I did not find this myself so I cannot take credit for finding the fault, and in fact I did not actually even see it myself, but I looked at the car few times and failed to find the problem, and the explaination given to me makes perfect sense so I thought I should share.
Initial call out: Car not starting (no crank) after engine rebuild. Fault code P244D found - cat temp too high during regen.
This fault codes needs reset of exhaust temp values in order to clear it. Some people also say ignition (terminal 15) must be on for at least 30 mins before trying to clear the codes.
I cleared it a few times, first time we cleared it, performed successful regen, then P244D came back 1 min after regen. I cleared it many more times, sometimes it would come back instantly, sometimes it would come back.
Checked wiring from ECU to sensor and did not find any fault so my conclusion was ECU not sending 5v refence signal for sensor 1. (Live data for sensor 1 normally showing very high temp, I think approx 800°C).
In the end, I was told the wire for the sensor rubs on the exhaust heat shield if it is not reassembled correctly, and this is what was causing the problem with the 5v signal being shorted to ground, and no fault code indicating short circuit.
Make sense to me, it is quite possible/likely when I was testing wiring I moved the plugs to a position that meant the damaged wire was not touching heatshield.
Initial call out: Car not starting (no crank) after engine rebuild. Fault code P244D found - cat temp too high during regen.
This fault codes needs reset of exhaust temp values in order to clear it. Some people also say ignition (terminal 15) must be on for at least 30 mins before trying to clear the codes.
I cleared it a few times, first time we cleared it, performed successful regen, then P244D came back 1 min after regen. I cleared it many more times, sometimes it would come back instantly, sometimes it would come back.
Checked wiring from ECU to sensor and did not find any fault so my conclusion was ECU not sending 5v refence signal for sensor 1. (Live data for sensor 1 normally showing very high temp, I think approx 800°C).
In the end, I was told the wire for the sensor rubs on the exhaust heat shield if it is not reassembled correctly, and this is what was causing the problem with the 5v signal being shorted to ground, and no fault code indicating short circuit.
Make sense to me, it is quite possible/likely when I was testing wiring I moved the plugs to a position that meant the damaged wire was not touching heatshield.