Transit 2.0 di 01 Duratorq P0235 Turbocharger boost sensor

[andy gladish]

Hi All. This Transit goes into limp and has the same code that reapears after a short drive for,

P0235 turbocharger boost pressure sensor A circuit malfunction.

I have fitted a donor boost sensor that didnt help.Also can someone tell me how or were the air intake is calculated from as it appears to have no MAP or MAF but i can view live data for MAP using Autodiagnos. All vac hoses intake hoses turbo compressor outlet hose seem to be in good order and connected.Clean air filter.

Thanks for looking
Regards Andy.