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Old 14th November 2021, 20:27   #1
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Default Clio RS throttle body TPS voltage issue.

Long shot but I need some help with addressing the voltage issue I have with the Clio RS throttle position sensor.

The issue is that at wot it goes to 4.90v and it's seen as idleing speed for the ECU and when it does this the engine just bogs down and looses all power.

I'm using the original Clio RS throttle position sensor,I can't use the Saxo one as it rotes clockwise and the Clio one anticlockwise.

I was told it was possible to calibrate the tps trough the Lexia diagnostic which I bought just for this but there no option for that,only to calibrate the idle stepper motor,I believe it might only be the single plug ECU that has this option? I have a three plug.

I've tried swapping wires but it just makes it worse,i also have another Tps from a different brand but it reads the same voltage.

The link below is to a YouTube video that shows the voltage change in real time using diagnostic as it makes it a bit easier to understand this way, thanks for any help.

https://youtu.be/gR_VfCXP0Dc

Last edited by VeiRoN; 14th November 2021 at 20:29.
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Old 15th November 2021, 21:58   #2
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Quote:
Originally Posted by VeiRoN View Post
Long shot but I need some help with addressing the voltage issue I have with the Clio RS throttle position sensor.

The issue is that at wot it goes to 4.90v and it's seen as idleing speed for the ECU and when it does this the engine just bogs down and looses all power.

I'm using the original Clio RS throttle position sensor,I can't use the Saxo one as it rotes clockwise and the Clio one anticlockwise.

I was told it was possible to calibrate the tps trough the Lexia diagnostic which I bought just for this but there no option for that,only to calibrate the idle stepper motor,I believe it might only be the single plug ECU that has this option? I have a three plug.

I've tried swapping wires but it just makes it worse,i also have another Tps from a different brand but it reads the same voltage.

The link below is to a YouTube video that shows the voltage change in real time using diagnostic as it makes it a bit easier to understand this way, thanks for any help.

https://youtu.be/gR_VfCXP0Dc
Can you rotate the TPS sensor in its housing if you loosen the screws? I would set the throttle to WOT and then turn the TPS until it shows full load.

Failing that, you could fit a throttle stop at about 90% throttle. Anything over about 80% doesn't really affect air flow or power.
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Old 15th November 2021, 22:42   #3
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Can you rotate the TPS sensor in its housing if you loosen the screws? I would set the throttle to WOT and then turn the TPS until it shows full load.

Failing that, you could fit a throttle stop at about 90% throttle. Anything over about 80% doesn't really affect air flow or power.
No unfortunately the tps fixing holes don't allow any adjustments, I've looked around for the same tps that allows slight adjustment and was actually able to find one seemingly (picture below),but what looked right in the advert pictures wasn't what I had received as it turned out to be the same one that I have so had to send it back.





This is what the throttle body looks like at 4.70volts, anything more it causes the issue described, it's not really a problem for 1st and 2nd gear,3rd can be annoying and 4th and 5th gear aren't very useable if not with light pressure.

I did fit a stop using a bolt bolted to the floor and I think I'll go back to it for the time being.

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Old 15th November 2021, 23:26   #4
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Very strange as the sensor is virtually identical to the saxo one.

It must be wired different internally I presume?

Have you changed any wiring on the engine loom itself?
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Old 15th November 2021, 23:59   #5
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Very strange as the sensor is virtually identical to the saxo one.

It must be wired different internally I presume?

Have you changed any wiring on the engine loom itself?
No the only change I had to do was swap around the tps wiring to get a reading,I did use some spade terminals momentarily until things work properly but I wouldn't have thought they would make much difference to the voltage read out.
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Old 16th November 2021, 20:31   #6
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No the only change I had to do was swap around the tps wiring to get a reading,I did use some spade terminals momentarily until things work properly but I wouldn't have thought they would make much difference to the voltage read out.
You have tried all of the possible combinations?

I've got an aftermarket ECU and wiring my TPS took 4 attempts! one of the attemps did have a similar result in that it would only see partial of the sweep.

just a thought. Im at a loose end
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Old 16th November 2021, 21:10   #7
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You have tried all of the possible combinations?

I've got an aftermarket ECU and wiring my TPS took 4 attempts! one of the attemps did have a similar result in that it would only see partial of the sweep.

just a thought. Im at a loose end
I did try every combination that I thought of but it's worth to try again.
This time I'll write down every combination as I do it just to make sure as I haven't done that last time, thank you for the help.
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Old 18th November 2021, 19:46   #8
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Just to update I did try all the combinations but it just makes it worse.

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Old 23rd November 2021, 09:16   #9
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Peugeot sport added a modification to the 206 Cup cars that used the 48P ECU with a resistive potentiometer.

I've never looked into what they did but I assumed that it was because of the differences between the original 'hall proximity' type position sensor and the resistive type.

If you have more than zero volts on the signal wire when the wire is not connected then there must be a 'pull-up' resistor in the ECU. If you remove that resistor you may get a suitable range of voltage.

By the way, modifying the throttle spindle is a bad idea. I've seen them crack across the screw hole after a while and the screw then disappears inside the engine, causing lots of damage.
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Old 23rd November 2021, 14:21   #10
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Peugeot sport added a modification to the 206 Cup cars that used the 48P ECU with a resistive potentiometer.

I've never looked into what they did but I assumed that it was because of the differences between the original 'hall proximity' type position sensor and the resistive type.

If you have more than zero volts on the signal wire when the wire is not connected then there must be a 'pull-up' resistor in the ECU. If you remove that resistor you may get a suitable range of voltage.

By the way, modifying the throttle spindle is a bad idea. I've seen them crack across the screw hole after a while and the screw then disappears inside the engine, causing lots of damage.
Thank you for the help, I'm aware of the throttle spindle as I had read one of your posts a while ago mentioning it,not sure how to fix that, however regarding the readings I took some pictures.

Unplugged voltages are:


Pin 1:


Pin 2:


Pin 3:


Plugged in.

Pin 1:


Pin 2:


Pin 3:


Battery was flat so some voltages might be a bit lower sorry about that.
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Old 24th November 2021, 19:44   #11
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Pin 1 is the signal wire and there's obviously a pull-up on that pin.
If you open the ECU and trace back from the pin you'll find a resistor with a higher voltage on the other side of it. Removing the resistor will reduce the voltage on the pin and might solve your problem.
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Old 24th November 2021, 21:54   #12
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Originally Posted by Chipwizards View Post
Pin 1 is the signal wire and there's obviously a pull-up on that pin.
If you open the ECU and trace back from the pin you'll find a resistor with a higher voltage on the other side of it. Removing the resistor will reduce the voltage on the pin and might solve your problem.
Thank you, I've sent you a PM regarding this.
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Old 25th November 2021, 17:58   #13
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I've traced the wire back and it is the number 4B on the ECU pins side.

Second wire from bottom right,above the white wire.









Second pin from top left,smaller plug.



This is as far as I will go as I don't know what I'm doing and I don't want to ruin my ECU especially as there's Wayne's map on it.

Last edited by VeiRoN; 25th November 2021 at 20:18.
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Old 4th December 2021, 21:37   #14
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In the end I just put a 1.8k ohm resistor on the 5v feed wire and the maximum I get is 4,55v which is full load.

Last edited by VeiRoN; 4th December 2021 at 22:11.
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