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Question How can I tell if the throttle position sensor has failed? (Posted by: Anonymous )

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Answer
The throttle position sensor, TPS for short, is a sensor that is used in an internal combustion engine. These can be fuel injected engines or carbureted engines. The TPS is used to monitor the position of the throttle butterfly valve.

When we accelerate, the butterfly opens a little or a lot to allow air into the intake manifold, depending on how much you are accelerating. There are a few signs that could be a signal that the throttle position sensor is failing. The first and foremost is a possibility that your check engine light could come on; this is a light on the dash that sometimes appears as a little engine or sometimes it simply says check engine.

Next scenario is that the car idles rough, this is when the vehicle is in a stationary position and you get a rough feeling from the engine almost as if the vehicle wants to stall out. Finally you may find that the vehicle hesitates on acceleration. To make a proper diagnosis we first need to get our tools in order.

The main and only item in the tool list is what is called an ohm volt meter. Once you have identified the TPS sensor, turn on the ignition, do not start the car, make sure the volt meter is on twelve volts DC. Locate the connector that goes from the ECM (engine control module) to the TPS. Once you find this disconnect it completely from the throttle position sensor. There are three prongs; the center prong is usually the negative connector.

Once this is done, take the volt meter and connect the negative side (usually the black wire) to the ground terminal on the battery. When this is done take the positive lead, (usually the red wire) and attach it to one of the other prongs. The volt meter should read five volts, if you are on the reference wire for the TPS. If it reads anything below five volts then you are on the signal wire and need to go to the other prong in the connector. If it reads nothing on the volt meter then you are on the negative connector. Once you locate the reference wire, and it reads five volts then you know that you are getting proper reference voltage to the TPS. Therefore you have just eliminated a faulty power feed to ECM.

The next step is to put connector back on the Throttle Position Sensor. Take the positive lead for the volt meter and put it to the signal wire in the back of the connector, this is known as back probing. Take the negative lead from the volt meter and put it to the center wire which is negative on the connector, take the butterfly shaft and turn it gradually and as you turn it you should get a gradual count upwards to five volts. If the volts fluctuate backwards or forwards then you know you have a faulty throttle position sensor.

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My car would not accelerate when it is warm (after driving 5-8 miles) Does not misfire or run rough. When in park position it revs excellent. I was told that it is the TPS, any help. Thank you. By Saad on 23-01-13 at 11:36pm
you could possibly give a correct setting on the sensor as to how much the throttle needs to be open at idle as there is an adjustment on the sensor which allows you to move it By ron on 06-02-13 at 06:36pm
when my car is in park the engines sound like it is racing an when i accelerate it slow down before it pick up speed even when i am at a stop light an to move it take a while before it pick up speed.i am told it need throttle body. By nola on 04-03-13 at 03:33pm
where is the tps located on a ford escort By Neil on 29-03-13 at 12:11pm
Thanks for the answer. It described what my car was doing. I had to get a TPS. The part cost $89.00. I was charged $95.00 for labor plus $6.00 tax (total bill $190.00) By Tasha on 18-04-13 at 06:14am
THANK YOU. NOW I KNOW IT IS MY TPS. I HAVE ALL THOSE PROBLEMS LISTED ABOVE. IT WILL COST ME
80.00 TO FIX. THANKS AGAIN By EUTOYE on 11-06-13 at 03:51pm
This was a very specific and well written answer By Doug on 12-07-13 at 12:35pm
As you have detailed in your answer, the problems i am experiencing is exactly what you have mentioned. Shaking of the car when idle or idlying rough; sluggish/delay in acceleration when ready to drive or when i have stopped at a traffic light and i am ready to drive off the sluggishness occurs. i will follow your instructions to accurately determine if it is the TPS. Thanks for this. Really infromative. By Nigel on 11-08-13 at 03:02pm
Thought I would share my experience. Several years ago my car's RPMs would suddenly shoot up and I had difficulty slowing the car down and coming to a stop, very scary. After several failures by the dealership to solve the problem, they finally contacted their tech support who knew right away to replace the TPS. No problems since. By Susie on 16-08-13 at 05:38pm
my Renault laguna ,the ACCELARATOR PEDAL does not work at all.it idle but when i press the pedal nothin happens . By ROBERT on 19-09-13 at 06:19am
how long does it take to replace throttle position sensor? By Deise on 14-10-13 at 10:10am
That one person says $95 labor, that is ridiculous, it's 5 minutes work. Glad I don't go to mechanics. By Anonymous on 14-10-13 at 11:16am
My chariot car is behaving in the same way as explained above. Let me give it a try and see what happens! Thanks for the answer! By Moses on 06-11-13 at 01:26am
This was an excellent bit of advice for me. I was getting a TPS code so I replaced the TPS. It still didn't work but my problem became consistent where it was intermittent. By measuring the signal from the TPS I was able to learn that the linkage hadn't connected properly. Re installing the TPS and verifying the signal changed with the throttle provided the sanity check I needed to make sure the part was installed correctly which ultimately resulted in getting the problem fixed. In my case, the transmission would not shift down under high acceleration. By John on 15-11-13 at 04:36pm
The symptoms spoken about in this article are describing what's going wrong with my Pick-Up Truck. The explanation was precise and easy to understand to me. Thanks a lot. By Edgar on 24-11-13 at 11:46pm
when i test my TPS with the gas plate closed, the reading is 5v. when slowly opening the gas plate, the voltage is decreasing. what those that means please. help By Ibrahim on 19-12-13 at 04:05am
As an alternative to the multimeter, use an OBD
-to-laptop/mobile interface (commonly the ELM3
7) on 1996 and later vehicles. With key on engine off, set up up the laptop or phone to monitor the ECU TPS data, then gradually depress the gas pedal to monitor the TPS via ECU; you should get stable/clean readings, without unexplained fluctuations. By Peri on 27-12-13 at 01:04pm
Changed accelerator position sensor, now engine runs but won't accelererate. Dodge 3500 cummins 5.9 engine By Dennis Brown on 17-02-14 at 10:12pm
my chevy impala is doing all thing you have up on here ok but there no codes saying thers something worng my car hesitate and when I get up to 30 or 60km it slugging and wont get up to it passing speed did sark plugs wire s fule felter to can you halp me befor I go get the tsp sensor see if it works thank By Chester Baylis on 21-03-14 at 09:58am
It would be a complete waste of money to get a mechanic to do it. I am not mechaniclly inclined at all an it took me all of 5 minutes to change this sensor. Truck runs way better now By Anonymous on 04-04-14 at 04:21pm
Is the throttle sensor part of the engine system? By Anonymous on 19-04-14 at 04:32pm
my mechanic changed the TPS and now the car is still acting like it wants to die. I have a 1995 Infiniti G
0 standard By martha on 20-04-14 at 06:57pm
My car needs to have the main drive pulley taken off to change the TPS and you need a special tool from GM to do that so piss off to the people who says it's easy.
000 Pontiac Grand Prix. By Nick on 23-04-14 at 11:17am
I am experiencing these symptoms as well on my 1990 Ranger
.3l. Read my voltage with a voltage meter and foynd that my TPS was only reading 3.1
volts. Went to STAR Auto and biught my TPS for $
3.99 and put it in. Now my ranger idles and drives amazing. I had rough idle issues and rapid idle increases and decreases so if anyone is experiencing issues w/ idling etc than it is most likely yohr TPS. By Jason on 18-06-14 at 05:36pm
Mu isuzu dmax 3000 model
005 having engine always shut off with out reason.any body know or have semilar problem .help pls By lukas hong on 20-08-14 at 11:45pm
I am having a problem my
004 Nissan Murano,when I accelerate to 40 on my speedometer the gears does not change and I will hear a sound of higher acceleration. I was told my throttle could be faulty. Can someone please help me out? By cosmos on 07-09-14 at 10:05am
Hey I am experiencing this problem myself My 1997 Ford F-150 4.6 liter V8 is having a bad rough idle in park without taking it out of park into reverse and drive, then it will idle smooth, I am not liking that, I got am new throttle position sensor after reading these reviews about the same problem related to mines, I got to install it and reveal the results, and hopefully I will feel relieved, I done had that problem for quite some tome. I am surprised that it has not prevented it from cranking up period, just do not like to feel that bad rough, shaky, vibration when cranking up my ride. By Brad on 03-10-14 at 12:00am
I have a 93 k5 blazer with the 5.7 350 when its in park it idles around 900ish IN PARK when I put it in gear it goes to about 400ish and when i floor it it kind of bogs down and then picks up back but not with the "humph" a 350 should have any suggestions ? By Anonymous on 26-10-14 at 10:57pm
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