- Remote shutdown switch
- Electrical power to the Electronic Control Module (ECM)
- ECM personality module
- Air shutoff circuit
- Starting motor solenoid or starting circuit
- Engine speed/timing sensors
- Electrical connections to the electronic unit injector
- Fuel supply
- Combustion problem
- Access the screen on the Caterpillar Electronic Technician (ET) that displays the remote shutdown switch status and verify that there is not an active shutdown.
- Turn the Engine Control Switch (ECS) to the OFF position for at least 15 seconds before attempting to restart the engine.
Note: The power to the ECM must be cycled after an E-Stop and/or a diagnostic shutdown, or the engine will not start.
- Verify that all harness connectors are installed properly.
- Verify that all connections and grounds are tight and free of corrosion. Check the positive battery and negative battery connections to the ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect".
- Verify that the following diagnostic is not active.
- 253-02 Personality Module mismatch
If the code is active, access the "Winflash" and flash the correct version of the software.
Note: If a new ECM has been installed on the engine, the engine will not start until the correct personality module has been flashed into the ECM. The ECM will not communicate with Cat ET until the correct personality module has been flashed into the ECM.
- 253-02 Personality Module mismatch
Refer to Troubleshooting, "Air Shutoff System - Test" for additional information.
Starting Motor Solenoid or Starting Circuit
- Test the operation of the starting motor solenoid.
- Check the engine wiring to the starting motor solenoid.
- Test the operation of the starting motor.
- Inspect the starting motor's pinion and inspect the flywheel ring gear for damage.
Observe the engine speed on Cat ET while the engine is being cranked.
If the engine is cranking and Cat ET displays 0 rpm, a problem exists in the circuits for the engine speed/timing sensors. Refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test".
If an engine speed is present, check the sensor installation. If the sensor is not properly installed, the ECM may read engine speed, but the ECM cannot determine the tooth pattern. The ability for the ECM to read the tooth pattern is necessary to determine the cylinder position. Engine speed is present when engine speed is greater than 50 rpm. Refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test".
Electrical Connections to the Electronic Unit Injectors
- Ensure that the electronic unit injector connector (J91/P91) is fully connected and free of corrosion.
- Check for logged diagnostic codes that are related to the cylinder. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" if diagnostic codes that are related to the cylinder are present.
- Check the fuel level.
- Monitor the exhaust for smoke while the engine is being cranked.
If no smoke is present, there may be a problem with the fuel quality or there may be a problem with the fuel supply.
- Check the fuel pressure. Refer to Testing and Adjusting, "Fuel System Pressure - Test".
- Ensure that the fuel system has been primed. Refer to Testing and Adjusting, "Fuel System - Prime".
- Check for fuel supply lines that are restricted.
- Check the fuel filters.
- If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
Examples of conditions that may cause combustion problems are shown in the following list:
- Cold temperatures
- Injector misfiring
- Low compression
- Mechanical problem
- Valve lash settings
Refer to Testing and Adjusting for more information on a particular problem.