IDLER GP 5552673 - Caterpillar

Introduction
The implement/swing pressure switch is normally OFF until an implement or swing circuit is used. With the AEC (automatic engine control) ON, activation of the implement/swing circuit closes the pressure switch to turn the AEC OFF so engine speed can increase. This test will determine a cause for a malfunction in the implement/swing pressure switch circuit. 1. Using the "Digital Input", check the operation of implement/swing pressure switch.a. Start the engine.b. Select the "Digital Input" function mode labeled "E" in the Data Mode Controller Service Program for checking the implement/swing pressure switch. Refer to, "Service Operations, Data Mode" Form SENR6155.c. Alternately move the bucket pilot control lever to the bucket OPEN and NEUTRAL positions.d. Check the Digital Input display. Expected Result:When the bucket pilot control lever is moved to the bucket OPEN position, the Digital Input display should show [EOn]. When the bucket pilot control lever is moved to the NEUTRAL position, the Digital Input display should show [EoF]. Results:* YES - STOP.* NO - Proceed to Step 2.2. Check machine harness connectors.Check connectors in machine harness between the controller and the implement/swing pressure switch and between frame ground and the implement/swing pressure switch for being loose or corroded. Results:* OK - Proceed to Step 3.* NOT OK - Repair connectors. If conditions are not resolved, proceed to Step 3.3. Check the implement/swing pressure switch.
Main Control Valve
(1) Pressure switch (implement/swing). (2) Connector.a. Disconnect machine harness from implement/swing pressure switch (1) at connector (2).b. Start the engine.c. Check continuity between the connectors of the implement pressure switch while the bucket pilot control lever in the OPEN and NEUTRAL positions. Expected Result:There is continuity when the bucket pilot control lever is in the OPEN position. There is no continuity when the bucket pilot control lever is in NEUTRAL. Results:* OK - Proceed to Step 4.* NOT OK - Proceed to Step 5.4. Check implement/swing pressure switch circuit for an open.a. Turn disconnect switch and key start switch OFF.b. Disconnect the 24 contact connector machine harness from the controller.c. At the pressure switch end of the machine harness, short connector contact 1 (A771-PU) to 2 (200-BK) with a jumper cable.d. At the 24 connector contact check for continuity between connector contact 17 and frame ground.Reference: Refer to SENR6183 for additional information. Expected Result:There should be continuity between connector contact 17 and frame ground. Results:* OK - Proceed to Step 6.* NOT OK - Harness has an open. Repair or replace machine harness between controller and implement pressure switch. STOP.5. Check pilot signal pressure at the implement pressure switch.a. Stop the engine and release the pressure in the hydraulic system. Refer to "Release Of Pressure In The Hydraulic System", Form SENR6187.b. Install a tee and a 4000 kPa (580 psi) gauge at implement pressure switch (1) connection to the main control valve.c. Start the engine.d. Move the bucket pilot control lever to the OPEN or CLOSED position.e. Check pressure at the implement pressure switch.f. Return the bucket pilot control lever to the