Hello. Today I turned off the codes on a 90s Buick shelf (code 42) because the vehicle runs round and gives something “hangs” when the gas is running. Code 42: The EST signal did not change when the ECM applied baypass voltage to the registration module. No real impulse from the ignition module !? Or even cable tree ? – rev indicator does not work either. Now the following has been changed without success on the car: ~ ignition cable + candles ~ ignition coil ~ ignition module What can it be or how does it work? s problem. A trip over 120 km I would hate to trust the car I am very grateful for any help !!!