CODE 24, VEHICLE SPEED SENSOR
Speed sensor, which is a Permanent Magnet (PM) generator, provides control module with vehicle speed information. PM generator, mounted in transmission, produces a pulsing AC voltage signal whenever vehicle speed is greater than about 2 MPH. Voltage level and pulses increase with vehicle speed. Control module converts pulsing voltage to MPH, which is used by control module to calculate vehicle adjustments.
Note. Test numbers refer to numbers on diagnostic chart.
Note. Prior to testing Corvette for Code 24, disable ASR system.
- PM generator only produces a voltage signal if drive wheels are turning greater than about 2 MPH.
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.