Diagnostic Aids

A faulty or misadjusted park/neutral switch may set a false Code 24. Use scan tester to check for proper signal in Drive while wiggling shifter. Code 24 may set if vehicle is power braked (brakes applied and throttle depressed) for more than 10 seconds. Check circuits No. 400 and 401 for proper connections.

Fig 1: Code 24, Schematic, Vehicle Speed Sensor (VSS) 3.8L

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 24, Flow Chart, Vehicle Speed Sensor (VSS) 3.8L

Courtesy of GENERAL MOTORS CORP.