To whom it may concern.
I work at a landrover dealership as a tech and have recently came across a similar fault.
The vehicle idles and starts no problem, but just won't rev up.
Had the vehicle on T4 diagnostics and checked real time data for driver demand 1, 2 & 3. Voltages were moving up and down when pedal pressed. so appeared pedal potentiometer was working okay. Checked for the supply to pedal, even carried out continuety and resistance checks on wiring from pedal to ECU, All checked out okay.
Called landrover technical and was told to try ECU as we had already substituted pedal. Fitted ECU and prorammed injector codes and new security code, but still didn't work!!
Called technical again, this time i was told to splice new wiring from pedal to ecu, did this to all the wiring and fault was still there.
Pulling my hair out and still not getting anywhere, i started checking other wiring to the ECU. With vehicle running i was getting 13.82v at pin 30 on the ecu(green/white wire). This wire goes to the instrument cluster.
Took dash out (two screws) and dis-connected multi-plug( if sitting in drivers seat, the multiplug on the left) it has the green and white wire.
With the multi plug dis-connected, i started the vehicle and it will now rev up!!
There must have been a short in instument cluster causing a wrong signal to the ecu and giving a driver demand problem
A new one is on order and costs just over £100 + vat.
Hope this helps someone, as it took the best part of 2 days to find the fault.
Please note that i haven't quoted connector numbers etc from wiring diagrams as i'm writing this from memory at home.