Diagnostic Aids

The "Scan" tester does not have the ability to help diagnosis Code 42 problems. If Code 42 is intermittent, see INTERMITTENTS in TESTS W/O CODES article.

Fig 1: Code 42, Circuit Wiring Diagram

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 42, Flow Chart

Courtesy of GENERAL MOTORS CORP.