Check Engine/ Throttle Position Sensor

[MrStock 5]

Hey,

maybe someone could help me with a Problem that i have till months now and which i cant handle. I have Check Engine light from time to time on, and it readed the Fault Codes, it says 2 Errors about Throttle Position Sensor. I buyed 2 new and screwed them on, but that changes nothing. I installed it as in Haynes told and it changes nothing. Finally i drove it with disconnected TPS and that too changes nothing. Car runs very good, Idle is very good.

Someone has an Idea? Its an 1991 205 GTI 1,9 DKZ.

[jackherer 543]

Check the wiring between the TPS and the ECU plug by measuring the resistance of the TPS itself then measuring the resistance on the relevant pins on the ECU connector.

[MrStock 5]

26 minutes ago, jackherer said:

Check the wiring between the TPS and the ECU plug by measuring the resistance of the TPS itself then measuring the resistance on the relevant pins on the ECU connector.

Should it be the same?

[jackherer 543]

Yes, pretty much. Even good condition wire does technically have some resistance but it's fractions of an ohm per metre so insignificant compared to the resistance of the sensor itself.

[petert 641]

The TPS (M251) is just a three position switch, thus has either zero ohms or is open circuit. There are three conditions - idle, part throttle and full throttle. I can't recall which way it goes, but at part throttle there should be no connection between pin 30 and pin 52 or 53. At idle, there should be a closed circuit between 30 and 52 or 53, then the opposite between 30 and 52/53 at full throttle. It's typical for the idle switch to fail and thus be open circuit. Open fitting a new TPS, many fail to set up idle correctly. You should be able to hear the switch open and close as you crack the throttle off idle. Checking at the ECU with a mutimeter between 30 and 52/53 is the only way to fully diagnose the problem.

[MrStock 5]

So theres the correct signal coming to the ecu, but i fail to get check engine light permanent off even with haynes.

Is it possible to set the position while engine is running, meaning one turns it and the other sees if light goes off?

[MrStock 5]

I changed ECU, Airflowmeter (cause of temperature sensor linked with TPS), checked cables from TPS to ECU. Theres the correct signal coming to ECU.

And even the ECU from my non faulty GTI says TPS Error when i installed it in faulty one. But both cars do have the same OHM coming from TPS.

I really dont know what to do now. ECU warning lamp comes all 60 sec and deletes after 20 sec.

Does anyone has any idea?

Edited July 2, 2018 by MrStock