ORIFICE-SCREEN 2157183 - Caterpillar

Illustration 3 g00970545
Schematic for engine temperature sensors
Illustration 4 g00970546
P1 and P2 ECM connectorsTest Step 1. Inspect Electrical Connectors and Wiring
Thoroughly inspect the J2/P2 ECM connector and the suspect sensor connector. Refer to Troubleshooting, "Electrical Connections - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the sensor connector and the ECM connector that are associated with the active diagnostic code.Refer to Illustration 4.
Verify that the latch tab of the connector is properly latched and that the latch tab of the connector has returned to the Fully Latching position.
Check the ECM Connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasion and pinch points from the sensor to the ECM.Expected Result:All connectors, pins, and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion, or pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - 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. Determine the Condition that is Present
Connect the Caterpillar Electronic Technician (Cat ET) to the data link connector.
Turn the key switch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Check for active diagnostic codes on Cat ET.
Determine if the problem is related to a "voltage high" diagnostic code (open circuit) or a "voltage low" diagnostic code (short circuit).Expected Result:A "voltage high" diagnostic code (open circuit) or a "voltage low" diagnostic code (short circuit) is active.Results:
Voltage High (Open) - A "voltage high" diagnostic code (open circuit) is active at this time. Proceed to Test Step 6.
Voltage Low (Short) - A "voltage low" diagnostic code (short circuit) is active at this time. Proceed to Test Step 3.Test Step 3. Disconnect the Suspect Sensor
Turn the key switch to the OFF position.
Disconnect the sensor with the "voltage low" diagnostic code (short circuit).
Turn the key switch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Check for an active "voltage high" diagnostic code (open circuit) on Cat ET.Expected Result:A "voltage high" diagnostic code (open circuit) for the suspect sensor is now active.Results:
OK - A "voltage high" diagnostic code (open circuit) for the suspect sensor is now active.Repair: Temporarily connect a new sensor.If the new sensor fixes the problem, reconnect the suspect sensor.If the problem returns, permanently replace the sensor.Verify that the repair eliminates the problem.STOP
Not OK - There is a short circuit between the sensor harness connector and the ECM.Repair: Leave the sensor disconnected. Proceed to Test Step 4.Test Step 4. Disconnect the ECM Connector
Turn the key switch to the OFF position.
Disconnect the J2/P2 ECM connector. Thoroughly inspect both halves of the connector for signs of corrosion or moisture.Note: If the Ambient Air Temperature Sensor is being tested, a 140-2266 Cable (Seventy-Pin Breakout) is required in order