Code 42: By-Pass Open Or Shorted

PCM has an internal feedback to monitor state of by-pass circuit. Code 42 will set if by-pass circuit is open or shorted to ground at time of engine start-up. If Code 41 is set with Code 42, use CODES 41 & 42 SIMULTANEOUS chart.

Fig 1: Code 42 Schematic (Saturn) By-Pass Open Or Shorted

Fig 2: Code 42 Flow Chart (Saturn) By-Pass Open Or Shorted