NUT 6B4540 - Caterpillar

Use this procedure to troubleshoot a problem with the air shutoff system. Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
2813-5
Engine Air Shutoff Command Status : Current Below Normal 3239-5
Air Shutoff Relay : Current Below Normal The code is logged.
2813-6
Engine Air Shutoff Command Status : Current Above Normal 3239-6
Air Shutoff Relay : Current Above Normal The code is logged.
3667-2
Engine Air Shutoff Status : Erratic, Intermittent, or Incorrect E2088 (1)
Air Intake Shutoff Detection Circuit Detected but Not Installed The inlet air shutoff valve switch has been used, but the inlet air shutoff valve feature is set as "Disabled" in the configuration parameters.
3667-31
Engine Air Shutoff Status E2087 (3)
Air Intake Shutoff Closed The engine air shutoff valve has been activated. The engine was shutdown and injection is disabled. Perform a key cycle and reset the air inlet shutoff system. Note: The "Air Shutoff" parameter must be set to "Enabled" in order for the Electronic Control Module (ECM) to energize the air shutoff solenoid.
Illustration 1 g03732167
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: An E2088 (1) or 3667-2code is active or logged.
Proceed to Test Step 12.
Result: A 3239-6 or 2813-6 code is active or logged.
Proceed to Test Step 11.
Result: A 3239-5 or 2813-5 code is active or logged.
Proceed to Test Step 10.
Result: A 3667-31 or E2087 (3) code is active or logged, or the air inlet shutoff valve is not working properly.
Proceed to Test Step 2.
2. Perform the "Air Inlet Shutoff Override"
A. Connect Cat ET.
B. Place the transmission in neutral.
If the engine will not start, check the air inlet valve to ensure that the valve is not stuck closed.
C. Start the engine. Increase the engine speed to 1500 rpm 100 rpm.
D. Use Cat ET to perform the following test:
- "Air Inlet Shutoff Override"
E. Start the test.
F. Wait for the engine to stop.
G. Stop the test.
Air Shutoff
Result: The engine did not shutdown.
Proceed to Test Step 5.
Result: The engine is shutdown when the "Air Inlet Shutoff Override" is activated. The air inlet shutoff is working correctly.
Repair: Reset the air inlet shutoff system.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Air Inlet Shutoff Switch
A. Connect Cat ET.
B. Use Cat ET to monitor the status for the air inlet shutoff switch while the switch is depressed.
Switch
Result: The status of the switch changed in Cat ET.
The inlet air shutoff switch is operating properly. Return to service.
Result: The status of the switch did not change in Cat ET.
Proceed to Test Step 4.
4. Check the Circuit to the Air Inlet Shutoff Switch
A. Turn the main disconnect to the OFF position.
B. Remove the air inlet shutoff switch.
C. Connect Cat ET.
D. Short the terminals of the air inlet shutoff switch together. This will simulate the switch being closed.
E. Use Cat ET to monitor the status for the air inlet shutoff switch