HARNESS AS-SENSOR 3979338 - Caterpillar

Illustration 1 g01873443
Suspension cylinder pressure sensor circuit
CID 0838 identifies the left front strut pressure sensor. The output frequency of the sensor changes as the pressure in the suspension cylinder changes. The sensor is powered by the machine electrical system.Note: In addition to the “Suspension Cylinder Pressure Sensor” troubleshooting procedure, the VIMSTM diagnostics are helpful in troubleshooting sensors.Use this procedure to troubleshoot the suspect performance of suspension cylinder pressure sensors or any failure that is associated with the suspension cylinder pressure sensors.Note: This test checks for sensor voltages at the sensor when all the circuits are connected. Unless you are directed otherwise, do not disconnect any components. Troubleshoot the circuit “as is” before disconnecting any circuits.
Table 1
Tools Needed
9U-7330 or Equivalent Calibrated Multimeter
7X-1710 Multimeter Probe Before beginning the test procedure:
Locate the suspect sensor.
Identify the sensor wires and connector contacts.
Do not disconnect the harness connectors at this time.
Turn the key start switch to the ON position.
The truck can be empty or the truck can be loaded.Test Step 1. CHECK THE SENSOR SUPPLY VOLTAGE
At the sensor connector, identify:
The +V circuit
The ground circuits
Insert the 7X-1710 Multimeter Probe leads into the back of the connector for the sensor along side of +V and ground circuit wires.
Measure the voltage.Expected Result:The voltage is between 22.0 DCV and 29.5 DCV.Results:
OK - The voltage is between 22.0 DCV and 29.5 DCV. The system voltage is present. Proceed to Test Step 2.
NOT OK - The voltage is less than 22.0 DCV. The circuit is not correct.Repair: Trace the +V and ground circuits in the harness.Repair or replace the harness. Replace the sensor if the harness has not failed.STOPTest Step 2. CHECK THE SENSOR SIGNAL VOLTAGE
At the sensor connector, identify:
The +V circuit
The ground circuits
Insert the 7X-1710 Multimeter Probe leads into the back of the sensor connector (along side of the signal and ground circuit wires).
Measure the signal voltage.Expected Result:The signal voltage is between 1.0 DCV and 9.0 DCV.Results:
The voltage is greater than 9.0 DCV - The signal voltage is not correct. Proceed to Test Step 3.
The voltage is less than 1.0 DCV. - The signal voltage is not correct. Proceed to Test Step 4.
The voltage is between 1.0 DCV and 9.0 DCV - The signal voltage is correct. Proceed to Test Step 5.Test Step 3. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO +BATTERY
Disconnect the sensor from the harness.
At the harness connector