October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Diagnostic Aids

The scan tester cannot help diagnose a Code 42 problem. See INTERMITTENTS in TESTS W/O CODES article in this section.

Fig 1: CODE 42, Schematic, Elec. Spark Timing (V8 C, K & P Series W/ M/T)

Fig 2: CODE 42, Schematic, Elec. Spark Timing (All Models W/ 4L60E Trans. Exc. CPI)

Fig 3: CODE 42, Schematic, Elec. Spark Timing (All W/ 4L60E Trans. & CPI)

Fig 4: CODE 42, Schematic, Elec. Spark Timing (All W/ 4L80E Trans.)

Fig 5: CODE 42, Flowchart, Elec. Spark Timing