DTC 24

Code Chart 24:

VSS Wiring Circuit:

CIRCUIT DESCRIPTION:
Vehicle speed information is provided to the Electronic Control Module (ECM) by the Vehicle Speed Sensor (VSS) which is a Permanent Magnet (PM) Generator and it is mounted in the transaxle. The PM generator produces a pulsing voltage whenever vehicle speed is over about 3 mph. The AC voltage level and the number of pulses increases with vehicle speed. The ECM then converts the pulsing voltage to mph which is used for calculations and the mph can be displayed with a "Scan" tool.

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. Code 24 will set if vehicle speed equals 0 mph when:

^ Engine speed is between 2200 and 4400 rpm
^ Throttle Position Sensor (TPS) is less than 2%
^ Low load condition (Low Air Flow)
^ Not in park or neutral
^ All conditions met for 5 seconds.
These conditions are met during a road load deceleration. Disregard Code 24 that sets when drive wheels are not turning.
^ The PM Generator only produces a signal if drive wheels are turning greater than 3 mph.

DIAGNOSTIC AIDS:
^ "Scan" should indicate a vehicle speed whenever the drive wheels are turning greater than 3 mph. A problem in CKT 381 will not affect the VSS input or the readings on a "Scan."
^ Check CKT 400 and 401 for proper connections to be sure there clean and tight and the harness is routed correctly. - Intermittent Malfunctions
^ A faulty or misadjusted Park/Neutral switch can result in a false Code 24. Use a "Scan" and check for proper signal while in drive. For P/N switch diagnosis check, Chart C-1A Park/Neutral Switch Diagnosis