BUSHING-REDUCER 7B2176 - Caterpillar

System Operation Description:The ECM has the ability to crank the engine when the ECS is placed in the START position. The engine control will start the first crank cycle, when the ECS is placed in the START position. The crank cycle will continue for the time that is equal to the cycle crank time that has been programmed or the crank cycle will continue until the engine speed reaches the crank terminate speed. If crank terminate speed is not reached before the cycle crank time, the starting motor will deactivate for a time that is equal to the cycle crank time.This process will repeat for a programmed amount of times (Total Number of Crank Cycles). If the engine does not start the starter mode on the Electronic Service Tool will display "OVERCRANK". The engine control will be in an idle state. The process can be restarted by turning the ECS to the OFF/RESET. Next turn the ECS to the STOP position. Then turn the ECS to the START position.Note: If you are troubleshooting a system that has EMCP II, this function will be performed by the control panel. Refer to the Service Manual, SENR5398.
Illustration 1 g00598835
SchematicTest Step 1. Check for connector damage.
Verify that the circuit breakers are not tripped.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Check connectors and wiring for the following problems: damage, corrosion, abrasion and incorrect attachment.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - Proceed to test step 2.
Not OK - Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. Stop.Test Step 2. Check the ECS.
Verify proper operation of the ECS.Expected Result:Results:
OK - The ECS is working correctly. Proceed to test step 3.
Not OK - A problem was found with the ECS.Repair: Repair the ECS and/or replace the ECS. Stop.Test Step 3. Attempt To Start the Engine
Turn the circuit breaker for the battery to the ON position.
Turn the ECS to the STOP position.
Connect an Electronic Service Tool to the Service Tool Connector.
Observe the startup mode parameter on the Electronic Service Tool status screen.
Turn the ECS to the START position. Monitor the startup mode parameter.
The crank cycle will continue for the time that is equal to the cycle crank time that has been programmed or the crank cycle will continue until the engine speed reaches the crank terminate speed.Expected Result:The status screen for the startup mode parameter should display "CRANK".Results:
OK - The startup mode parameter on the status screen on the Electronic Service Tool displays "CRANK". Stop.
Not OK - The engine will not crank. Proceed to test step 4.Test Step 4. Manually Crank The Engine.
Turn the ECS to the START position.
Open the Electronic Instrument Panel. Activate the manual crank switch. Listen for the mag relay to activate.Expected Result:The mag relay should activate and the starting solenoid should activate.Results:
OK - The relay activates and the engine starts. Proceed to test step 5.
Relay(s) Active - The relay