ALTERNATOR GP-CHARGING 9N0148 - Caterpillar

Temperature Adapter .
If you are troubleshooting a pressure sensor, disconnect the sensor.
Remove the suspect sensor from the engine.
Reconnect the suspect sensor.
Connect the vacuum pump test unit to the suspect sensor.
Connect the vacuum pump to the differential pressure gauge.
Turn the ECS to the STOP position. The engine should be off.
Observe the pressure reading for the suspect sensor. The Cat ET should display the barometric pressure in your area.
Use the vacuum pump to pull 5 kPa (0.7 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 should show the correct temperature. The Cat ET should show constant pressure. The Cat ET should show a 5 2 kPa (0.7 0.3 psi) drop in pressure when the vacuum is applied.Results:
OK - The correct temperature is shown on the Cat ET. A constant pressure is shown on the Cat ET. A 5 2 kPa (0.7 0.3 psi) drop in pressure is shown on the Cat ET when the vacuum is applied. The sensor is working correctly.Repair: Reset the system and note any active diagnostic codes.STOP
Not OK - Analog - A constant pressure is not shown on the Cat ET. A 5 2 kPa (0.7 0.3 psi) drop in pressure is not shown on the Cat ET while the vacuum is being applied. An analog sensor is not producing the correct reading. Proceed to Test Step 13.
Not OK - Digital - The correct temperature is not shown on the Cat ET. A digital sensor is not producing the correct reading. Proceed to Test Step 14.
Vacuum Leak - A vacuum leak is suspected.Repair: Check for leaks. If no leaks are found, there is an internal leak in the suspect pressure sensor. Replace the sensor and calibrate the sensor. Reset the system and note any active diagnostic codes.STOPTest Step 13. Check the Analog Sensors Signal Voltage at the Sensor Connector.
Turn the ECS to the OFF/RESET position.
Remove the sensors signal wire from pin C of the sensor connector.
Turn the ECS to the STOP position. The engine should be off.
Measure the sensor signal voltage between the sensors