889833025 Mercury SCREW, (M8 x 25)

Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
970-2 Engine Auxiliary Engine Shutdown Switch : Erratic, Intermittent, or Incorrect The two inputs from the emergency stop switch are in the opposite state. The code is logged. The Electronic Control Module (ECM) receives two signals from the emergency stop switch. The signals allow the ECM to determine the status of the emergency stop switch. The ECM will shut down the engine when both of the signals are open. With both signals connected to the return the emergency stop switch is not active and the engine will run. Refer to Illustration 3.If two different signals are detected during the powerup, the ECM will determine that one of the signals is incorrect. A diagnostic code will be logged and a diagnostic code will remain active. The engine will continue to run when the ECM detects two different signals. If both of the signals are open, the engine will stop.The customer can install multiple emergency stop switches. If the emergency stop switch is activated, the ECM will stop firing the injectors. The engine will stop.The electrical power to the input for the keyswitch must be turned OFF for 15 seconds. The engine ECM will then be reset after an emergency stop condition.
Illustration 1 g02699840
Typical schematic
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the main disconnect switch to the OFF position.
Thoroughly inspect connector (1). Also, thoroughly inspect the engine interface connector. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 2 g02721290
Location of the J1/P1 and the J2/P2 ECM connectors (typical engine view)
(1) J1/P1 ECM connector
(2) J2/P2 ECM connector
Illustration 3 g02723882
P1 ECM connector
(P1-5) Digital return
(P1-23) Emergency shutdown 1
(P1-56) Emergency shutdown 2
Illustration 4 g02760958
Engine interface connector
(Terminal 5) Digital return
(Terminal 22) Emergency shutdown 1
(Terminal 23) Emergency shutdown 2
(Terminal 54) + Battery relay control
(Terminal 55) + Battery relay control
Illustration 5 g02760977
Power interface connector
(Terminal 4) + Battery ECM
(Terminal 5) + Battery ECM
(Terminal 49) + Battery
(Terminal 52) + Battery
(Terminal 61) + Battery relay control
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points. Expected Result:All connectors, pins, and sockets are coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status while the Emergency Stop Switch is Active
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
Start Cat ET.
Use Cat ET to observe the status of the emergency stop switch.
Activate the emergency stop switch. If multiple emergency stop switches have been installed, ensure that any other emergency stop switch has not been activated. Expected Result:The status for the emergency stop switch reads "ON".Results:
OK - The status for the emergency stop switch reads "ON". Proceed to Test Step 3.
Not OK - The status for the emergency stop switch does not read "ON". Proceed to Test Step 4.Test Step 3. Check the Status while the Emergency Stop Switch is Not Active
Deactivate the emergency stop switch.
Use Cat ET to observe the status of the emergency stop switch. Expected Result:The status for the emergency stop switch reads "OFF".Results:
OK - The status for the emergency stop switch reads "OFF".Repair: The emergency stop switch is functioning correctly. There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The status for the emergency stop switch does not display "OFF". Proceed to Test Step 4.Test Step 4. Install a Jumper Wire at the Emergency Stop Inputs to the ECM
Turn the main disconnect switch to the OFF position.
Disconnect ECM connector J1/P1.
Remove the wire from the ECM connector P1-23. Install a wire jumper into the socket for P1-23.
Remove the wire from the ECM connector P1-56. Install a wire jumper into the socket for P1-56.
Connect ECM connector J1/P1.
Restore electrical power to the ECM.
Use Cat ET to observe the status of the emergency stop switch.
Fabricate a jumper wire. Connect the wire jumpers in socket P1-23 and P1-56 to the digital return at socket P1-5.
Use Cat ET to observe the status of the emergency stop switch.
Restore electrical power to the ECM. Restore the wiring and the connectors to the original configuration. Expected Result:The status of the emergency stop switch reads "ON" when the jumper is not installed. The status of the emergency stop switch reads "OFF" when the jumper is installed.Results:
OK - The status for the emergency stop switch is displaying the proper states. The problem is not with the ECM. Proceed to Test Step 5.
Not OK - The status for the emergency stop switch is not displaying the proper states.Repair: Perform the following procedure:
Temporarily connect a test ECM. Refer to Troubleshooting, "ECM - Replace".
Recheck the circuit in order to ensure that the original problem has been resolved. If the problem is resolved with the test ECM, install the suspect ECM. If the problem returns with the suspect ECM, replace the ECM. Verify that the problem is resolved.If the problem is not resolved with the test ECM, install the original ECM. There is a problem in the wiring.STOPTest Step 5. Check the Switches and the Wiring when the Emergency Stop is Activated