F1844 Force HEX NUT, 1/4 - 20 X 2-3/8

Illustration 1 g06346472Recommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Determine the Code
A. Establish communication between Cat® Electronic Technician (ET) and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Record the logged or active codes.
Code
Result: A E1041 (1) or a 3487-7 code is logged or active.
Proceed to Test Step 2.
Result: A 2490-3, 2490-4, 3488-3 or a 3488-4 code is logged or active. There is a problem with the wiring between the ECM and the combustion air valve.
Proceed to Test Step 7.
Result: A 2489-6 or a 3487-6 code is logged or active. There is a problem with the wiring between the ECM and the combustion air valve.
Proceed to Test Step 10.
Result: A 2489-5, or a 3487-5 code is logged or active. There is a problem with the wiring between the ECM and the combustion air valve.
Proceed to Test Step 11.
2. Inspect the Wiring to the Actuator
A. Inspect the wiring from the ECM to the actuator for the combustion air.
B. Check all connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Check the wires for damage to the insulation.
D. Inspect the wires for the following conditions:
1. Exposed insulation
2. Rubbing of a wire against the engine
3. Rubbing of a wire against a sharp point
E. Perform a pull test on each wire terminal connection. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Damaged Wire or Connector
Result: A damaged wire or damaged connector was not found.
Proceed to Test Step 3.
Result: A damaged wire or damaged connector was found.
Repair: Repair the damaged wire or the damaged connector.
Proceed to Test Step 3.
3. Perform the "ARD Air System Service Test"
A. Perform the "ARD Air System Service Test" in Cat ET.
Test
Result: The "ARD Air System Service Test" passed.
Proceed to Test Step 12
Result: The "ARD Air System Service Test" failed.
Proceed to Test Step 4.
4. Inspect the Piping Between the Compressor and the Combustion Air Valve
A.Inspect the tube between the compressor and the combustion air valve.
B. Check for cracks in the tubing.
C. Check for loose hardware or damaged hardware.
Damaged Tubing
Result: The tube is damaged or cracked.
Repair: Replace the tubing or repair the tubing.
Proceed to Test Step 6.
Result: The tube is not damaged or cracked.
Proceed to Test Step 5.
5. Inspect the Tubing from the Combustion Air Valve to the Combustion Air Absolute Pressure Sensor
A. Inspect the tubing from the combustion air valve to the combustion air absolute pressure sensor.
B. Check for cracks in the tubing.
C. Check for air leaks.
D. Check the clamps on the tube. Make sure that the clamps are tight.
Damaged Tubing
Result: The tube is damaged or cracked.
Repair: Replace the tubing or repair the tubing.
Proceed to Test Step 6.
Result: The tube is not damaged.
Repair: Replace the combustion air valve.
Proceed to Test Step 6.
6. Perform the "ARD Air System Service Test"
A. Perform the "ARD Air System Service Test" in Cat ET.
Test
Result: The "ARD Air System Service Test" passed.
Proceed to Test Step 12.
Result: The "ARD Air System Service Test" failed.
Repair: Replace the combustion air valve. Verify the repair by repeating the "ARD Air System Service Test".
Proceed to Test Step 12.
7. Check the Voltage on the Combustion Air Valve Circuit
A. Turn the keyswitch to OFF.
B. Verify that the harness connector is free of debris, free of corrosion, and securely connected.
C. Disconnect the combustion air valve from the wiring harness.
D. Turn the keyswitch to ON.
E. Verify that there is +5 VDC between the SUPPLY (terminal 1) and RETURN (terminal 2) on the combustion air valve wiring harness connector.
F. Turn the keyswitch OFF.
+5 VDC
Result: There is 5 VDC between the SUPPLY and RETURN on the combustion air valve connector.
Proceed to Test Step 8.
Result: There is not 5 VDC between the SUPPLY and RETURN on the combustion air valve connector. There is a problem with the wiring harness or the ECM.
Repair: Make the necessary repairs.
Proceed to Test Step 12.
8. Create an Open at the Combustion Air Valve Connector
A. Turn the keyswitch OFF.
B. Disconnect the combustion air valve from the wiring harness.
C. Turn the keyswitch ON.
D. Monitor the diagnostic codes on Cat ET. Check for an active -3 code for the combustion air valve.
E. Turn the keyswitch OFF.
Active -3 Code
Result: A -3 code became active after disconnecting the combustion air valve.
Proceed to Test Step 9.
Result: A -3 code did not become active after disconnecting the combustion air valve. There is a problem with the wiring harness or the ECM.
Repair: Make the necessary repairs.
Proceed to Test Step 12.
9. Create a Short at the Sensor Connector
A. Turn the keyswitch OFF.
B. Create a short between the SIGNAL (terminal 3) and RETURN (terminal 2) at the combustion air valve connector.
C. Turn the keyswitch ON.
D. Monitor the codes on Cat ET. Check for an active -4 code for the combustion air valve.
E. Turn the keyswitch OFF.
Active -4 Code
Result: A -4 code became active after creating the short at the combustion air valve connector.
The wiring is OK. Replace the combustion air valve.
Proceed to Test Step 12.
Result: A -4 code did not become active after creating the short at the combustion air valve connector.
There is a problem with the wiring harness or the ECM controller.
Repair: Make the necessary repairs