I have these Nissan xtrail but it wrote P1229 NISSAN - Sensor Power Supply Circuit Shorted, and the voltage passing through Accelerator Pedal Position (APP) sensor Power, Steering Pressure (PSP) sensor, Refrigerant Pressure sensor and EVAP Control System Pressure sensor are 12v instead of 5v. What could be the possible fault?
Really obtuse post there godwin. Since you appear to have pasted the causes for a P1229 right off an internet site why did you skip the top most likely cause? Bad harness ground.
Why didn’t you post anything your Nissan is doing along with this code? Does it run and drive? Does the AC work? Waht is this 12v vs 5v issue you posted?
I’m thinking because the voltage is high there is a positive short at the ECM connector or bad ECM. Check reference voltage at the ECM.