None start

[Lufcrules]

Hi folks
Due to illness I’ve not used the car for a few weeks come to start it this morning and it just about starts but erratic revs up and down then cuts out .
Engine check light on
Battery voltage is good as it’s on a trickle charge
It’s throwing up the following codes
P1502
P1516
P0638
Any suggestions on where to start it’s a 2004 c2 3.6 manual.
Thanks

 

[Kersidan]

Try Googling each code, it's surprising what info comes up. P1502 is a DME code indicating it can't read the correct throttle/idle position. First step is to clean the inside of the throttle body carefully, dson't use carb cleaner or anything aggressive.