Technical Panda 100 hp throttle problem

[Vrt216]

Hi my 2007 panda 100 hp has a problem with it not revving up past 3800 while driving, it's fine when in neutral, the check engine warning light and message are displayed on dash, I have read fault codes and it comes back with. P0120 accelerator pedal potentiometer 1. I have replaced throttle pedal but none better, any help would be appreciated thanks

 

[A3jeroen]

I'd check the throttlebody and TPS and the wiring.

gr J

 

[Vrt216]

Does the whole inlet manifold need too come off for me too remove throttle body? Also where is the tps, i thought it was inside the throttle pedal assembly. Thanks

 

[A3jeroen]

Throttlebody should be on the batteryside and bolted with 4 bolts. Normally this has a TPS that is used to check the values of the pedalsensor.

gr J

 

[koalar]

I am confused. A quick Google search and some sites have it as either ?


P0120 Throttle Position Sensor/Switch (TPS) A Circuit Malfunction

Or

http://repairpal.com/obd-ii-code-p0120





Guess both can be shortened to TPS but which one is correct.



One has to be wrong but which one

 

[Vrt216]

Ok so i got the throttle body off the car, it looks in good condition, not soated up or gunked, so guess il just have too try a new one hope thst solves the problem.

 

[A3jeroen]

Multimeter for changing resistance/Voltage.

gr J

 

[DigDug]

There's a double potentiometer on both the Accelerator pedal sensor, and on the throttle position sensor.
The two are linked by an ecu map of accelerator pedal (read: user power requested) to throttle position (read: actual power given)

I read in the eLearn that there's two potentiometers ( on both accelerator position sensor, and on TPS) so that if one fails, it can use the 2nd as a backup. Whether this affects the maximum throttle opening or not I don't know (I wouldn't have thought so though).
If your fault code is on accelerator position, I'd guess that the throttle position sensor is fine. Have you checked the wiring terminals to make sure they're not loose/corroded?

As said above, a multimeter combined with the wiring diagrams in eLearn would go a long way as to determining the reason for the fault code. I'd check the output of potentiometer 1 on the accelerator pedal first.

Wiring diagrams (also in elearn) https://www.fiatforum.com/panda/199375-100hp-ecu-wiring-diagram.html

see this post too : https://www.fiatforum.com/panda/436196-panda-100hp-woes.html

 

[DaveMcT]

Did you use a new or used throttle pedal assembly?

 

[irc]

I think both potentiometers are used all of the time, and the ECU compares both. If they do not match it throws an error, and uses data from one, but with limitations.
At least thats how the last one I looked at closely worked (italian "supercar", aka electrical nightmare). It's a safety feature to stop uncommanded throttle opening (e.g. failed potentiometer or wiring fault) leading to accidents.
I suspect it is similar on all drive-by-wire cars, but I don't know for sure.

 

[koalar]

Can we not test the peddle with multiecuscan similar to below

Ignition on. Engine off



At least that would confirm the peddle and wiring to the ECU

 

[Vrt216]

Have fitted used parts but to no success. I will have check the voltages, multiplugs all look in good condition.