ALARM GP 9G9812 - Caterpillar

Illustration 1 g00599048
Typical exampleTest Step 1. Check for Connector Damage.
Turn the 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 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. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. Stop.Test Step 2. Check for a Short Circuit in the Harness.
Disconnect ECM connector J1/P1. Disconnect all of the analog sensors.
Measure the resistance between the analog supply P1-36 and the analog return P1-30.
Measure the resistance between the analog supply P1-36 and the engine ground.
Measure the resistance between the analog return P1-30 and the engine ground.Expected Result:The resistance is more than 20,000 Ohms for each measurement.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to Test Step 3.
Not OK - The resistance is less than 20,000 Ohms.Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. Stop.Test Step 3. Check the Analog Sensor Supply Voltage at the ECM.
Remove wire 997-OR from P1-36. Install a wire jumper into P1-36.
Remove wire 993-BR from P1-30. Install a wire jumper into P1-30.Note: If you remove the sensor common from the ECM, an open circuit diagnostic code will be generated for all sensors that use the sensor common. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Turn the circuit breaker for the battery to the ON position.
Turn the ECS to the STOP position on