Flashing red light part 2

[Coeurdelion]

Hi again ,follow on from my intermittent flashing red light problem, as previously stated sometimes it flashes fast ,stops flashing and engine starts ,sometimes stays on for 3 seconds ,goes off then starts other times change of key to spare then usual key a few times and it works ,found a load of codes in a bill for the replacement of a crankshaft sensor ,(all in Frenchas its french) just before I purchased the van
U1900 can communication bus fault
P0404 exhaust gas recirculating 'A' control range performance
P1665 injection pump control module communication
P0053 heater resistance bank 1 sensor 2
The crank sensor replacement was p0335
Two I cannot find the translation for are
P3500 and c1303 ?
I'm thinking maybe the codes were cleared after doing the replacement of the crankshaft sensor to help sell it ,I actually got it home no problem but wouldn't start after being parked up ,it was taken to ford where the codes were read and fuses changed, 100 + € bill,all okay until next trip out ,starts after flashing red light stops flashing and runs great apart from a bit slow setting off in 1st gear,the van is back to normal now as i lept swapping keys until the light stayed on red for 3 seconds then went out so back to normal!!!!anyway long post but I'm going to book her back into ford and see what they say this time ,I'll keep you posted
I've been advised to but a reader and forscan but I can't fix the problem myself so feel like I'm wasting money
Coeurdelion