Code 24, Vehicle Speed Sensor (A, F, J, L, N, W & Y Bodies): Notes

Fig 1: Code 24, VSS Circuit Diagram 1 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 2: Code 24, VSS Circuit Diagram 2 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 3: Code 24, VSS Circuit Diagram 3 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 4: Code 24, VSS Circuit Diagram 4 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 5: Code 24, VSS Circuit Diagram 5 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 6: Code 24, VSS Circuit Diagram 6 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 7: Code 24, VSS Circuit Diagram 7 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 8: Code 24, VSS Circuit Diagram 8 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 9: Code 24, VSS Circuit Diagram 9 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 10: Code 24, VSS Circuit Diagram 10 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 11: Code 24, VSS Circuit Diagram 11 Of 12 (A, F, J, L, N, W & Y Bodies)

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Fig 12: Code 24, VSS Circuit Diagram 12 Of 12 (A, F, J, L, N, W & Y Bodies)

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The speed sensor, which is a Permanent Magnet (PM) generator, provides the control module with vehicle speed information. The PM generator, mounted on the transmission, produces a pulsing voltage signal whenever the vehicle speed is more than 3 MPH. The voltage level and pulses increase with vehicle speed. The control module converts the pulsing voltage to MPH, which is used by the control module in calculations to determine vehicle adjustments.

NOTE: Test numbers refer to test numbers on diagnostic chart.

A Code 24 will set when MPH reads zero, transmission is not in Park or Neutral, engine speed indicates vehicle is in a cruise mode (1200-4400) RPM, TPS indicates closed throttle and high manifold vacuum is sensed by the MAP sensor. All of these conditions must be met for 2-5 seconds. The PM generator only produces a voltage signal if drive wheels are turning greater than 3 MPH.
Before replacing the control module, PROM/MEM-CAL should be checked for correct application.