BEARING-INNER 4B8108 - Caterpillar

System Operation Description:Use the following procedure to troubleshoot the electrical system if a problem is suspected with the switch circuits or if another procedure has sent you here.The following switches may be used:
Maintenance clear switch
Torque limit switch
Ether starting aid switch
PTO interrupt switch
Remote shutdown switch
Intermediate engine speed switch
Overspeed verify switch
PTO enable switch
PTO ramp up switch
PTO set switch
PTO ramp down switch
PTO resume switchSwitch circuits may have problems such as faulty wiring, faulty switches, or faulty connectors.The switches are normally open or normally closed.
Illustration 1 g01383764
Schematic for the normally open switch and the normally closed switch
Typical switch inputs
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Check the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01388291
Left side view
(1) J1/P1Electronic Control Module (ECM) connectors
Thoroughly inspect the J1/P1 connectors. Thoroughly inspect the connections for the suspect switch. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01383775
P1 terminals for the various switches
(P1-6) Maintenance clear switch
(P1-7) Torque limit switch
(P1-22) Ether starting aid switch
(P1-41) PTO interrupt switch
(P1-44) Remote shutdown switch
(P1-45) Intermediate engine speed switch
(P1-54) Overspeed verify switch
(P1-56) PTO enable switch
(P1-58) PTO ramp up switch or set switch
(P1-60) PTO ramp down switch or resume switch
Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the suspect switch.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The wiring and connectors are OK. Proceed to Test Step 2.
Not OK - There is a problem with the wiring and/or a connector.Repair: Repair the wiring and/or the connector. Replace parts, if necessary. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 2. Test the Switch for Proper Operation
Disconnect the J1/P1 connector.
Refer to Table 1. Determine the P1 terminal for the suspect switch.
Table 1
Terminals for the Switch Inputs
Name of the Switch P1 Terminals J61/P61 Terminals
Maintenance clear switch 6 12
Torque limit switch 7 2
Ether starting aid switch 22 38
PTO interrupt switch 41 19
Remote shutdown switch 44 27
Intermediate engine speed switch 45 28
Overspeed verify switch 54 40
PTO enable switch 56 29
PTO ramp up switch or set switch 58 30
PTO ramp down switch or resume switch 60 39
Connect a meter lead to the P1 terminal for the suspect switch. Connect the other meter lead to engine ground. Note: Wiggle the harnesses during the following measurements in order to reveal any intermittent short