CANOPY GP-OPEN ROPS 3822207 - Caterpillar

Illustration 1 g02042997
Schematic of the switch for service door on the rotorThis switch (sensor) has two inputs to the ECM. During normal operation, one of the inputs is open and the other input is grounded. The preceding chart shows the continuity of each switch circuit for the two positions of the switch. When a circuit is measured with a voltmeter, an open circuit will measure 5 DCV and a returned circuit will measure approximately 0 DCV. A failure is detected when the status of the inputs are in the following conditions:
Both the switch inputs are open.
Both the switch inputs are grounded.Power is provided to the proximity switch from the circuit (wire 119-PK).This diagnostic code is recorded when both of the inputs are open or grounded. The possible causes of this failure are listed below:
The return circuit (wire 229-BK) is open.
The battery circuit (wire 119-PK) is open.
The signal circuit (wire L930-GN) is open.
The signal circuit (wire C724-OR) is open.
The signal circuit (wire L930-GN) is grounded.
The signal circuit (wire C724-OR) is grounded.
The rotor door switch is faulty.
The ECM has failed. This is unlikely.System Response:The machine response is listed below:
A Category 2 warning is showing on the Computerized Monitoring System (CMS).
The steering, propulsion and rotor control are disabled. The functions will not be returned until the fault is no longer present. Note: Ensure that the diagnostic code of CID 748 FMI 02 is active before performing this procedure. If the diagnostic code CID 748 FMI 02 is not active, toggle the switch until the diagnostic code CID 748 FMI 02 is active. Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.Test Step 1. CHECK THE OPERATION OF THE SWITCH (SENSOR)This step uses the indicator on the sensor to check for power and ground to the sensor.
Turn the key start switch to the ON position.
While the indicator on the back of the sensor is observed, place a metal object directly in front of the sensor.Expected Result:When the metal object is in front of the sensor the indicator must be ON position. When the metal object is removed, the indicator must be OFF position. Results:
OK - Proceed to Test Step 3.
NOT OK - The sensor or the machine harness is faulty. Proceed to Test Step 2.Test Step 2. CHECK THE POWER AND RETURN CIRCUITS OF SENSORThis step determines whether the switch or the machine harness is faulty.
Turn the key start switch to the ON position.
Disconnect the sensor connector.
Check for +battery voltage from contact 3 to return contact 1 on the machine harness connector for the sensor.Expected Result:The voltage that is measured should be approximately +battery.Results:
OK - The sensor is faulty.Repair: Replace the sensor.STOP
NOT OK - The machine harness is faulty. Either the +Battery circuit (wire 119-PK) or the return circuit (wire 229-BK) is open in the machine harness. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE SIGNAL CIRCUIT FOR PROPER OPERATIONThis step checks the continuity of wire (L930-GN) in the machine harness and through the