This procedure is used for the following diagnostic code:
- 267-02 Incorrect Engine Shutdown Switch inputs
The engine shutdown switch allows the operator to shut down the engine from outside of the cab. The Electronic Control Module (ECM) will remain active and the Caterpillar Electronic Technician (ET) will continue to communicate with the ECM. The engine shutdown switch must be returned to the RUN position and the keyswitch must be cycled to the OFF position before the ECM will allow the engine to start.
To shut down the engine, toggle the switch to the STOP position. The ECM reads the switch position. If the engine is running, the ECM disables fuel injection. If the engine is not running, the ECM will not allow the engine to start.
The voltage at P1-46 (engine shutdown switch (NO)) at the ECM should be 11.5 ± 0.5 VDC with the switch in the RUN position. The voltage at P1-47 (engine shutdown switch (NC)) at the ECM should be less than 0.5 VDC with the switch in the RUN position.
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| Illustration 1 | g01260194 |
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Schematic for the engine shutdown switch | |
Test Step 1. Inspect Electrical Connectors and Wiring
- Remove the electrical power from the ECM.
- Thoroughly inspect the J1/P1 ECM connector. Thoroughly inspect the connector for the engine shutdown switch. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Show/hide table
Illustration 2 g01235972 P1 ECM connector
(P1-5) Digital return
(P1-46) Engine shutdown switch (NO)
(P1-47) Engine shutdown switch (NC) - 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 the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
- Check the harness and the wiring for abrasion and for pinch points.
Expected Result:
All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.
Results:
- OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
- Not OK - The connectors and/or wiring are not OK.
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 completely coupled.
Verify that the repair eliminates the problem.
STOP
Test Step 2. Check the Switch Status on Cat ET
- Connect Cat ET to the service tool connector.
- Restore the electrical power to the ECM.
- Observe the status for "Shutdown Switch" on Cat ET while you operate the engine shutdown switch.
- Remove the electrical power from the ECM.
Expected Result:
The status is "On" with the switch in the STOP position. The status is "Off" with the switch in the RUN position.
Results:
- OK - The switch is operating normally.
Repair: Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" if an intermittent electrical problem is suspected.
STOP
- Not OK - The status of the shutdown switch is incorrect. Proceed to Test Step 3.
Test Step 3. Short the Wires at the Switch
- Disconnect the connector for the engine shutdown switch.
- Install a jumper wire between B (Engine shutdown switch (NC) and C (Digital sensor return).
- Restore the electrical power to the ECM and observe the status for "Shutdown Switch" on Cat ET.
The status should be "Off".
- Remove the electrical power from the ECM.
- Remove the jumper wire.
- Install the jumper wire between A (Engine shutdown switch (NO) and C (Digital sensor return).
- Restore the electrical power to the ECM and observe the status for "Shutdown Switch" on Cat ET.
The status should be "On".
- Remove the electrical power from the ECM.
- Remove the jumper wire.
Expected Result:
The status is "Off" with the jumper wire between B (Engine shutdown switch (NC) and C (Digital sensor return). The status changes to "On" when you move the jumper wire to A (Engine shutdown switch (NO) and C (Digital sensor return).
Results:
- OK - The wiring from the connector to the ECM is OK. There is a problem with the switch.
Repair: Temporarily connect a new switch. Verify that the new switch solves the problem before you permanently install the new switch.
STOP
- Not OK - The ECM did not detect the shorts. There is a problem in the harness and/or the ECM. Proceed to Test Step 4.
Test Step 4. Short the Switch Inputs at the ECM
- Remove the electrical power from the ECM.
- Install a 208-0059 Adapter Cable As (70-PIN BREAKOUT) at the J1/P1 ECM connector.
- Install a jumper wire between P1-47 (Engine shutdown switch (NC) and P1-5 (Digital sensor return) at the breakout.
- Restore the electrical power to the ECM and observe the status for "Shutdown Switch" on Cat ET.
The status should be "Off".
- Remove the electrical power from the ECM.
- Remove the jumper wire from the breakout.
- Install the jumper wire between P1-46 (Engine shutdown switch (NO) and P1-5 (Digital sensor return) at the breakout.
- Restore the electrical power to the ECM and observe the status for "Shutdown Switch" on Cat ET.
The status should be "On".
- Remove the electrical power from the ECM.
Expected Result:
The status is "Off" with the jumper wire between P1-47 (Engine shutdown switch (NC) and P1-5 (Digital sensor return). The status changes to "On" when you move the jumper wire to P1-46 (Engine shutdown switch (NO) and P1-5 (Digital sensor return).
Results:
- OK - The ECM properly reads the inputs for the shutdown switch at the ECM connector P1 but not at the connector for the switch.
Repair: The wiring harness is faulty. Repair the wiring harness. Verify that the repair eliminates the problem.
STOP
- Not OK - The ECM is not reading the inputs for the shutdown switch properly.
Repair: Verify your results.
Replace the ECM. Refer to electronic troubleshooting Troubleshooting, "Replacing the ECM" before replacing the ECM.
STOP