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HOMESERVICE MANUALSCHEVROLET1993SPORTVAN G30, VAN PASSENGER, 7.4 NREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 23 (ENGINE CONTROLS - TESTS W/CODES - 6.5L DIESEL)DTC 16 - VEHICLE SPEED SIGNAL BUFFER FAULTNOTES
1993 Chevrolet Sportvan G30, Van Passenger, 7.4 N

DTC 16 - Vehicle Speed Signal Buffer Fault: Notes

1993 Chevrolet Sportvan G30, Van Passenger, 7.4 NSECTION Notes
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 GMC Yukon, 1994 GMC Suburban, 1994 GMC Pickup, 1994 GMC Cab & Chassis, and 1994 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The speed sensor circuit consists of a magnetic induction type sensor, a vehicle speed sensor buffer module and wiring. Gear teeth pressed on the output shaft induce an alternating current in the sensor. This signal is transmitted to the buffer. The buffer compensates for various axle ratios and converts the signal into a square wave for use by the speedometer, cruise control, anti-lock brakes and PCM. The buffer sends 2 different signals to the PCM. The transmission output speed signal circuit relays the transmission output speed which is used to control shift points, line pressure, TCC, DTC 24 and DTC 72. The vehicle speed signal circuit relays the vehicle speed which is used to control engine operating functions and DTC 16. When DTC 24 or 72 is set, second gear only at maximum line pressure will occur. DTC 16 will set when:

  • Vehicle speed greater than 20 MPH.
  • 1000-4400 RPM.
  • Vehicle speed signal circuit is open or grounded.
  • All conditions must be met for 2 seconds.

PCM will default to no cruise control or fuel cutoff.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. This tests for battery voltage at VSS buffer.
  2. This tests for proper ground path for vehicle speed sensor signal buffer.
  3. This tests for vehicle speed sensor signal buffer signal to PCM.
  4. This tests for a signal from VSS buffer to PCM.
RENDER: 1.0x

NO RELATED

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