Peugeot Boxer, fault codes and turbopressure

[GiveMeABreak]

Ok, so there is a maximum operating temperature of 850 °C and a maximum permissible temperature of 900 °C for both the Upstream and downstream temperature sensors (1343 Downstream & 1344 Upstream on the previous electrical circuit diagram). If you are getting 1271 °C, then the sensor is at fault I suspect.

Again - check the wiring harness for a break / heat damage.