5031787 JOHNSON *COVER, TRIM SWITCH

Table 1
Diagnostic Trouble Codes
CDL Code Code Description Comments
E678 (1) Ground Level Shutdown The inputs from the ground level shutdown switch to the Electronic Control Module (ECM) have changed states.
The engine will shut down. The code is logged.
E678 (2) Ground Level Shutdown The inputs from the ground level shutdown switch to the Electronic Control Module (ECM) have changed states.
The engine will shut down. The code is logged.
E678 (3) Ground Level Shutdown The inputs from the ground level shutdown switch to the ECM have changed states.
The engine will shut down. The code is logged.
267-3 Remote Shutdown Input : Voltage Above Normal If both contacts from the ground level shutdown switch change to the same state and the engine is running, the engine will continue to run. The code is logged.
267-4 Remote Shutdown Input : Voltage Below Normal If both contacts from the ground level shutdown switch change to the same state and the engine is running, the engine will continue to run. The code is logged. The shutdown switch will shut down the engine. The engine ECM remains active. Caterpillar Electronic Technician (ET) can be used to communicate with the ECM. The shutdown switch must be returned to the RUN position before the ECM will allow the engine to start.The ECM reads the position of the shutdown switch. If the engine is running, the ECM disables the fuel injection. The status screen will display"Injection Disabled" and "Remote Shutdown".
Illustration 1 g03018516
Schematic
Illustration 2 g02048916
P1 ECM connector
(P1-40) shutdown (NO)
(P1-41) shutdown (NC)
(P1-5) Return
Table 2
Troubleshooting Test Steps Values Results
1. Determine the Diagnostic Code
A. Establish communication between Cat ET and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active.
C. Look for these codes:
E678 (1)
E678 (2)
E678 (3)
267-3
267-4
Diagnostic Trouble codes
Result: A E678 diagnostic code is active.
Proceed to Test Step 2.
Result: A 267-3 diagnostic code is active.
Proceed to Test Step 3.
Result: A 267-4 diagnostic code is active.
Proceed to Test Step 4.
2. Check the Status of the Shutdown Switch on Cat ET
A. Activate the shutdown.
B. Use Cat ET to verify that the engine rpm is 0. Return the shutdown switch to the RUN position.
C. Use Cat ET to observe the status of the shutdown switch.
Switch status
Result: The status of the shutdown switch changed states after returning the shutdown switch to the RUN position.
The shutdown switch is operating correctly.
Result: The status of the shutdown switch does not change states after returning the shutdown switch to the RUN position.
Proceed to Test Step 3.
3. Create a Short at the Connector for the Shutdown Switch
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the shutdown switch.
C. Create a short circuit at the connector for the shutdown switch between terminal 1 and terminal 2.
D. Turn the keyswitch to the ON position.
E. Use Cat ET to observe the status of the shutdown switch.
F. Remove the wire short.
Short circuit
Result: The status of the shutdown switch changed states after creating the short circuit.
Install a new shutdown switch.
Verify that the problem is resolved.
Result:The status of the shutdown switch did not change states after creating the short circuit.
Repair the wiring or replace the harness.
Use Cat ET to verify that the problem is resolved.
4. Create an Open at the Connector for the Shutdown Switch
A. Turn the keyswitch to the OFF position.
B.Disconnect the connector for the shutdown switch.
C. Turn the keyswitch to the ON position.
D. Use Cat ET to observe the status of the shutdown switch.
Open circuit detected
Result: The status of the shutdown switch changed states after creating the open circuit.
Install a new shutdown switch.
Use Cat ET to verify that the problem is resolved.
Result: The status of the shutdown switch did not change states after creating the open circuit.
Repair the harness or replace the harness.
Use Cat ET to verify that the problem is resolved.
Complete the procedure in the order in which the steps are listed.If the procedure corrected the issue, return the engine to service.If the procedure did not correct the issue, Contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).