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Throttle Position Sensor (TPS) resistance values & error code

pietrzj

Spa-Francorchamps
Joined
19 Mar 2014
Messages
309
Throttle Position Sensor (TPS) resistance values & error code
 
Anyone tested their TPS with an ohmeter?

I am intersted to know if the resistance is supposed to vary between pin 1 & pin 2. ine seems fixed, with only oin 2-3 valrying with throttle position.

Just bought a new (not genuine) TPS (Magneti Marelli) and that ist the same. Not the same valus, but only varying between pin 2 & pin 3.

Voltage inputs to the TPS are correct
 
Bentley manual suggests Pin1-2 should be 1600-2400 and pin 2-3 710-1380, but I have spotted a few errors in the manual over the years, so wondered if anyone out there had some real world values to help me.

Error code showing is 15.
 
Must read my text before hitting send :)

I am intersted to know if the resistance is supposed to vary between pin 1 & pin 2. Mine seems fixed, with only pin 2-3 varying with throttle position!
 
Chances are the car's TPS wasn't set correctly or has been knocked out of alignment.

Undo the bolts that hold the TPS in place and rotate it till the scantool is reading correctly with the throttle plate closed. Tighten down the bolts and then operate the plate by hand to full throttle and check the reading.

You should be able to then install the cable and be done.
 
As I understand it, Pin 2 is common, the DME takes its reading across Pins 1 abd 2 expecting resistance values of between 1600 and 2400 ohms and across pins 2 and 3 with resistance values of 710 to 1380ohms.

So your TPS appears to be faulty.
 
Thanks both. The issue is I don't believe in coincidences. If my original labelled "Bosch" TPS is reading a fixed resistance between pin 1 and 2 and a brand new sensor is also reading a fixed resistance between 1 and 2, then I conclude that this is the design intent and the manual is wrong. Pin 2 is not the common pin. I believe pin 3 is the common pin, because as my readings show, pin 1 to pin 3 also has a variable resistance. I have attached a very basic diagram of my view of the circuit and the readings for existing and new (tested with the cable disconnected).

It is worth saying that the Bosch unit was on the car when I bought it 9 years ago, but it is not known if it is the car's "original". In all that time I have had the TPS error code.

I have put below the readings from both new and old TPS incase anyone is interested. I am going to fit the new one and I will post again when that is done to say whether the straight swap out has improved the situation.

A genuine replacement part is over £400 and the cheapest on the market is less than £30 so even if the life of the unit is reduced, it still seems a significant saving (if indeed my understanding is correct and its not only th egenuine ones that really do have a variable resistance between pin 1 & pin 2.
 

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Typical ! ...
I decided to plug up the new TPS to see if I could clear the blink code with it. As a precaution I thought I would check to see if the the code was active once more (I was looking for a 1_15), however, what I got was completeley different and has put a stop on the job in hand for now. The code I got was 4 digits, so not a format I have seen before... 1_2_1_6

Anyone know what this is? Its now the only code showing and the 1_15 is no longer present.
 
When you say blink code, are you refering to the codes provided by the check engine light and having the throttle fully depressed with the ignition on?

If so, I don't believe that that system works on UK vehicles.
 
Really? why don't you think it works? Something happens when I do what the bentley manual says (but it is American). It certainly flashes. If you are sure maybe I need to create some deliberate faults by unplugging sensors and see if it reports anything.
 
I believe the Check Engine light blinking feature was mainly present in US cars, but I have also heard that some ROW engine control units had this feature.
Cheers,
Tore
 

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