PUMP GP-UNIT INJECTOR HYD 1440837 - Caterpillar

Illustration 1 g03731618
Schematic diagram for the ammonia sensor
Not all connectors are shown. Refer to the Electrical Schematic for the application.
Illustration 2 g03729557
View of the pin locations on the P1 connector for the ammonia sensor.
(23) J1939 CAN 2 +
(45) J1939 CAN 2 -
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Check the fuses.
B. Thoroughly inspect the connectors for the ammonia sensor. Refer to Troubleshooting, "Electrical Connector - Inspect" for details.
C. Thoroughly inspect the P1/J1 ECM connector . Refer to Troubleshooting, "Electrical Connector - Inspect" for details.
D. Perform a 30 N (6.7 lb) pull test on each of the wires that are associated with the ammonia sensor.
Damaged wire or connector
Result: A damaged wire or damaged connector was found. A fuse is blown.
Repair: Repair the damaged wire or the damaged connector. Replace any blown fuses.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points. The fuses are OK.
Proceed to Test Step 2.
2. Check for Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position.
D. Monitor the electronic service tool for active diagnostic codes and/or logged diagnostic codes.
Diagnostic codes
Result: A diagnostic code other than those listed in Table 1 is active or recently logged.
Repair: Troubleshoot the other diagnostic codes before returning to this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: One of the diagnostic listed in Table 1 is active or recently logged.
Proceed to Test Step 3.
Result: None of the diagnostic codes listed in Table 1 are active or recently logged.
Repair: The fault may be intermittent. Refer to Troubleshooting, "Electrical Connector - Inspect" in order to identify intermittent faults.
3. Inspect the Exhaust System for Defects
A. Thoroughly inspect the exhaust system for leaks and/or restrictions. Refer to Systems Operation, Testing and Adjusting, "Air Inlet and Exhaust System - Inspect".
Exhaust leaks
Result: There is a leak in the exhaust system.
Repair: Make any necessary repairs.
Run the engine. Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.
Result: The exhaust system is restricted with white deposits.
Repair: Refer to Troubleshooting, "Exhaust System Contains DEF Deposits"
Result: The exhaust system is OK.
Proceed to Test Step 4.
4. Inspect the Ammonia Sensor
A. Inspect the ammonia sensor for damage.
B. Check that the ammonia sensor is mounted in the correct position.
C. Ensure that the ammonia sensor is mounted securely
Ammonia sensor
Result: Fault found with the ammonia sensor.
Repair: Make any necessary repairs. If necessary, replace a damaged ammonia sensor. Refer to Disassembly and Assembly for the correct procedure.
Run the engine. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The ammonia sensor is mounted securely and not damaged.
Proceed to Test Step 5.
5. Check the Power Supply at the Ammonia Sensor
A. Turn the keyswitch to the OFF position.
B.