage to the insulation. Measure between the wiper, i.e. white wire and ground by connecting to the engine, or battery negative. If you remove the unit, stick the pin in before replacing it, as it is much easier to do on the bench. Don't forget to pull it out when you have done the deed. Now from the book :-- 1. Connect all connectors. 2. loosen TPS fixing screws. 3. Turn ignition on. 4. Adjust TPS position, (i.e. rotate the complete assembly), while throttle valve is confirmed FULLY closed, to specified voltage, using a volt meter. 5. tighten fixing screws. The voltage is specified as within a tolerance of from 0.45 to 0.55 volts. You should have no trouble in setting things at exactly half a volt. Before removing the TPS or altering the original setting it is a good idea to mark the mating castings with a scratch so that one can check on the adjustment, before and after, as a matter of interest. It is always nice to know if the effort expended has in fact improved things. CLEANING AND CHECKING. If the unit is removed, it is easily checked with an ohm meter for smooth operation or otherwise. Evan without dismantling the unit a spray with CRC or similar cleaner and a work out will do wonders. The resistance end to end ( black to red ) should measure very close to 5000 ohms. Measuring between white and red or black should show a smooooooth change in resistance when moving the control shaft over full distance. Blips will indicate trouble. With the unit in place, a voltage check on the output as the mechanism it is operated while connected and energised, will also give an indication of possible intermittent contact. Again using a needle or pin to make a connection can be helpful. A smooth change in voltage should be recorded. A meter with a bar graph will show up short duration faults much better than a normal instrument, digital or analogue, as both have an inherent time delay before indication is registered. This factor should be taken into account but should not deter those without sophisticated gear.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
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Re: TPS testing questions/clarification
my settings let me do 200, 2k, 20k and higher. is 20k good? while im doing the sweet from 5.44 dowm, thewhole and tenths place decimals are pretty smooth, but the hundreths place is jumpy, even when slow, is that normal for me turning itby hand? also, when i have it in the car and set it, do i do it on the ohms setting? or the setting that reads DCV?
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Re: TPS testing questions/clarification
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__________________
Cheers! Gordon 1997 Ebony #308 113k "The Black Diva"SOLD 1992 Black over Liquid Silver 152k SOLD 1992 Ebony 251k 444 SOLD 1999 Silver SLK230 134k SOLD 1997 Green Outback 137k SOLD 2013 Honda Accord I4 SOLD 2015 Subaru Crosstrek 30k 2018 Tesla M3 30k |
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Re: TPS testing questions/clarification
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The measurement should be smooth throughout, up to 5,000 ohms. Not sure what you mean by --- "the hundredths place even when slow". You are looking for poor contact as the moving contact passes a set distance and you must turn the shaft slowly. Read the above data in full so that you understand what is involved. An intermittent contact at the high ohms end of a reading when this is taken from red to black connections, will be of less importance than one at the low ohms end, which will equate with low throttle positions and involves take off and low speed control. Even so any intermittent contact is not a good thing. It is very important that the reading across the complete resistance i.e. from red to black reads a stable approximately 5,000 ohms, no matter how you bump the unit about
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
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Re: TPS testing questions/clarification
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P.S. When setting the TPS use your 2 volt DC range or whatever is closest.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
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Re: TPS testing questions/clarification
thank you agian, youve been alot of help lately!
so ive done the test a few times, and confirmed with my room mate, there are a couple spots where the smooth numberchanges jumps. i guess it may be bad after all. ill find out when i get it back on the car and bolt the driveshaft and exhaust back up. |
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Re: TPS testing questions/clarification
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__________________
Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
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Re: TPS testing questions/clarification
i did that before i tested it. i really wish i would have tested it before i cleaned it to though for a reference on the readings.
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Re: TPS testing questions/clarification
So looking back at this thread, I'm not sure what I'm doing when I try this stuff. I found the TPS, marked it and the throttle body so I could match 'em back up, stuck the needle through the white wire and alligator clamped it to the positive lead on my multimeter, connected the negative lead of my multimeter to my negative battery post. Then I turned the car's ignition to the "on" position.
I had the multimeter set to 20V (since I could register the battery's 12.55 volts in that range, obviously I should be able to register .5 volts). It registered zero. I moved the throttle back and forth and got nothing. So I thought, "okay maybe by 'on' they meant 'cranked'.", so I started the car. Still nothing. So obviously I'm hooking something up wrong. Does the ECU have to be plugged in a certain way? (I ask because many tests on the XT6 require the built in test connectors on the ECU to be either connected or not.) I am trying to test/adjust my TPS because my 4EAT is shifting between 3rd and 4th constantly. Just in case, I removed the TPS and sprayed CRC contact cleaner inside as best I could and worked the spring mechanism back and forth. Not much came out except a barely noticeable few white flakes, which I assume were a bit of corrosion. When I reattached the TPS and took it out for a drive it didn't seem to have made any difference at all. Any tips? Am I hooking it up wrong?
__________________
Austin __________ '97 LSi Ebony - daily driver - mostly just needs body work [couple o' rust holes, door dings, and peeling clear (of course)] '96 LSi, Laguna Blue (retired - soon going to a new home) '89 XT6 5 speed (Gone but not forgotten) |
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Re: TPS testing questions/clarification
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Harvey.
__________________
One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
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Re: TPS testing questions/clarification
What is the "AT"? You don't mean the transmission do you? Like grounding it on the bell housing or something?
---Edit--- Wait a minute - I guess that was maybe a typo? So you mean I just need to connect the negative lead from the multimeter to the TPS - I'm guessing the black wire then?
__________________
Austin __________ '97 LSi Ebony - daily driver - mostly just needs body work [couple o' rust holes, door dings, and peeling clear (of course)] '96 LSi, Laguna Blue (retired - soon going to a new home) '89 XT6 5 speed (Gone but not forgotten) Last edited by Austin; 06-03-2011 at 10:09 AM. Reason: clarification |
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Re: TPS testing questions/clarification
Quote:
Harvey.
__________________
One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
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