SEAL-U-CUP 2160008 - Caterpillar

System Operation Description:Switch circuits may have problems such as faulty wiring, faulty switches, or faulty connectors. The least likely cause of a problem with a switch circuit is the Electronic Control Module (ECM). Use the following diagnostic procedures in order to diagnose problems with these switch circuits and repair these switch circuits:
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 switchThe switches are normally open or normally closed.
Illustration 1 g01121934
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
Place the keyswitch in the OFF position.
Illustration 2 g01146374
Engine view (typical example)
(1) J1/P1 ECM connector
Illustration 3 g01146383
Engine view (typical example)
(2) P61 Customer connector
Thoroughly inspect connectors (1) and (2). Thoroughly inspect the connections for the suspect switch. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 4 g01130002
P1 terminals for the various switches
(P1-22) Ether starting aid switch
(P1-23) Maintenance clear switch
(P1-40) Torque limit 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/set switch
(P1-60) PTO ramp down/resume switch
Illustration 5 g01130003
P61/J61 terminals for the various switches
(2) Torque limit switch
(12) Maintenance clear switch
(19) PTO interrupt switch
(27) Remote shutdown switch
(28) Intermediate engine speed switch
(29) PTO enable switch
(30) PTO ramp up/set switch
(38) Ether starting aid switch
(39) PTO ramp down/resume switch
(40) Overspeed verify 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 and the customer connector. 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 and 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 P1 connector.
Refer to Table 1. Determine the P1 terminal for the suspect switch.
Table 1
Terminal Locations for the Switch Inputs
Name of the Switch P1 Terminals J61/P61 Terminals
Ether starting aid switch 22 38
Maintenance clear switch 23 12
Torque limit switch 40 2
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 (set switch) 58 30
PTO ramp down switch (resume switch) 60 39
Use a multimeter to check the resistance of the switch circuits. Connect the meter lead to the P1 terminal for the suspect switch.