SEAL-RING 6J6553 - Caterpillar

System Operation Description:The electrical power for the engine comes through a 16 amp circuit breaker, the Engine Control Switch (ECS), and the Electronic Control Module (ECM). The system receives battery voltage when the ECS is in the AUTO, START or STOP positions. A signal is provided to the ECM that senses the position of the ECS. When the ECM senses battery voltage on this input, the ECM will power up. If the voltage is removed from the input, the ECM will power down.An emergency stop for engine operation is provided in the starting system. Power to the ECM flows through the breaker for the ECM and the ECM relay. The ECM relay is energized when the ECS is in the AUTO, START or STOP positions and the emergency stop button is not activated. When the emergency stop button is activated, power is removed from the coil of the ECM relay. The contacts of the ECM relay open removing the power to the ECM.The presence of two +Battery connections and two −Battery connections to the ECM reduce harness resistance. All of these connections must be complete in order to ensure proper engine operation.With intermittent faults, you may want to bypass the engine wiring. Bypassing the wiring helps to locate the problem. If the problem is no longer present with the bypass in place, the engine wiring is faulty.
Illustration 1 g01020990
Typical exampleTest Step 1. Check for Connector Damage.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET 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 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 for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are okay.