VALVE GP 1172989 - Caterpillar

Illustration 1 g01264891
C15 schematic
Illustration 2 g01261068
C11 schematic
Illustration 3 g01261336
P1 ECM connections (P1-48) +Battery (P1-52) +Battery (P1-63) −Battery (P1-61) −Battery (P1-70) KeyswitchTest Step 1. Inspect Electrical Connectors and Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points. All connections and grounds are tight and free of corrosion.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Battery Voltage at the ECM
Disconnect the J1/P1 ECM connector.
Restore the electrical power to the ECM.
Measure the voltage between P1-48 (Switched Positive Battery) and P1-63 (Negative Battery).
Measure the voltage between P1-52 (Switched Positive Battery) and P1-61 (Negative Battery).
Measure the voltage between P1-70 (Keyswitch) and P1-63 (Negative Battery).Expected Result:The voltage measures 24 3.0 VDC.Results:
OK - The ECM is receiving the correct voltage.Repair: If an intermittent condition is suspected, refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The voltage is not correct at the ECM. Proceed to Test Step 3.
Not OK - Keyswitch - The voltage is not correct at the input for the keyswitch. Proceed to Test Step 4.Test Step 3. Check the Batteries
Measure the no-load battery voltage at the battery posts.
Load test the batteries. Use the 4C-4911 Battery Load Tester. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6, 8 and 12 Volt Lead Acid Batteries" and Special Instruction, SEHS7633, "Battery Test Procedure".Expected Result:The batteries pass the load test. The measured voltage is the minimum specification for a 12V or 24V system.Results:
OK - The batteries are OK. Proceed to Test Step 4.
Not OK - The battery voltage is low or the battery did not pass the load test.Repair: Recharge or replace the faulty batteries. Verify that the repair eliminates the problem.STOPTest Step 4. Check the Voltage from the Keyswitch
Remove the electrical power from the ECM.
Remove the wire from terminal R of the keyswitch.
Restore the electrical power to the ECM.
Turn the keyswitch to the ON position.
Measure the voltage between terminal B of the keyswitch and engine ground.
Measure the voltage between terminal R of the keyswitch and engine ground.
Turn the keyswitch to the OFF position.
Remove the electrical power from the ECM.
Reconnect all wires to the original configuration.Expected Result:Voltage