NefMoto

I have an Audi 2.7t in a Porsche Boxster. I'm struggling to get the drive by wire throttle to work, getting codes

18039 - Accelerator Position Sensor (G79)
            P1631 - 35-00 - Signal too High
18042 - Accelerator Position Sensor 2 (G185)
            P1634 - 35-00 - Signal too High

The Porsche uses a similar style pedal sensor to the Audi TT 1.8t so I tried one of those also but got the same codes.

(http://i65.tinypic.com/fw3mg2.jpg)

I have no EPC light wired up and a ABS communication error, could either of these contribute to the error (I assume not). I know it's common for these codes to be related to blow ground circuit on the rear 02 sensors but i've wired up fresh grounds to the throttle ground wires so it's not that.
 
I have no traction control and the early Porsche Boxsters have a cable throttle so i'm considering going that route. What needs to be done to make the ECU happy? I have a 75mm B5 RS4 throttle body, are there any cable throttles that size?

It fries the ECU and it needs replaced.

My ECU is fine, checked it. Any idea about going cable throttle?

Install the OE pedal from the donor car. Going cable will cause more issues than mounting another pedal, in addition to killing a lot of functions the ECU has.

The Boxster has a floor mounted pedal so fitting an A4 or A6 pedal won't be an easy or neat looking solution.

What ECU functions would I loose? (I have no traction control or cruise control)

Might want to try pedal sensor from facelift D2 A8 petrol (p/n 028 907 475 BD). I haven't tried it with 2.7T ECU (as I don't have one) but it surely works with 1.8T ME7 ECUs.  ::)

Thanks, I'll look into that. My thinking was the Audi TT one would have worked as it's me7 also. It turns the other direction and the values were the wrong way around, showing full throttle when the pedal wasn't depressed.

I think you can fix that by finding out which pins in the connector represent what sensor and swapping them with each other.
There are basically two potentiometers, one is showing "full open" in "default position", the other "full closed".

I've tried that, it swapped the sensor's values around but not the fact they are showing full throttle with the pedal not pressed.

The Porsche pedal sensor had closer values, showed the correct readings for off the throttle but only showed 60% on full throttle rather than 80% my mates S4 has.

I assume you're re-aligning the throttle body in between tests?

Yeah, i'm re-aligning it each time.

I bought a pedal from a 1.8t B5 Passat (same part number as the Audi), the pedal readings are spot on, same as my mates S4 is. I still have the fault codes.

Everytime I search for them it comes up with people that have shorted out the 02 sensor wiring and blown the ECU, i've not had any fault codes for the lambda sensors and i've opened up my ECU and it's looks fine.

I'm running out of things to look into. Considering sacking it all off and going standalone.

I would try another ecu first.

I'm using an Audi RS4 throttle body, is there any coding required when using that?

I believe so, but only when it comes to mapping, not the issue you're having. Why not put a stock throttle body on to eliminate the possibility? Having 3-4 different cars worth of components all meshed together...Nobody is going to know unless they've dealt with the exact same combo, which it doesn't look like anyone has.

That's why I've taken the decision to go standalone. ME7 is too complicated for me to get right considering the amount of changes I've made. Should have done it right from the start. I was hoping for more compatability between Porsche and Audi systems as they are both the same year, same parent company and both run Bosch ECU's. Thanks for the advice.

Still think you should try another ECU.

I tried my ecu on my mates S4 and it showed the fault so it's damaged. Still going to standalone now though.