HOSE 4784905 - Caterpillar

Illustration 1 g01092233
Typical schematic
Illustration 2 g00766798
Percent of throttle position versus PWM input
Illustration 3 g01092235
P1 ECM connector
(P1-66) Rated speed signal Test Step 1. Inspect Electrical Connectors and Wiring
Turn the engine control switch (ECS) to the OFF/RESET position.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasions and for pinch points. 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 connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.Repair CompleteTest Step 2. Check the Supply Voltage to the Speed Control
Connect one probe of a voltmeter to the +Battery terminal of the speed control. Connect one probe of the voltmeter to the −Battery terminal of the speed control.
Turn the ECS to the COOLDOWN/STOP position.
Measure the battery voltage at the speed control. Expected Result:The supply voltage is 24 3.0 VDC.Results:
OK - The supply voltage is reaching the speed control. Proceed to Test Step 4.
Not OK - The supply voltage is not reaching the speed control. Proceed to Test Step 3.Test Step 3. Measure the No-Load Battery Voltage
Measure the no-load battery voltage at the battery posts. Note: Load test the batteries by using the 4C-4911 Battery Load Tester. Refer to Special Instruction, SEHS9249, "Use of the 4C-4911 Battery Load Tester" and Special Instruction, SEHS7633, "Battery Test Procedure" for further assistance.Expected Result:The no-load voltage is 22.0 VDC for a 24 Volt system. The batteries pass the load test.Results:
OK - The voltage is in the range at the battery posts. Proceed to Test Step 4.
Not OK - The voltage is out of the range at the battery posts.Repair: The battery voltage is out of the range. Replace the batteries. Verify that the problem is eliminated.STOPTest Step 4. Check the Voltage from the ECS
Turn the ECS to the OFF/RESET position.
Connect one probe of a voltmeter to terminal 10 of the ECS. Connect one probe of the voltmeter to the −Battery terminal.
Turn the ECS to the COOLDOWN/STOP position.
Measure the battery voltage at the ECS.
Turn the ECS to the OFF/RESET position.
Reconnect the signal wire to the customer connector P61-10. Expected Result:The supply voltage is 24 3.0 VDC.Results:
OK - The supply voltage is 24 3.0 VDC.Repair: Verify that the voltage is at GSC relay "RM1". If the voltage is not correct, repair the wire between the GSC and the ECS.If voltage is present at the GSC relay "RM1", verify that voltage is present at GSC relay "RM39". If voltage is present