With PFI

Fig. 029 - Chart - Code 24 Vehicle Speed Sensor - Buffer Attached To I.P. Cluster:

Fig. 031 - WIRING DIAGRAM for Code 24 Vehicle Speed Sensor - Integral Buffer. VIN J:

CODE 24

VSS (INTEGRAL BUFFER)
1.8L TURBO "J" SERIES

FUEL INJECTION (PORT)

The ECM supplies a current limited 12 volt signal on CKT 437. The VSS located in the I.P. cluster will sense the speedometer rotating element and furnish this information to the buffer as a "Pulsed" signal, 2 per cable revolutions of 2002 per mile.
The buffer assembly will switch CKT 437 to ground for each pulse recieved. The ECM uses the time between pulses to dedermine vehcle speed.
Code 24 is set by the following:
a. CKT 437 voltage is constant. No rise and fall of voltage for a specified time, 4 to 10 seconds.
b. Engine speed between 1500 and 4400 RPM.
c. Park/Neutral switch indicates transmission selector is in drive range.
d. Low MAP (High Vacuum) indicating an engine decel.
Loss of VSS will effect:
a. Torque Converter Clutch
b. Idle Air Control
c. Fan Control will not shut off above 30 MPH (48 Km/h)with A/C on.
1. Checks to see if there is a VSS signal to the ECM while turning a drive wheel. Normally voltage will vary from under 3 volts to over 6 volts as wheel is turned slowly. The faster the wheel is turned, the less the variation.