3412 Generator Set Caterpillar

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 ECM. Verify that there are no problems with the starting system or the charging system before you use this test.

Illustration 1	g03842466

Table 1

Code and Description	Default Conditions which Generate this Code	System Response
168-02 ECM Battery Power Intermittent	Battery voltage at the ECM is less than 7 VDC.	The code is logged.
168-03 ECM Battery Power Input #1 voltage above normal	Battery voltage is out of normal operating range - high	The code is logged.
168-04 ECM Battery Power Input #1 voltage below normal	Battery voltage is out of normal operating range - low	The code is logged.

Recommended Actions

Table 2

Troubleshooting Test Steps	Value	Results
1. Inspect the Electrical Connectors and the Wiring Harness. A. Remove electrical power from the ECM. B. Inspect the ECM connector J1/P1. Also, inspect connector J17/P17. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the Power Supply. D. Check the allen head screw on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.	Electrical connectors and/or wiring	Result : The electrical connectors and/or wiring is OK. Proceed Test Step 2. Result : The electrical connectors and/or wiring is NOT OK. 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. If the problem is not resolved, proceed to Test Step 2.
2. Check Battery Voltage at the Battery. A. Turn the engine control switch to the OFF position. B. Turn the circuit breaker for the battery to the OFF position. C. 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. D. Load test the battery. Use the 4C-4911 Battery Load Tester.	Battery voltage	Result : The battery voltage is OK. Proceed to Test Step 2. Result : The battery voltage is NOT OK. Repair : The batteries or the alternator are causing the problem. Recharge the batteries or replace the batteries. Refer to Systems Operation/Testing and Adjusting. If the problem is not resolved, proceed to Test Step 3.
3. Check the Voltage to the ECM. A. Disconnect the ECM connector J1/P1. B. Turn the circuit breaker for the battery to the ON position. C. urn the engine control switch to the ON position. D. Measure the voltage between the following pins. - P1-84 and P1-81 - P17-19 and P17-13	Voltage	Result : The voltage is OK. Repair : The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect". If the problem is not resolved, proceed to Test Step 4. Result : The voltage is NOT OK. Proceed to Test Step 4.
4. Check Voltage at the Circuit Breaker. A. Turn the circuit breaker for the battery to the ON position. B. Turn the engine control switch to the ON position. C. Measure voltage from both terminals of the breaker to engine ground.	Voltage	Result : The voltage is OK. Repair : The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect". Result : The voltage is NOT OK. Repair : The fuse or the breaker is in need of repair or replacement.