DTCs 2127 & 2128

[Sngx1260]

I am working a on Voodoo swap in a 68 Mustang Fastback. This is a seven year project that is nearly complete, but I have run into some electrical gremlins that I am not sure how to solve. I have worked through the Ford Service DTC flow chart on both of these. My issue is the the APP2 is registering low voltage. It is supposed to be between 4.5V and 5.5V. It is at about 2.2V. The battery is fully charged and APP1 registers 5V. I have worked through the rest of the flow charts and have no other issues with resistance.

Any thoughts?

Thanks in advance.

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[stanglife]

what is app2? 5V is going to be a reference voltage for most sensors/actuators and anything less is the return signal. It's been a while since my last swap.

 

[Sngx1260]

what is app2? 5V is going to be a reference voltage for most sensors/actuators and anything less is the return signal. It's been a while since my last swap.

APP refers to accelerator pedal position. On this pedal configuration there are apparently two sensors. The APP1 registers the proper voltage AND when i data log through HP Tuners it shows the pedal movement. For APP2, it does not have the proper voltage AND does not show pedal movement in the software.

 

[stanglife]

Ok - that's familiar. I think since it's drive by wire - those are for redundancy. I can tell you that I once burned up a pedal assembly while trying to install an auto-blip - had to buy another pedal/dbw sensor.

 

[Sngx1260]

In this case, I believe I have isolated it to either wiring or to the PCM. I am fearful there is a problem with the PCM and I am not sure how to diagnose that.

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