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Matt, Mechanical Engineer
Category: Ford
Satisfied Customers: 22758
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I have a problem with a Ford Mondeo 2007 2.3 Accelerator

Customer Question

I have a problem with a Ford Mondeo 2007 2.3 Accelerator Pedal Position Sensor. The car is giving fault codes P2126 and P2127.I believe these are:P2126 - Throttle/Pedal Position Sensor/Switch 'E' Circuit Range/Performance
P2127 - Throttle/Pedal Position Sensor/Switch 'E' Circuit LowI have looked at PIDs and get the following:
Pedal unpressed:
APP1 0.4 V
APP 2 0.0 V
TP1 4.03 V
TP2 1.47 VPedal pressed:
APP1 3.27 V
APP2 0.0 V
TP1 1.21 V
TP2 4.47 VI've connected a picoscope to pin 2 of the pedal and get:Unpressed - 0.431 V
Pressed - 3.255 VWaveform is smooth throughout pedal press/depress.On the other pins I get:1 - 0.5 V - Guess 5V reference
2 - As above - Guess Analogue signal
3 - 0 V - Guess Analogue ground
4 - Ground
5 - 0 V
6 - As aboveI'm guessing that terminal 5 should be the PWM reference voltage (12 V?)
I'm also guessing that this is fed from fuse 4 in the central fuse box.Please could you have a look at the data above and my assumptions and let me know your thoughts on what's causing this?I was expecting a PWM signal between pin 6 and ground.
Submitted: 7 months ago.
Category: Ford
Expert:  Matt replied 7 months ago.


looking at the numbers I'd say the TP1 value is too high at rest?

as there are 2 tracks in the pedal one goes high with motion the other goes low and they cross over at about halfway up.

so the range on both TP's should be the same voltage but TP1 has a range of 2.8v and TP2 a range of 3v? so I suspect there may be an issue with the pedal sensor

have you tried just disconnecting it and cleaning it with switch / contact cleaner?

Customer: replied 7 months ago.
Hi MattThe problem was more that only one of the accelerator pedal position sensors weren't working and I was struggling to determine how the PWM signal was set up with this model.
The throttle position sensors will be high as the throttle sits about 20% open as there's no separate idle air control.
I managed to get hold of a wiring diagram and found that the PWM 12V supply was fed to pin 6 of the pedal and that the PWM signal to the PCM was on pin 5.
The fuses were good so I traced the wiring back to the fuse box and found a break in the 12V supply wire. Soldered it back together and it now works fine.
Expert:  Matt replied 7 months ago.

Glad you got it sorted and thanks for letting me know

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