HOUSING 1931152 - Caterpillar

Illustration 1 g00785407
Schematic of the circuit for the auxiliary hydraulic controlDo NOT start the machine for any of the following Test Steps.Note: After any repair to the auxiliary hydraulic control, cycle the key start switch five times with at least five seconds between cycles in order to reset the calibrations within the auxiliary hydraulic ECM.Test Step 1. CHECK THE DUTY CYCLE OF THE AUXILIARY HYDRAULIC CONTROL
Turn the key start switch to the OFF position.
Remove the access panel for the work tool control.
Locate the connector for the auxiliary hydraulic control beneath the work tool control (joystick).
Connect the 7X-1710 Multimeter Probe to contact 1 (P996-GN) and contact 2 (P997-BR) on the harness side of the connector.
Turn the key start switch to the ON position.Do NOT start the machine.
By using the multimeter, measure the duty cycle of the auxiliary hydraulic control.Note: This measurement is performed without actuating the auxiliary hydraulic control.Expected Result:The duty cycle should be 50% 3%.Results:
OK - The duty cycle is 50% 3%. Proceed to Test Step 5.
NOT OK - The duty cycle is NOT 50% 3%. Proceed to Test Step 2.Test Step 2. CHECK THE CONTINUITY OF THE GROUND CIRCUIT OF THE WIRING HARNESSCheck the resistance from contact 2 (wire P997-BR) to frame ground.Expected Result:The resistance should be less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5 ohms.Repair: The machine harness has an open in wire P997-BR.Repair the wire harness. After the repair, retest the Tests from Test Step 1 if the diagnostic code is still active. Stop.Test Step 3. CHECK THE VOLTAGE OF THE POWER CIRCUIT OF THE WIRING HARNESSCheck the voltage from contact 2 (wire P997-BR) to contact 6 (wire P994-BU).Expected Result:The voltage should be approximately 8 volts.Results:
OK - The voltage is approximately 8 volts. Proceed to Test Step 4.
NOT OK - The voltage is NOT approximately 8 volts.Repair: The machine harness has an open in wire P994-BU.Repair the wire harness. After the repair, retest the Tests from Test Step 1 if the diagnostic code is still active. Stop.Test Step 4. CHECK THE DUTY CYCLE OF THE SIGNAL CIRCUIT FROM THE AUXILIARY HYDRAULIC CONTROL
Turn the key start switch to the OFF position.
Remove the pin (wire P996-GN) from contact 1 of the machine side of the connector.
Connect the 7X-1710 Multimeter Probe to contact 2 (P997-BR) and contact 1 (P996-GN) on the joystick's side of the connector.
Turn the key start switch to the ON position.Do NOT start the machine.
By using the multimeter, measure the duty cycle of the auxiliary hydraulic control.Note: This measurement is performed without actuating the auxiliary hydraulic control.Expected Result:The duty cycle should be 50% 3%.Results:
OK - The duty cycle is 50% 3%.Repair: There is a short in the machine harness between contact 1 (P996-GN) of the connector and contact 53 of the auxiliary hydraulic ECM. Repair the wire harness. After the repair, retest the Tests from Test Step 1 if the diagnostic code is still