ENGINE AR-CORE 2655308 - Caterpillar

System Operation Description:The engine has two Electronic Control Modules (ECM). The Secondary ECM controls power to the backup Engine Speed/Timing sensor. The Secondary ECM also controls the air shutoff relay. All other engine functions are controlled by the Primary ECM.When power is applied to the system, the Secondary ECM will illuminate the Ready Lamp for 5 seconds. When the Secondary ECM assumes engine control, the Active Lamp will illuminate.Note: Refer to Troubleshooting, "ECM/Personality Module".The Primary ECM controls the engine:
Engine speed
Governing
Engine monitoringThe Secondary ECM will take control due to the following reasons:
Loss of the Primary ECM heartbeat signal
Two injector faults for the 12 cylinder engineThe Primary ECM also communicates some information to the display.The Secondary ECM provides governing if the Primary ECM fails. If this occurs, the Secondary ECM automatically assumes engine control.Note: The Secondary ECM is not a fully functional ECM. The Secondary ECM is used to keep the engine running until the vessel can obtain proper service. The Secondary ECM is used to control the governing of the engine.
Illustration 1 g00809763
Note: The Engine Control Switch (ECS) is mounted within an instrument panel that is located on the right side of the engine. The ECS is locked into the AUTO position with a pin. The pin must be removed in order to perform this test. After performing this test, ensure that the ECS is placed in the AUTO position and that the locking pin has been reinstalled.Test Step 1. Check for Connector Damage.
Turn the ECS to the OFF/RESET position.
Disconnect the main power.
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 ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring should be free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are okay. Proceed to test step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check the Active Lamp and the Ready Lamp for the Secondary ECM.
Observe the Active lamp and the Ready lamp on the instrument panel when the ECS is turned to the STOP position.Expected Result:Both lamps should illuminate for five seconds. The Ready Lamp should remain illuminated. The Active lamp should illuminate for five seconds. The Active lamp should then turn off.Results:
OK - Both lamps illuminated for five seconds. The Ready Lamp remained illuminated. The Active Lamp is off. The problem is no longer present.Repair: The secondary ECM reads the primary ECM heartbeat signal.