Hey guys so here is the deal with my S80 T6

Its in Limp Mode,

with Check engine codes P0715 and P0756

These are some of the things i have done

I have changed Both solenoids

i have changed TCM

I have changed the Transmission oil

i have checked fuses

i have disconected abs harness

I have left car disconnected from battery for 24 hours (15 min should have been enough)

Here some other information -

When i use OBDII and erase P codes it comes back on INSTANTLY
does this mean its a wiring problem?

I have spent countless hours trying to figure out the problem i have also bought a ALLDATA packet for the volvo but surprise surprise no help there

 

Quick search returned these results:

P0715 - Turbine Shaft Speed Sensor Circuit
P0756 - Shift Solenoid B Performance or Stuck Off

 

What year is your vehicle?

 

I probably know this 0715 is an input speed sensor fault. It could be activated by a difficult mistake in cabling, but the indicator itself may go bad as well.