Symptoms of a Bad Throttle Position Sensor

[shogun]

The function of the throttle position sensor, aka TPS, is to supply information to the car's computer about the position of the car's throttle. The throttle position sensors contain electro-mechanical moving parts which are prone to wear and tear, which eventually add to the cost of car repairs. Malfunctioning of a TPS can result in improper data being fed to the car's computer, which monitors engine performance, in respect to the fuel efficiency of the car. A damaged, malfunctioning TPS can cause variety of symptoms which are also known as symptoms of a bad throttle position sensor.

Symptoms of a Defective Throttle Position Sensor
Following is a list of symptoms, either of or a combination of which, a car driver may experience because of a defective throttle position sensor:
•Bucking and jerking of the car.
•Idle surging of the car.
•Sudden stalling of the car engine.
•Hesitation while the driver of the car is trying to accelerate.
•Sudden surge in car's speed while driving on the highway.
What Happens with a Bad Throttle Position Sensor?
The data provided by TPS is invaluable for proper startup, idle and easy throttle response of the car. These operations are affected when a bad throttle position sensor feeds erroneous data to the car's computer because of which the:
•Engine Malfunction Indicator Light (MIL) is turned on.
•The driver of a car experiences difficulty while changing gears.
•The fuel economy of the car drops drastically.
•Causes difficulty in setting base-ignition-timing of the car.
How to Test a Throttle Position Sensor?
TPS are manufactured using switch, potentiometer and combination designs. If the TPS is not adjustable then it becomes mandatory that you check throttle stop and throttle cable adjustments. Their improper functioning could cause symptoms such as, poor startup of the car, inefficient response of the throttle of the car, or idle stop. Switch and combination TPS are tested with ohmmeters. In order to test a non-adjustable TPS such as potentiometer TPS, a voltmeter is used and the following list, describes the steps involved in it.
•You need to disconnect the throttle sensor harness.
• Open the throttle valve manually and check the resistance between the terminal 1 and 2 changes.
•Check the resistance in three different positions of the accelerator pedal.
•You may record a resistance of approximately 10-ohms when the accelerator is fully, 2 to 10-ohms partially depressed and 2-ohms when completely released.
It is good idea to go through the manual for specific information which may inform you whether you need to change the TPS or for that matter any of the car's auto parts.

Replacing Throttle Position Sensor
Following are few instructions which can be helpful in replacing throttle position sensor. •Remove the faulty throttle position sensor from the throttle chamber.
•Apply few drops of anti-stick solution to the tip of the replacement throttle sensor and install it in the throttle chamber.
•The anti-stick solution will make it easy for you to remove the TPS in case you need to replace it.
•Start the engine after connecting the throttle sensor harness connectors as specified in the manual.
•Check whether the output voltage of the TPS is within the specified range.
•Tighten the bolts to complete the installation of the TPS.
The longer you take to remedy your car problem because of a bad TPS, the more money you are going to shell out for it. Irrespective of the fact whether you have bought car insurance or not, the first victim of symptoms of a bad throttle position sensor is your wallet, because driving a fuel guzzling car is not cheap for anyone. You will need more gas to travel the same distance and you will be adding more poisonous gases to the environment than necessary.
By Shrinivas Kanade , Last Updated: 10/15/2011

More info here Motronic/DME 1.1 and 1.3 http://forums.bimmerforums.com/forum...ic-1-1-1-3-BMW


please check the details in the Bentley Repair Manual too

[paperplane94]

Thank you
*bows down*


Is it safe to say that if the TPS isn't working the stomp test will not work as well?

[K Fox]

Thank you
*bows down*


Is it safe to say that if the TPS isn't working the stomp test will not work as well?

It will make it harder to get right, yes. Though sometimes you can still get it to go, it just depends on how bad the TPS is.

Fox

[jeremy242]

my car will have throttle surges while drive, the rpm sticks when i take my foot off the gas to coast, when the rpms stick and i stop the car and open the hood and open the throttle body the engine bogs. Does this sound like a tps problem. Some of the symptoms are listed above?

[cdnalpina]

Thanks Shogun!

I suspected my TPS was bad in my B10 3.5, so I bought one and am waiting for it to arrive to install it. Reading your list of symptoms makes me feel even more confident that I have narrowed the problem down correctly.

[jeremy242]

i just check mine and it is reading what it is suppoesed to. The search continues....

Well talked to bmw and they said that even though the ohms are right it may still be bad, and guess what, it was. Replaced it and problems solved for now.

[bimmerbri2]

Good thread started here. I tried stomp test this morning and CEL just keeps flashing and doesn't reveal any codes. Bad TPS?

Sorry for this - total newb on the stomp test. Flashing CEL is the code for faults...I was expecting to see some numbers flash.

[Napkin Fight]

The check engine light should be flashing - no codes will display, the CEL flashes to indicate a number sequence. For example, 3 flashes indicates the number 3.

Re-read the stomp test threads to get more details.

[e34vibes1994]

My 1994 530i does the same thing but it does it constantly from the minute i start my car to actually driving the car it sticks at like 4 to 6k no matter if it is idleing or not really confused on if it might be a bad tps i just bought a new one recently if its sticking could it have something to do with the throttle cable or the throttle body dirty(has been cleaned before) when it did this problem the first time(found out it was a vacuum leak we fixed the problem by capping the leak) or possibly need a new accelerator pedal assembly(i be heard it could be the cause of it too)

[shogun]

Is that the V8 M60B30 engine?
Accelerator pedal can only be broken bushes. That is probably on all our cars in this age. I replaced the bushes some years back. Bushes only cost a few $, see realoem.
Pics from Japan http://alpinakozou.web.fc2.com/file/.../20100103.html

Testing throttle valve potentiometer, copied from the German E34 forum and translated:
Test Drosselklappenpotentiometer M50-Motoren :

Der Poti ist an der rechten Seite der Drosselklappe befestigt und lässt sich nicht einstellen. Die Motronik schickt ein Spannungssignal an das Poti und misst die zurückgegeben Spannung. Die Spannung wird kleiner wenn sich die Drosselklappe öffnet.
the poti is located on the right side of the throttle valve and is not adjustable. The DME sends a signal to the potentiometer and measures the returned voltage. Voltage goes down/smaller when the throttle valve opens.
Test 1 :
- Stecker abziehen/remove plug/connector
- Zündung an/ignition off
- Spannung am Stecker messen. Sollwert 5VDC (ungefähr) / measure the volts at the plug, nominal value approx. 5 VDC

Test 2 :
- Stecker abziehen/remove plug
- Ohmmeter anschließen / connect ohm meter
- Drosselklappe öffnen und Werte messen : / open throttle valve and measure

Pin 1 zu/to Pin 3 : ca. 4.0 KOhm
Pin 1 zu/to Pin 2 : ca. 1.0 bis 4.0 KOhm

Öffnet man jetzt langsam die Drosselklappe dann muss der Wert von 1.0 KOhm nach 4.0 KOhm (jeweils Anschlag zu Anschlag) sich ändern. Ist dies nicht der Fall, Poti tauschen. Poti lässt sich nicht einstellen. / if you open now slowly the throttle valve, then the values should change from 1.0 kOhm to 4 kOhm (from end to end)

[Grindelwald]

I have all these symptos time to order a new one thanks very helpful

[ZUUD BYE]

Thank you Master Shogun!!!

I have experienced these symptoms over the years, new TPS immediately resolved the symptoms.

•Idle surging of the car on the 1995 5251 Automatic

•Hesitation while the driver of the car is trying to accelerate on the 1990 535i Automatic

[Strife]

Sorry for bumping an old thread, by am also trying to determine whether I have pedal bushing issues or TPS, I have yet to do the Bentley test on the TPS.

Symptoms are:

-Every time I use gas sticking revs, 600-1800 high, pulling gas pedal back resolves this (leading to bushing suspicion)

-here's the kicker though, when cold started for first couple minutes, nearly 0 response from heavy throttle pedal useage, then all of a sudden after certain short period, will rev perfectly normal again. (This leads me to believe heavily TPS)

I'm assuming the TPS is designed to compensate for a window of a couple mm of default pedal placement and corresponding idle, which is why bringing back the pedal has had me confused, an I correct?

[struka]

Do you guys buy BMW OEM TPS or an after market one?

Sent from my Pixel XL using Tapatalk

[Layne]

Sorry for bumping an old thread, by am also trying to determine whether I have pedal bushing issues or TPS, I have yet to do the Bentley test on the TPS. Symptoms are: -Every time I use gas sticking revs, 600-1800 high, pulling gas pedal back resolves this (leading to bushing suspicion) -here's the kicker though, when cold started for first couple minutes, nearly 0 response from heavy throttle pedal useage, then all of a sudden after certain short period, will rev perfectly normal again. (This leads me to believe heavily TPS) I'm assuming the TPS is designed to compensate for a window of a couple mm of default pedal placement and corresponding idle, which is why bringing back the pedal has had me confused, an I correct?

The TPS can't control the engine speed at all, it's only a feedback device. Something is definitely binding.

[Layne]

Do you guys buy BMW OEM TPS or an after market one?

If you can find a Bosch from a source other than BMW, it will probably be exactly the same for a lot less money. I would not buy any of the cheap brands.

[struka]

If you can find a Bosch from a source other than BMW, it will probably be exactly the same for a lot less money. I would not buy any of the cheap brands.

That is what I thought. I may try to get one out of the E36 from a junk yard as the one on my car has 312k miles on it.

[ross1]

My 1994 530i does the same thing but it does it constantly from the minute i start my car to actually driving the car it sticks at like 4 to 6k no matter if it is idleing or not really confused on if it might be a bad tps i just bought a new one recently if its sticking could it have something to do with the throttle cable or the throttle body dirty(has been cleaned before) when it did this problem the first time(found out it was a vacuum leak we fixed the problem by capping the leak) or possibly need a new accelerator pedal assembly(i be heard it could be the cause of it too)

Does your car have ASC? If so the second throttle body for it uses the same sensor so you have a "spare" to swap for "testing".

[polygaryd]

I have a 1997 318is eith 193k miles that just started having issues with the engine cutting out while in park or drive, almost immediately after clearing the codes the check engine light turns on and the codes from my obd2 scanner come up as p1765, p1140, p0120. I had taken the car to a shop for this issue and they replaced the tps already with a non oem bmw part. I unplug the tps and the car runs much better, no engine cut out, or shifting issues like before. Also the traction control and the transmission fault light comes on and stays on after restarting the car if tps is plugged in.

I know this isn't a 5 series like you're talking about in this thread but I used this post as a guide to measure the tps on the car and off the car as well as two brand new ones from Parts Authority and Oreilly's. None of which worked all had the same symptoms just at slightly different rpm levels. I do have one coming from bmw btw.

my findings are as follows

tps screwed to the throttle body still:
with key on but car off, leads between pin 2 and ground of connector (connector unplugged from tps) is 5.76v
pin 1 to pin 3 is 3.96k ohms
pin 2 to pin 3 range is 1.257k ohm to 3.981k ohm
pin 1 to pin 2 range is 4.31k ohm to 1.588k ohm

tps off the thottle body:
pin 1 to pin 3 is 3.93kohms
pin 2 to pin 3 range is 4.72k ohms to 0.765k ohms
pin 1 to pin 2 range is 0.773k ohms to 4.72k ohms


Are these ranges normal for a 1997 318is or should they be as your post suggests with a range of 1k to 4k? im assuming 0.773k to 4.72k is too far outside the range the ecm is looking for but im on here to check with you guys. Thank you for any help you can give me.

Note: my asc tps is different in size and mounting hole width so i cannot use this to test even though it is an oem bmw part.

[shogun]

I suggest you make a new thread for your problem on the 1997 318is in the General BMW mechnical help forum https://www.bimmerforums.com/forum/f...ean-Auto-Parts
There are some pro Auto Tech's which have access to alldata etc., maybe they can help.
You can link this thread there in your new thread for info

[myeshia91]

Will a failed TPS stop a car from staying started by itself? My car only stays started when i continuously give it gas and when i stop, it just shuts off. I was told that my engine was flooded. Also, the stomp test hasn't been working on my car for several months. Could the TPS cause this also?

[cirrusblau]

Also, the stomp test hasn't been working on my car for several months. Could the TPS cause this also?

Could be. The stomp test is activated with repeated WOT signals.

[affende]

I wanted to add a small tidbit to this after i had a TPS fail momentarily in 2015.

I went camping / hiking with my brother is 2015. 7 miles of Trailhead road, pretty washed out, extremely bumpy and dusty. Made it up just fine .... stayed 2 nights and headed out on sunday. The last mile of the road threw a CEL, would barely idle, no acceleration, completely undriveable ..... 300 miles from home in the middle of the Rocky Mountains. Took an hour to get the stomp test to work, took another hour to get a cell signal good enough to check the code and it pointed to a failed TPS. Sunday mid-day and very few places are open ... no good tools. Finally got the home number of a "euro mechanic" that "sometimes works on bmw's, i guess" ... spoke with him and he confirmed it sounded like a bad TPS .... days to get a replacement sent in.

He told to be to try winging it back and forth, fully open and let it snap closed ... sometimes it will knock the dust out or get the contacts to work. so i sacrificed a squirrel, painted a face on my volley ball, and started winging it back and forth ... probably 50-60 times and kept trying to start the car after every 10 or so.

finally it worked, car ran better and better the longer i drove it .... i just kept cycling the throttle as i drove (not hard to do in the rocky mountains) ... drove straight home without stopping, ordered a new one .... and kept the new one on had for another year until i HAD to change it.

so if you get stranded .... try that trick ... it saved my ass once, but im not counting on it to work again ... so i keep a spare in the glovebox.

[CamE32]

• Open the throttle valve manually and check the resistance between the terminal 1 and 2 changes.
•Check the resistance in three different positions of the accelerator pedal.
•You may record a resistance of approximately 10-ohms when the accelerator is fully, 2 to 10-ohms partially depressed and 2-ohms when completely released.
It is good idea to go through the manual for specific information which may inform you whether you need to change the TPS or for that matter any of the car's auto parts.

How do I know which are terminal 1 and 2?

[cirrusblau]

How do I know which are terminal 1 and 2?

It will be marked at the base of the pins.