RING-LOCKING 1655854 - Caterpillar

System Operation Description:The analog sensor supply provides power to all analog sensors. The engine's Electronic Control Module (ECM) supplies 5.0 0.2 VDC from the ECM connector J1/P1 to each analog sensor connector. The sensor return line connects to the ECM connector J1/P1. The analog sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.Note: The analog sensors are not protected from overvoltage. A short from the analog supply line to the +Battery supply may damage the sensors. If CID-FMI 262-03 is logged, it is possible that all of the analog sensors have been damaged. Repair the analog sensor supply and check for any "ACTIVE" sensor diagnostic codes in order to determine if a sensor has failed.The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. Refer to the calibration procedure Troubleshooting, "Anolog Sensor - Calibrate".The following analog sensors are found on the engine: aftercooler temperature sensor, coolant temperature sensor, filtered fuel pressure sensor, unfiltered fuel pressure sensor, filtered engine oil pressure sensor, unfiltered engine oil pressure sensor, left turbocharger compressor inlet pressure sensor, right turbocharger compressor inlet pressure sensor, turbocharger compressor outlet pressure sensor, atmospheric pressure sensor and crankcase pressure sensor.
Illustration 1 g01001876
Typical example
Test Step 1. Check for Connector Damage
Turn the circuit breaker for the battery to the OFF position.
Turn the Engine Control Switch (ECS) to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to 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 allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the correct torque values.
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, and of pinch points.Results:
OK - The connectors and wiring are OK. 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.STOPTest Step 2. Check the Harness for Shorts
Disconnect the primary ECM connector J1/P1. Disconnect all of the analog sensors.
Measure the resistance between the analog supply P1-02 and the analog return P1-03.
Measure the resistance between P1-18 and P1-35.
Measure the resistance between P1-02 and engine ground.
Measure the resistance between P1-03 and engine ground.
Measure the resistance between P1-18 and engine ground.
Measure the resistance between P1-35 and engine ground. Expected Result:The resistance is more than 20,000 Ohms for each measurement.Results:
OK - The resistance is more than 20,000 Ohms for each measurement. Proceed to Test Step 3.
Not OK - The resistance is less than 20,000 Ohms for