C7 Engine for the AP-755 Asphalt Paver and the PM-102 Cold Planer Caterpillar

This procedure is used for the 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) remains powered and the Caterpillar Electronic Technician (ET) will continue to communicate with the ECM.

To shut down the engine, toggle the switch to the STOP position. The ECM reads the switch inputs and fuel injection is disabled. If the engine is not running, the ECM will not allow the engine to be started. 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.

Illustration 1	g01274777
Schematic for the engine shutdown switch (PM102)

Illustration 2	g01253357
Schematic for the engine shutdown switch (AP755)

Test Step 1. Inspect the Electrical Connectors and the Wiring

1. Remove the electrical power from the ECM.

Show/hide table



Illustration 3	g01144470
Left side engine view (typical example) (1) J1/P1 ECM connectors

Show/hide table



Illustration 4	g01162689
Left side model view (typical example) (2) Engine shutdown switch

2. Thoroughly inspect all of the connectors and thoroughly inspect all of the connections. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".

Show/hide table



Illustration 5	g01253445
P1 ECM connector (P1-23) Engine shutdown switch (N/O) (P1-40) Engine shutdown switch (N/C)

3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.

4. Check the allen head screw for each of the ECM connectors for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.

5. 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 Status of the Switch Inputs

1. Connect Cat ET to the service tool connector.

2. Toggle the engine shutdown switch to the RUN position.

3. Restore the electrical power to the ECM.

4. Check the status indicators on Cat ET with the power restored to the ECM.

   The status indicator for the user defined shutdown will not be active.

5. Toggle the engine shutdown switch to the STOP position.

6. Check the status indicators on Cat ET with the power restored to the ECM.

   Cat ET will display "Remote Shutdown" with the engine shutdown switch in the STOP position.

7. Return the engine shutdown switch in the RUN position. Remove the electrical power from the ECM.

Expected Result:

The status indicator for the "Remote Shutdown" is displayed on Cat ET per the above procedure.

Results:

• OK - The switch is operating normally.

  Repair: Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.

  STOP

• Not OK - The status of the switch is not displayed per the above specifications.

  Repair: Repeat this step for every shutdown switch in the circuit.

  Proceed to Test Step 3.

Test Step 3. Test the Relay in the De-energized State

1. Disconnect the relay from the circuit.

2. Verify the operation of the relay in the de-energized state.

   1. Measure continuity across the following terminals of the relay:
      • Terminal 1 to terminal 3

      • Terminal 5 to terminal 2

      • Terminal 1 to terminal 4

      Note: Refer to Illustration 1 or refer to Illustration 2 for the terminal locations for the relay.

Expected Result:

The following results were obtained:

• Terminal 1 to terminal 3 indicated a short circuit.

• Terminal 5 to terminal 2 indicated some measured resistance.

• Terminal 1 to terminal 4 indicated an open circuit.

Results:

• OK - Each measurement was correct. Proceed to Test Step 4.

• Not OK - A measurement was incorrect.

  Repair: Replace the relay and retest the circuit.

  STOP

Test Step 4. Test the Relay in the Energized State

1. Verify the operation of the relay in the energized state.

   1. Apply 24 VDC across the coil of the relay.

   2. Measure continuity across the following terminals of the relay:
      • Terminal 1 to terminal 3

      • Terminal 1 to terminal 4

      Note: Refer to Illustration 1 or refer to Illustration 2 for the terminal locations for the relay.

Expected Result:

The following results were obtained:

• Terminal 1 to terminal 3 indicated an open circuit.

• Terminal 1 to terminal 4 indicated a short circuit.

Results:

• OK - Each measurement was correct. Proceed to Test Step 5.

• Not OK - A measurement was incorrect.

  Repair: Replace the relay and retest the circuit.

  STOP

Test Step 5. Short the Wires at the Switch

1. Remove the wires from the terminals on the engine shutdown switch.

2. Install a jumper wire between the wire for the engine shutdown switch (N/C) and the wire for chassis ground.

3. Restore the electrical power to the ECM.

4. Check the status indicators on Cat ET with the power restored to the ECM.

   The status indicator for the user defined shutdown will not be active.

5. Remove the electrical power from the ECM.

6. Remove the jumper wire.

7. Install a jumper wire between the wire for the engine shutdown switch (N/O) and the wire for chassis ground.

8. Restore the power to the ECM and monitor the status indicators on Cat ET.

   Cat ET will display the status indicator for "Remote Shutdown".

9. Remove the electrical power from the ECM.

10. Remove the jumper wire. Reconnect all wires to the original configuration.

Expected Result:

The correct status indicator for the engine shutdown switch is displayed on Cat ET.

Results:

• OK - The correct status indicator for the engine shutdown switch is displayed.

  Repair: The harness and the ECM are OK. There is a problem with the switch. Temporarily connect a new switch. Verify that the new switch solves the problem before you permanently install the new switch.

  STOP

• Not OK - The correct status indicator for the engine shutdown switch was not displayed.

  Repair: Repeat this step for every shutdown switch in the circuit.

  The ECM did not detect the short circuit at the switch. There is a problem in the harness and/or the ECM. Proceed to Test Step 6.

Test Step 6. Short the Switch Inputs at the ECM

1. Remove the electrical power from the ECM.

2. Disconnect theP1 ECM connector. Remove the input wires for the engine shutdown switch from the P1 ECM connector. Reconnect the P1 ECM connector.

3. Use Cat ET to check the status indicator for the user defined shutdown:

   1. Use a jumper wire to connect terminal 23 to chassis ground.

   2. Restore the electrical power to the ECM.

   3. Check the status indicators on Cat ET.

      The status indicator for the engine shutdown switch will not be active.

   4. Remove the electrical power from the ECM.

   5. Remove the jumper wire from terminal 23. Install the jumper wire between terminal 40 and chassis ground.

   6. Restore the electrical power to the ECM.

   7. Monitor the status indicators on Cat ET.

      Cat ET will display the status indicator for "Remote Shutdown".

   8. Remove the electrical power from the ECM.

4. Remove the jumper wire. Reconnect all wires and connectors to the original configuration.

Expected Result:

The correct status indicator for the user defined shutdown is displayed on Cat ET.

Results:

• OK - The correct status indicator is displayed.

  Repair: The ECM is operating properly. The problem is in the harness from the ECM to the engine shutdown switch. Make any necessary repairs. If necessary, replace any parts.

  STOP

• Not OK - The correct status indicator is not displayed.

  Repair: The ECM is not reading the switch inputs properly.Replace the ECM. Refer to electronic Troubleshooting, "Replacing the ECM" before replacing the ECM.

  STOP