FITTING 3B7264 - Caterpillar

System Operation Description:The Electronic Control Module (ECM) receives electrical power through the customer connector (J14/P14). Typically, the ECM is powered whenever the engine control switch is turned to the ON position. Aftermarket engine protection devices are often wired in order to interrupt supply voltage to the ECM. Check for proper installation and operation of the engine protection devices.Use this test if there are intermittent engine shutdowns or if a difficulty in starting is not accompanied by loss of electrical accessories. Engine shutdowns that are accompanied by a loss of other electrical accessories indicate a problem in the keyswitch. This does not indicate a problem in the wiring at the engine's ECM. Verify that there are no problems with the starting system or the charging system before you use this test.
Illustration 1 g01626598
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(1) + Battery (21) - BatteryUse this procedure to troubleshoot the electrical system if a problem is suspected with the power to the engine's Electronic Control Module (ECM) or if the diagnostic code in the Table is active or easily repeated.
Table 1
Diagnostic Code    
Code and Description     Flash Code     Default Conditions which Generate this Code     System Response    
168-02 ECM Battery Power Intermittent     51     Battery voltage at the ECM is less than 7 VDC.     The code is logged.    Test Step 1. Inspect the Electrical Connectors and the Wiring Harness
Remove electrical power from the ECM.
Thoroughly inspect the ECM connector J14/P14. Also, inspect connector J17/P17. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the Power Supply.
Check the allen head screw on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.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 OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or the wiring.Repair: Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.Verify that the repair eliminates the problem.STOPTest Step 2. Check Battery Voltage at the Battery
Turn the engine control switch to the OFF position.
Turn the circuit breaker for the battery to the OFF position.
Measure no-load battery voltage at the battery terminals. Refer to Testing and Adjusting, "Test Tools for the Electrical System" for the proper procedures to check the batteries.
Load test the battery. Use the 4C-4911 Battery Load Tester .Expected Result:The no-load voltage at the batteries is at least 23.5 VDC and the batteries pass the load test.Results:
OK - The no-load voltage at the batteries is at least 23.5 VDC and the batteries pass the load test. Proceed to Test Step 3.
Not OK - The no-load voltage at the batteries is less than 23.5 VDC, and/or the