Newbie just joined for Help advice needed please for P2125

[Lisa2022]

Hello to all here
I’ve just joined due to not being able to find a local mechanic to help.
Ford fiesta p2125 fault code on 5-6 occasions
Error code found on breakdown man’s machine
Car goes into limp mode
Turn ignition off then on again car dash warning goes off and car drives normal
Mpg in my opinion has gotten worse 160 miles from £40 of petrol 2 weeks ago
Fiesta 1.25 Zetec 63 plate full service history and I’ve had sparks etc changed looked after since I bought it in 2018
Mpg seems to have gotten worse fault code appeared 2019
Breakdown and warranty policy useless
I’ve bought 2 OBD2 scanners
Tried both and both read
TP - 14.1 14.5 % percentage at idle stationary after driven 20 minutes with temp gauge at the usual half way point
Tried slow revs up to 2500 rpm and the TP percentage isn’t moving isn’t increasing
I’m presuming TP means throttle position on the OB2 scanner ?
I’ve recorded and photos of the basic scanner live data
Odd occasions petrol gauge needle goes up to full and sticks then after a drive or next day it drops back to normal position. The digital miles left sometimes fluctuates goes up and down.
Weird tinkering rattling noise intermittently from underneath maybe around manifold area
Headlights flicker slightly
Sorry members for long details but just wondering if it’s all related and if anyone thinks the car needs repairs?
Any ideas ?
Only tried a few local mechanic and being told to carry on driving told car has no major issues that they don’t know what to repair and nobody wants to manually inspect or look at live data
Was hoping someone on a forum with similar car issues might have some good advice
Thank you
Lisa

[Penelope Stopit]

Too many things to tackle in one go

Could start off by asking someone to check why the headlights flicker

Headlights might be flickering due to the alternator voltage regulator failing

If voltage regulator is causing intermittent overcharging or no charge it could also be causing other circuits to have problems

[Lisa2022]

Hi Penelope
Thank you
Yes I know too many problems
Does alternator need checking with a obd mechanic scanner or a multi voltage reader ?

[Penelope Stopit]

Multimeter set to volts

Check voltage at battery when lights are flickering

[Lisa2022]

Thanks I will get another mechanic appointment. Local mechanic put scanner on it Thursday and another code was U300F ignition input accessory and he hadn’t got a clue what it meant. They said they don’t know why it’s using too much fuel. They want to check the emissions. I’ve tried 3 mechanic garages and nobody wants to investigate. It’s been up on ramps been visually checked had spark plugs checked, wheels checked. I’m getting different answers because one mechanic said replace the throttle body and the others said could be a TP sensor and another mechanic said he wouldn’t touch an electric throttle body drive by system because they need re programming. So basically I’m struggling to find anyone to properly check the TP and it’s components related to it. I’m frustrated 😬 scared it’s going to cost 1 k to fix

[spikeyhead]

You need an auto-electrician not a mechanic.

[Hammer67]

http://www.bba-reman.com/forums/Topic174069.aspx

This may be of some help.

Your issues look similar.

[Lisa2022]

Hi Hammer
Thank you for reply trying to help
Wow way over my head now
The auto electrician I know are family members and they say replace the throttle body but I don’t think that’s going to stop the p2125 fault code.
Going to have to phone around for another auto electron.
It’s not like the car isn’t driving nice it’s the fuel costs spiralling out of control which frustrates me 😬😩
Will print the information link off to study show auto electrician see if it helps me
Thank you much appreciated 👍

[Hammer67]

I`d have a phone round your local Ford dealerships.

If your issues are a known fault it could be a simple fix.

It "could" be as simple as a bad connection at a multiplug that simply needs a clean/grease/reconnect.

I certainly wouldn`t start changing parts or engaging random unknowns to look at it.

[NMNeil]

Penelope Stopit said:

Multimeter set to volts

Check voltage at battery when lights are flickering

Then set the multimeter to AC voltage. If it reads above 50 - 100 millivolts AC the alternator diodes are probably bad, which would cause the flickering lights and possibly set unrelated codes, as the computer is getting too much ripple on the 5 volt reference.

[Lisa2022]

Aww thank you so much for advice
Yes I’m worried about changing parts as I know it’ll escalate to more and more parts as I’ve had similar gremlins on other cars and ended up wasting hundreds of pounds

[Lisa2022]

Just reading up on C90 connection which I think is in the engine bay pcm fuse box to ECU which is now really scary for trusting someone to look at. I’m hoping it’s not ECU wiring breaks. Seems all too complicated. May have no choice but to trust Ford auto electrician. Will start with getting battery and alternator voltage readings first.
Print out info from you guys and do some research reading.
Appreciate everyone’s knowledge and help. You guys are all brilliant 🤩

[vw_99]

Broken wire under or around battery tray.
Usually causes tank sender unit fuse to blow and enter limp home mode.
Same loom has TP wire on it.

Might be worth a look.