Diagnostic Aids

Check all connections, especially those at transmission pass-through connector. If code is intermittent, see INTERMITTENTS in TESTS W/O CODES article in this section. While Code 24 is set, scan tester will display an RPM derived from input speed. If input speed sensor is not operational at start-up, this can cause VSS to read zero.

Fig 1: CODE 24, Schematic, VSS (4.3L S & T Series P/U W/ M/T Exc. Turbo)

Fig 2: CODE 24, Schematic, VSS (4WD W/ 4L80E Transmission)

Fig 3: CODE 24, Flowchart, VSS (4.3L S & T W/ M/T & 4WD W/ 4L80E Trans.)