COUPLING 5078035 - Caterpillar

Illustration 1 g03866250
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Verify that the air shutoff mechanisms are set to the OPEN position.
C. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
D. Perform a 45 N (10 lb) pull test on the connector wires.
E. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 2.
2. Test the Operation of the Control Solenoid for the Air Shutoff Relay and Check for Logged Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Restore the electrical power to the ECM.
C. Test the air shutoff system with the emergency stop switch:
a. Start the engine.
b. Place the emergency stop switch in the STOP position.
c. Check the position of the air shutoff mechanisms. Activation of the emergency stop will activate the air shutoff system and the air shutoff mechanisms will close.
d. Check that the solenoid has de-energized after the air shutoff mechanisms are closed.
e. Turn the main disconnect switch to the OFF position.
D. Check the status of the "Air Intake Shutoff Position" parameter.
a. Connect Cat ET.
b. Use Cat ET to check the status of the "Air Intake Shutoff Position" parameter while the air shutoff mechanisms are shut.
c. Reset the air shutoff mechanisms.
d. Use Cat ET to check the status of the "Air Intake Shutoff Position" while the air shutoff mechanisms are open.
E. Use Cat ET to check for the following logged code:
- 970-2
F. Reset the air shutoff mechanisms for the air shutoff to the open position.
a. Place the emergency stop switch in the RUN position.
b. Turn the main disconnect switch to the OFF position.
c. Restore the wiring to the original configuration.
Codes
Result: The valve mechanism did not close when the emergency stop switch is activated. There is a logged 970-2 code.
Proceed to Test Step 3.
Result: The valve mechanisms are operating correctly. There are no codes logged during the test.
Repair: The air shutoff system appears to be operating correctly. There may be an intermittent problem in the wiring harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for additional information.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Voltage at the Emergency Stop Switch (Customer)
A. Remove the wire from the output terminal at the connector for the emergency stop switch.
B. Restore the electrical power to the ECM.
C. Measure the voltage between the following:
- Emergency shutdown switch output terminal and −Battery
D. As the emergency stop switch is activated, measure the voltage at the output of the switch in the following positions:
- RUN position
- OFF position
E. Restore the wiring to the original configuration.
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