PLATE 2S6949 - Caterpillar

Illustration 2 g01395011
Terminal locations of the connectors for the fuse block assemblyTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the battery disconnect switch to the OFF position.
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J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connectors. Inspect all of the connectors that are in the circuit. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
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P1 connections for the electrical power supply circuit (P1-48) +Battery (P1-52) +Battery (P1-53) +Battery (P1-55) +Battery (P1-61) −Battery (P1-63) −Battery (P1-65) −Battery (P1-67) −Battery (P1-70) Keyswitch
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 allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
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 appear to be 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.
Turn the battery disconnect switch to the ON position.
Turn the keyswitch to the ON position.
Wiggle the wires in the harness while performing the following test steps.
Measure the voltage between P1-48 (Unswitched +Battery) and P1-61 (−Battery).
Measure the voltage between P1-52 (Unswitched +Battery) and P1-63 (−Battery).
Measure the voltage between P1-53 (Unswitched +Battery) and P1-65 (−Battery).
Measure the voltage between P1-55 (Unswitched +Battery) and P1-67 (−Battery).
Measure the voltage between P1-70 (Keyswitch) and P1-63 (−Battery).Expected Result:The measured voltage is between 22 VDC and 27 VDC.Results:
OK - The ECM is receiving the correct voltage.Repair: There may be an intermittent electrical problem in a harness or in a connector. If an intermittent condition is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - Unswitched power out of range - The voltage is not correct for one of the unswitched battery circuits at the ECM. Verify that the −Battery connections to the ECM have continuity to the engine ground. If the connections are OK, Proceed to Test Step 3. If the connections are not OK, repair the connectors or wiring and/or replace the connectors or wiring.
Not OK - Keyswitch voltage out of range - The voltage is not correct for the keyswitch circuit at the ECM. Proceed to Test Step 5.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