U0100 -05 sts no start 30 min.and brake pedal very hard

Question

car no start 2xs now 1st no start brake pedal very hard waited 35 mins. then started, 2nd time no start 2 weeks later not wait as long, put foot on brake pedal, then off then on engine started. codes scanned are uo100,po700,po601,and po420 any ideas? engine runs great but engine light on. this is 2005 sts cadillac

Answer 1

U0100 Lost communication with the ECM

P0601 ECM not programed

The ECM is not for this vehicles. or its just does not have the program for it either way this is a ECM failure. Whatever other code appear will be invalid as long as P0601 is present