CARBODY AS 4E6778 - Caterpillar

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Typical example
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P1 ECM connector
(P1-10) Desired fuel
(P1-05) Digital return
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Customer connector
(Terminal BN) Desired fuel
(Terminal AP) - 0-200 ma
(Terminal t) + 0-200 ma
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Location of ECM connectors
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the Engine Control Switch (ECS) to the OFF/RESET position.
Turn the battery disconnect switch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" 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 allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" 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 coupled and/or inserted. 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 - The connectors and/or wiring are not OK.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Current Input to the Signal Converter
Measure the current to the signal converter. Note: Some external governors may only be able to output approximately 150 mA. This should not be seen as a problem with the external governor.Expected Result:The current range is between 0 and 200 mA.Results:
OK - The current is within the correct range. Proceed to Test Step 3.
Not OK - The current is not within the correct range.Repair: Replace the external governor that is supplying the controlling current.STOPTest Step 3. Check the Voltage at the Battery
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET 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 batteries. Use the 4C-4911 Battery Load Tester. Refer to the Operating Manual, SEHS9249. Refer to Special Instruction, SEHS7633. Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage measures 24 3 VDC. Proceed to Test Step 4.
Not OK - The voltage is not 24 3 VDC.Repair: The batteries or the alternator are causing the problem. Recharge the batteries or replace the batteries. Verify that the original condition is resolved. Refer to Testing and Adjusting, "Electrical System".STOPTest Step 4. Check the Voltage at the Signal Converter
Connect one probe of the voltmeter to the +Battery terminal at the signal converter.
Connect one probe of the voltmeter to the digital return terminal at the signal converter. Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. Proceed to Test Step 5.
Not OK - The voltage is not 24 3 VDC.Repair: Check the wiring and/or the connectors that are between the battery and the signal converter. Repair the wiring and/or connectors.STOPTest Step 5. Check the Throttle Position
Connect the