LOCKNUT 1K6870 - Caterpillar

Use this procedure in order to troubleshoot a problem with the emergency stop 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
970-2
Engine Auxiliary Engine Shutdown Switch : Erratic, Intermittent, or Incorrect 337-2
Remote Emergency Stop Switch : Erratic, Intermittent, or Incorrect The two inputs from the emergency stop switch are in the opposite state.
The code is logged. Note: The air shutoff is optional. Set the programmable parameter with Cat® Electronic Technician (ET) in order to enable the air shutoff.The 970-31 Engine Auxiliary Engine Shutdown Switch event code will be set when the remote emergency stop switch is activated. This event will prevent engine operation. Electrical power to the ECM must be removed for three seconds in order to clear this event.
Illustration 1 g03885401
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