No diagnostic fault codes ever say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. First your mechanic will perform electrical tests on the circuit to rule out wiring and mechanical problems before spending your money on parts.
If you want to know how to diagnose a fault code, it would make it a lot easier if you would list which codes you're getting. There's well over 2,000 potential fault codes, so it doesn't pay to guess.
Wednesday, September 30th, 2015 AT 11:06 PM