0210939 JOHNSON OWNERS MAN., Ev.

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) 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 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 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.
24 3 VDC
Result: The voltage is 24 3 VDC. The output from the emergency stop switch is correct.
Proceed to Test Step 4.
Result: The voltage is not 24 3 VDC at the output of the emergency stop switch.
Repair: There is a problem with the emergency stop switch. There may be a problem in the circuit for the supply voltage to the switch.
Perform the following procedure:
1. Check that the main circuit breaker is not thrown. Reset the breaker, if necessary.
2. Isolate each circuit and check for 24 3 VDC in the following positions:
- RUN position
- OFF position
Note: During the measurements, ensure that the electrical power is restored to the ECM. Ensure that the emergency stop switch is activated.
3. Restore the wiring to the original configuration.
If voltage is 24 3 VDC at the connector for the emergency stop switch, there is a problem with the emergency stop switch. Replace the switch.
If voltage is not 24 3 VDC at one of the test locations, the problem is in the wiring harness. Repair or replace the wiring harness.
If the problem is not resolved, proceed to Test Step 4.
4. Check the Harness Between the Emergency Stop Switch and the Air Shutoff Solenoid
A. Remove the connector from the air shutoff solenoid.
B. Restore the electrical power to the ECM.
C. Connect a voltmeter on the wiring harness side of the connector at the solenoid between the following terminals:
- Control voltage terminal and Return terminal
D. As the emergency stop switch is activated, measure the voltage at the connector in the following positions:
- RUN position
- OFF position
E. Restore the wiring to the original configuration.
24 3 VDC for 2.5 seconds
Result: The voltage is 24 3 VDC for 2.5 seconds.
Repair: The harness between the emergency stop switch and the air shutoff solenoid is OK. There may be a problem with the air shutoff solenoid.
Perform the following procedure:
1. Disconnect the connector from the solenoid. Measure the resistance of the coil at the following terminals:
- Output terminal and Control voltage terminal
The correct resistance of the coil is approximately 33 Ohms at a temperature of 25 °C (77 °F).
If the condition of the solenoid is suspect, replace the solenoid.
2. Verify the mechanical condition of the air shutoff mechanisms. Ensure that the air shutoff mechanisms close freely without binding. Check that adequate oil pressure is reaching the valve assemblies. Perform any necessary repairs.
3. Check that the return circuit has