SWITCH- 4473101 - Caterpillar

Illustration 8 g01741073
Terminal locations at the harness connectors that are for the NOX sensor
(Terminal 1) Digital supply(24 V)
(Terminal 2) Return
(Terminal 3) CAN Data Link −
(Terminal 4) CAN Data Link +
(Terminal 5) Shield
Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the NOX sensor.
Check the torque of the allen head screws for each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the battery to the junction box. Check that the fuses for the circuit are not blown. Expected Result:All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The connectors and the wiring appear to be OK. Proceed to Test Step 2.
Not OK - The components are not in good repair and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.STOPTest Step 2. Check for Active Diagnostic Codes and Event Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the engine. Set the engine control switch to the STOP position. Start the engine. Allow the engine to reach the normal operating temperature.
Check for the following active codes:
3002-2 Engine Exhaust NOx Level Sensor erratic, intermittent, or incorrect
3002-9 Engine Exhaust NOx Level Sensor abnormal update rate
3002-12 Engine Exhaust NOx Level Sensor failure
E717 Engine Exhaust NOx Level Sensor Operating Temperature Not ReachedNote: Monitor the active diagnostic codes and the event codes on Cat ET. Wait at least 30 seconds in order for diagnostic codes to become active.
Shut down the engine. Set the engine control switch to the OFF/RESET position. Remove the electrical power from the engine. Expected Result:There is not an active code for the NOX sensor at this time.Results:
OK - There is not an active code for the sensor at this time.Repair: There does not appear to be a problem in the circuits of the NOX sensor at this time. If one of these codes is logged there may be an intermittent problem with one of the circuits. If there is a logged code, or an intermittent electrical problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for information that is related to troubleshooting intermittent electrical problems.STOP
Active 3002-2 - A 3002-2 diagnostic code is active at this time.Repair: The NOX sensor reported that the data from the sensor is incorrect. Perform the following procedure:
Check the stability of the engine:
Start the engine. Allow the engine to warm to operating temperature.
Use Cat ET to monitor the engine rpm for a two minute period. Check that the engine rpm remains stable within ten rpm from the engine speed setpoint that is given in Cat ET.An unstable engine rpm can cause the NOX concentrations in the