Hi, so I have a Mk7 fiesta with a throttle position sensor issue. I have replaced the throttle body + pedal for two brand new ones, the issue sorted for a few weeks then returned.

The two garages I used for diagnostics has told me they don't know what it is. I can only deduce that it is an electrical problem. I have been advised to sell the car while it is still working-ish.

The car is in otherwise great condition, full service history, 62k miles on the clock and it does what I need it to do.

It seems a shame to have to sell the car as it's otherwise perfect not to mention how expensive the market is rn.

As a last ditch I'd there anything else I can try, I tried checking for water ingress as it seems to break when it rains but I couldnt find any.

Is there a diagram or something of the wiring loom I can use to know to test continuity of wires / clean contacts?

Is there anything else I can do? The code doesn't show on my obd reader so I cannot tell you the exact one but the garage has said "throttle position sensor"

 

Hi, Throttle Position Sensor is split into two, one in the pedal (throttle demand) and one in the throttle body (actual position)

You would need to wait until the fault occurs, keeping the reader on you at all times, and read when the fault is active.

It could be an instrument cluster fault, next time it happens, bang the dash above the cluster and see if it goes away.

Check the engine earth is in good condition also or even add an earth wire to one of the throttle body mount bolts to the body and give it it's own earth

On 8/29/2023 at 12:57 PM, rory13 said:

Hi, so I have a Mk7 fiesta with a throttle position sensor issue. I have replaced the throttle body + pedal for two brand new ones, the issue sorted for a few weeks then returned.

The two garages I used for diagnostics has told me they don't know what it is. I can only deduce that it is an electrical problem. I have been advised to sell the car while it is still working-ish.

The car is in otherwise great condition, full service history, 62k miles on the clock and it does what I need it to do.

It seems a shame to have to sell the car as it's otherwise perfect not to mention how expensive the market is rn.

As a last ditch I'd there anything else I can try, I tried checking for water ingress as it seems to break when it rains but I couldnt find any.

Is there a diagram or something of the wiring loom I can use to know to test continuity of wires / clean contacts?

Is there anything else I can do? The code doesn't show on my obd reader so I cannot tell you the exact one but the garage has said "throttle position sensor"

 

To have any chance of solving this quickly you need the exact fault code to know where to look.
As has been said above there are multiple throttle position sensors, one at the pedal and one at the throttle body. 
Although there are actually at least 3 throttle position potentiometers. Two in the throttle body and at least one maybe two in the pedal. Any one of those circuits could be the issue.
The car can still drive ok if only one circuit fails. One thing I’ll say is the fact the garage is telling you they don’t know what’s wrong and to sell it should tell you they don’t have a scooby about auto electrics. Your better to go to an actual qualified auto electrician as they are experts and quite often have lower labour rates than a garage who know f all. 

I wouldn’t go banging on the top of the cluster as Fords are known to have poor solder joints on the cluster multiplug and have a tendency to go bad as it is. The last thing you need is further fault codes and problems. 

1 hour ago, thanuttiscotsman said:

To have any chance of solving this quickly you need the exact fault code

🤣 Quickly !! that post was back in August 2023.

Not that it makes any difference since 'rory13' is yet another One Post Wonder.

Joined 29th August, Posted 29th August, Last visited 29th August.