LINES GP-FUEL INJECTION 1247092 - Caterpillar

The Engine Control Switch (ECS) sends a signal to the keyswitch input of the ECM that tells the ECM the position of the switch. When the ECM senses battery voltage to the keyswitch input of the ECM, the ECM will power up. The keyswitch input receives battery voltage when the ECS is in the AUTO, RUN or STOP mode. When the ECS is in the OFF/RESET position, voltage is not present on P1-70 and the ECM will power down. Cycling power to the keyswitch input of the ECM will reset the ECM and all active diagnostic codes. In addition to turning the ECS to the OFF/RESET position, the operator must manually open the air shutoff valves before starting the engine.The presence of three +Battery connections and three −Battery connections to the ECM reduce harness resistance. All of these connections must be complete in order to ensure proper engine operation.The electrical power for the generator set control comes through a 20 amp circuit breaker to the relay module and to the high voltage ground.
Illustration 1 g01443822
Typical example
Illustration 2 g01444508
Location of the ECM connectors (1) J2/P2 ECM connectors (2) J1/P1 ECM connectors
Illustration 3 g01443785
P1 ECM connector (P1-21) Start/Run/Stop1 (P1-22) Start/Run/Stop2 (P1-23) E-Stop signal 1 (P1-28) E-Stop signal 2 (P1-52) +Battery (P1-53) +Battery (P1-55) +Battery (P1-63) -Battery (P1-65) -Battery (P1-67) -Battery (P1-70) Keyswitch
Illustration 4 g01443788
Generator connector (4) Auxiliary power (5) Auxiliary power (16) Start/Run/Stop1 (16) Start/Run/Stop2 (17) E-Stop signal 2 (18) Keyswitch (19) E-Stop signal 1 (39) -Battery (40) -BatteryTest Step 1. Inspect the Electrical Connectors and Wiring
Turn the ECS to the OFF/RESET position. Turn the main disconnect switch to the OFF position.
Thoroughly inspect the ECM connectors. Inspect all of the other connectors for the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" 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. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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 - 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
Measure no-load voltage at the battery posts. Refer to Systems Operation/Testing and Adjusting 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 no-load voltage at the batteries is at least 23.5 VDC,