3500B Industrial Engines Caterpillar

The ECM has the ability to crank the engine when the circuits for the Start/Run/Stop Switches are complete. The crank cycle will continue for the time that is equal to the cycle crank time that has been programmed or the crank cycle will continue until the engine speed reaches the crank terminate speed. If crank terminate speed is not reached before the cycle crank time, the starting motor will deactivate for a time that is equal to the cycle crank time.

This process will repeat for a programmed amount of times (Total Number of Crank Cycles). If the engine does not start the starter mode on the Electronic Service Tool will display "OVERCRANK". The engine control will be in an idle state.

Illustration 1	g00746657

Test Step 1. Check the Electrical Connectors and the Wiring.

1. Turn the Battery switch for the ECM to the OFF position.

2. Turn the breaker at the battery to the OFF position.

3. Thoroughly inspect the ECM connector J1/P1 and J2/P2. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.

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

5. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

6. Check the customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).

7. Check the harness and the wiring for abrasion and pinch points.

Expected Result:

All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring should be free of corrosion, abrasion or pinch points.

Results:

• OK - The wiring and connectors are okay. Proceed to Test Step 2.

• Not OK - Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOP

Test Step 2. Attempt To Start the Engine.

1. Connect an Electronic Service Tool to the Service Tool Connector.

2. Turn the breaker at the battery to the ON position.

3. Turn the Battery switch for the ECM to the ON position.

4. Turn the Start/Run/Stop Switch to the STOP position.

5. Monitor the startup screen on the Electronic Service Tool status screen.

6. Turn the Start/Run/Stop Switch to the RUN position. Monitor the startup screen on the Electronic Service Tool.

7. The crank cycle will continue for the time that is equal to the cycle crank time that has been programmed or the crank cycle will continue until the engine speed reaches the crank terminate speed.

Expected Result:

The startup screen should display "CRANK".

Results:

• OK - The startup screen on the Electronic Service Tool displays "CRANK". Proceed to test step 3.

• Not OK - The startup screen on the Electronic Service Tool does not display "CRANK". Proceed to test step 6.

Test Step 3. Check the Voltage from the Master Start Relay.

1. Turn the Start/Run/Stop Switch to the STOP position.

2. Connect a voltage test lamp between terminal 30 on the master start relay and the engine ground.

3. Turn the Start/Run/Stop Switch to the RUN position.

4. Monitor the voltage test lamp for illumination.

5. Turn the Start/Run/Stop Switch to the STOP position.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates. Proceed to test step 4.

• Not OK - The voltage test lamp did not illuminate. Proceed to test step 7.

Test Step 4. Check the Voltage from the Mag Relays.

1. Connect a voltage test lamp between the wires to the solenoid on the mag relays and the engine ground.

2. Turn the Start/Run/Stop Switch to the RUN position.

3. Monitor the voltage test lamp for illumination.

4. Turn the Start/Run/Stop Switch to the STOP position.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates.

  Repair: Voltage is going to the starter solenoids. Check the solenoids and the starter for proper operation. Repair any damaged components or replace any damaged components.

  STOP

• Not OK - The voltage test lamp did not illuminate. Proceed to test step 5.

Test Step 5. Check the Voltage to the Mag Relay.

1. Connect a voltage test lamp between terminal 3 on the mag relay(s) and engine ground.

2. Turn the Start/Run/Stop Switch to the RUN position.

3. Monitor the voltage test lamp for illumination.

4. Turn the Start/Run/Stop Switch to the STOP position.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates.

  Repair: Check that 24 ± 5 VDC is present at terminal 1 of the mag relay. Check continuity between the wire 229-BK on terminal 4 of the mag relay to the −Battery terminal. If the voltage is present and the wiring is okay replace the mag relay. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage test lamp did not illuminate.

  Repair: The problem is in the wiring and/or connectors between the master start relay and the mag relays. Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

Test Step 6. Check the Start/Run/Stop Switch.

1. Turn the Start/Run/Stop Switch to the STOP position.

2. Connect a voltage test lamp between wire F720-GN on terminal 3 and wire 998-BR on terminal 2 of the Start/Run/Stop Switch.

   Note: The voltage test lamp should illuminate.

3. Turn the Start/Run/Stop Switch to the RUN position.

4. Monitor the voltage test lamp.

Expected Result:

The voltage test lamp should not be illuminated after the Start/Run/Stop Switch is switched to the RUN position.

Results:

• OK - The voltage test lamp is illuminated. The voltage test lamp then turns off. The Start/Run/Stop Switch is operating correctly.

  Repair: The ECM is not responding to the input signal from the Start/Run/Stop Switch. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".

  STOP

• Not OK - The voltage test lamp is illuminated. The voltage test lamp does not turn off. The Start/Run/Stop Switch is not operating correctly.

  Repair: Replace the Start/Run/Stop Switch. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage test lamp does not illuminate with the Start/Run/Stop Switch in the STOP position.

  Repair: Check continuity of the wires and connectors between the Start/Run/Stop Switch and the ECM. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the problem is no longer present.

  STOP

Test Step 7. Check the Voltage to the Master Start Relay.

1. Connect a voltage test lamp between the wire F701-BR on terminal 85 of the master start relay and the − Battery terminal.

2. Turn the Start/Run/Stop Switch to the RUN position.

3. Monitor the voltage test lamp.

4. Turn the Start/Run/Stop Switch to the STOP position.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates.

  Repair: Check that 24 ± 5 VDC is present on the wire 150-OR on terminal 87 of the master start relay. Check the continuity of the wire 229-BK on terminal 86 of the master start relay to the − Battery terminal. If the voltage is present and the wiring is okay replace the master start relay. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage test lamp does not illuminate. Proceed to test step 8.

Test Step 8. Check the Voltage from the ECM.

1. Turn the Battery switch for the ECM to the OFF position.

2. Install a Breakout T at ECM connector J1/P1 and J2/P2.

3. Remove wire 229-BR in socket P1-29 from the Breakout T at J1/P1.

4. Remove wire F701-BR in socket P2-13 from the Breakout T at J2/P2.

5. Connect a voltage test lamp between the wires in P2-13 and P1-29.

6. Turn the Start/Run/Stop Switch to the RUN position.

7. Monitor the voltage test lamp.

8. Turn the Start/Run/Stop Switch to the STOP position.

9. Remove the Breakout T and reconnect the ECM connectors.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates.

  Repair: There is a problem in the wiring and/or connectors between the master start relay and the ECM. Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

• Not OK - The voltage test lamp did not illuminate.

  Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".

  STOP