With 4 Wheel Drive

Code 24 Vehicle Speed Sensor Circuit Fault (4WD):

Wiring Diagram For Code 24 Vehicle Speed Sensor Circuit Fault (4WD):

CODE 24 - VSS CIRCUIT FAULT


CIRCUIT DESCRIPTION:

The output sensor circuit is the magnetic induction type. Gear teeth pressed in the outside diameter of the output carrier assembly induce an alternating current in the sensor. Since the vehicle speed is taken from the transfer case on four wheel drive vehicles, the transmission output speed sensor signal on these units goes directly to the PCM. Code 24 will set when engine speed is above 3000 rpm and output speed sensor reading is below 200 rpm for 1.5 seconds, Park/Neutral not selected.




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

1. Test one verifies a vehicle speed sensor voltage at the PCM.

2. Test two directly verifies the operation of the vehicle speed sensor.





DIAGNOSTIC AIDS:

Check all connections especially those at the transmission pass-thru connector. If the input speed sensor is not functioning at start up, it will cause the vehicle speed sensor to read zero.