PLATE AS 4781759 - Caterpillar

the system and note any active diagnostic codes.STOPTest Step 11. Compare the Pressure or Temperature to the Actual Pressure or Temperature
Turn the keyswitch to the OFF position.
If you are troubleshooting a temperature sensor, install a 6V-9130 Temperature Adapter near the sensor.
Turn the keyswitch to the ON position. The engine should be off.
Observe the temperature reading for the sensor. Cat ET should display the same temperature as the 6V-9130 Temperature Adapter .Note: When the temperature is below 0 °C (32 °F), the temperature can vary 15 °C (59 °F).
If you are troubleshooting a pressure sensor, disconnect the sensor.
Remove the sensor from the engine.
Reconnect the sensor.
Connect the vacuum pump test unit to the sensor.
Connect the vacuum pump to the differential pressure gauge.
Turn the keyswitch to the ON position. The engine should be off.
Observe the pressure reading for the sensor. Cat ET should display the barometric pressure in your area.
Use the vacuum pump to pull 5 kPa (0.5 psi) of vacuum on the differential pressure gauge.Note: The pressure gauge reading should remain constant until the vacuum is released.
Compare the readings on the Cat ET and the pressure test kit.Expected Result:The Cat ET shows a constant pressure. The Cat ET shows a 5 2 kPa (0.5 0.3 psi) drop in pressure.Results:
OK - Cat ET shows a constant pressure. Cat ET shows a 5 2 kPa (0.5 0.3 psi) drop in pressure.Repair: The sensor is working correctly. Reset the system and note any active diagnostic codes. STOP
Not OK Analog - Cat ET does not show a constant pressure. Cat ET does not show a 5 2 kPa (0.5 0.3 psi) drop in pressure. The analog sensor is not producing the correct reading. Proceed to Test Step 12.
Not OK Digital - Cat ET does not show a constant pressure. Cat ET does not show a 5 2 kPa (0.5 0.3 psi) drop in pressure. The digital sensor is not producing the correct reading. Proceed to Test Step 13.
Vacuum Leak - Cat ET does not show a constant pressure. Cat ET does not show a 5 2 kPa (0.5 0.3 psi) drop in pressure. A vacuum leak is suspected.Repair: Check for leaks. If no leaks are found, there may be an internal leak in the pressure sensor. Replace the sensor and calibrate the sensor. Reset the system and note any active diagnostic codes.STOPTest Step 12. Check the Analog Sensor's Signal Voltage at the Connector
Turn the keyswitch to the ON position. The engine should be off.
Measure the sensor signal voltage between terminal C and terminal B at the suspect sensor's connector.Expected Result:The sensor signal voltage is between 0.2 VDC and 4.8 VDC for analog sensors.Results:
OK - The sensor signal voltage is between 0.2 VDC and 4.8 VDC for analog sensors. The signal voltage is correct. Proceed to Test Step 16.
Not OK - The sensor signal voltage is not between 0.2 VDC and 4.8 VDC for analog sensors. The signal voltage is not correct. Proceed to Test