ORIFICE-VALVE 4J6803 - Caterpillar

Illustration 1 g03051016
Schematic of the Inter Axle Lock Accumulator Pressure SensorThis diagnostic code is associated with the pressure sensor for the Inter Axle Lock Accumulator Pressure Sensor. The sensor provides a PWM signal to the Chassis ECM. The pressure sensor outputs a frequency of 500 100 Hz, and the duty cycle between 3% to 97%. The Inter Axle Lock Accumulator Pressure Sensor measures the pressure in the Inter Axle Lock system. Based on the measured pressure, ATC will turn ON or OFF the Inter Axle Lock Charge Pressure Solenoid.The output frequency of the sensor is 500 100 Hz. The duty cycle of the signal is proportional to the pressure that is applied. The duty cycle varies from 3% to 97%.The possible causes of this diagnostic code are listed below:
The power circuit or the ground circuit has failed.
The sensor has failed.
The signal circuit for the sensor is open.
The harness of the circuit has failed.
The Chassis ECM has failed. This situation is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 3542 FMI 08 is active before performing this procedure.Note: Use a calibrated 146-4080 Digital Multimeter for the measurements in this procedure. System Response:
ATC is not available
ATC will disable the Inter Axle Lock Accumulator Charge Solenoid and the Inter Axle Lock Solenoid
ATC lamp on the main cluster display will flash when the fault is active and a warning message will pop up on the CMPD. Test Step 1. CHECK FOR FREQUENCY OUTPUT AT THE SENSOR.
At the back of the harness connector for the sensor, remove the 7X-1710 Multimeter Probe from (contact .1).
Insert the 7X-1710 Multimeter Probe along the signal wire (contact 3).
At the back of the harness connector for the sensor, do not remove the inserted 7X-1710 Multimeter Probe along the ground wire (contact 2)
Turn the disconnect switch and the key start switch to the ON position.
Monitor the frequency signal and the duty cycle signal of the sensor with the 146-4080 Digital Multimeter .Expected Result:The Digital Multimeter reads the frequency value of 500 100 Hz and the duty cycle value between 3% to 97%.Results:
OK - The frequency is 500 100 Hz and the duty cycle value is between 3% to 97%. The sensor is operating correctly. The FMI 8 fault should not activate.STOP
NOT OK - The sensor signal does not output the correct frequency or duty cycle range. The sensor is not operating correctly or may have failed.Repair: Replace the sensor.STOP