Firebird V8-305 5.0L VIN E (1992)
Vehicle Speed Sensor Test
Test E Speedometers and/or Odometer(S) Are Inaccurate
TEST E: SPEEDOMETER IS INACCURATE
1. Plug a Tech 1 scan tool into the ALDL Connector at lower left of lip near steering column. With scan tool on and set to proper mode (RPM/Speed),
operate vehicle at constant speeds. Observe the speedometer and scan tool display.
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If they are in agreement + 2 mph, the Speedometer is good. Check for correct tire size and inflation, and axle ratio gear calibration
If all are correct, replace the VSS Buffer.
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If scan tool and speedometer are not in agreement + 2 mph, go to Step 2.
2. Remove I/P Cluster. Connect a J 33431-B Signal Generator and instrument Panel Tester to printed circuit on underside of lip Cluster using a J
33431-9 Speedometer Edgeboard Connector. With the tester plugged in and set to ON, 54 mph, and 60 Hz, the Speedometer should read 54 mph + 2
mph.
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If the Speedometer does not indicate properly, the Speedometer is to be sent to an approved A/C Repair Center for repair.
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if the Speedometer operates properly, replace the VSS Buffer.
Test F Odometer(S) Are Inoperative or Inaccurate
TEST F: ODOMETER(S) DO NOT OPERATE CORRECTLY
1. Remove the I/P Cluster. Disassemble the cluster and remove the small Odometer connectors from the Speedometer circuit board. Connect a J
33431-3 Odometer Motor Test Harness. Plug in the lip tester and set it to ON, 54 mph, and 60 Hz. With the Odometer test switch held down, the
Odometer should turn and change the mileage shown, about 1.8 miles per minute.
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If the Odometer does not turn, replace the stepper motor