C9.3 Engines for Caterpillar Built Machines Engine Cranks but Does Not Start Caterpillar

Engine Cranks but Does Not Start

C9.3 Engines for Caterpillar Built Machines [KENR5393]

C9.3 Engines for Caterpillar Built Machines Coolant Temperature Is Low

C9.3 Engines for Caterpillar Built Machines Engine Does Not Crank

ELECTRICAL AND STARTING SYSTEM

MOTOR GP

C9.3 Engines for Caterpillar Built Machines Engine Cranks but Does Not Start

C9.3 Engines for Caterpillar Built Machines Engine Does Not Crank

Download the Product Status Report from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes. Troubleshoot any active codes before continuing with this procedure.

Probable Causes

Note: If the engine will not start and Cat ET will not communicate with the ECM, the problem is most likely with the electrical power supply to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test".

Fuel Supply
Engine Shutdown Switches (if applicable)
Starting Aids (if applicable)
Restrictions in the Air Inlet and Exhaust System
Theft Deterrent System (if applicable)
Coolant Temperature Sensor
Engine Speed/Timing
Low-Pressure Fuel System
High-Pressure Fuel System

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in order.

Show/hide table

Table 1
Troubleshooting Test Steps	Values	Results
1. Inspection of the Fuel Supply A. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only. B. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.	Fuel Level	Result : The fuel level is OK. Proceed to Test Step 2. Result : The fuel level is not OK. Repair : Fill the tank. STOP
2. Check the Engine Shutdown Switches (if applicable) A. The engine shutdown switches must be in the OFF position. B. Use Cat ET to verify the status of the engine shutdown switches. When a shutdown occurs, the keyswitch must be turned to the OFF position for at least 15 seconds before restarting the engine.	Engine Shutoff Switches	Result : The switches are in the OFF position. Proceed to Test Step 3. Result : The switches are not in the OFF position. Repair : Turn the switches to the OFF position. STOP
3. Check the Engine Starting Aids (if applicable) A. If cold ambient conditions exist, check the operation of the starting aids. Verify that the starting aid is operating correctly.	Starting Aids	Result : The starting aid is operating correctly. Proceed to Test Step 4. Result: The starting aid is not operating correctly. Repair : Refer to the appropriate circuit test in order to troubleshoot the starting aid.
4. Restrictions in the Air Inlet and Exhaust System A. Check for an air filter restriction indicator. B. Check the air inlet and exhaust system for restrictions and/or leaks.	Air and Exhaust System Restrictions	Result : There are no system restrictions. Proceed to Test Step 5. Result : There are system restrictions. Refer to Testing and Adjusting, "Air Inlet and Exhaust System - Inspect" for more information on air system restrictions. Repair : Replace plugged air filters. Refer to the Operation and Maintenance Manual for the correct procedure.
5. Check for Activation of the Theft Deterrent System (if applicable) A. Verify that the theft deterrent system is not active.	Theft Deterrent System	Result : The theft deterrent system is not active. Proceed to Test Step 6. Result : The theft deterrent system is active. Repair : Turn the theft deterrent system OFF.
6. Check the Coolant Temperature Sensor for Proper Operation A. The coolant temperature sensor must provide a correct signal in order for cold mode operation to operate correctly. Refer to "Cold Mode Operation" within the Systems Operation, "General Information". B. Verify that the coolant temperature reading in Cat ET is reasonable for the conditions that are present.	Coolant Temperature Sensor	Result : The sensor is operating properly. Proceed to Test Step 7. Result : The sensor is not operating properly. Repair : Refer to Troubleshooting, "Sensor Signal (Analog, Passive) - Test" for troubleshooting information.
7. Check the Engine/Speed Signal for Proper Operation A. Crank the engine and observe the engine speed on the Cat ET status screen. Refer to Troubleshooting, "Speed/Timing - Test" for additional information. Upon initial cranking, the status for engine speed may indicate that the engine speed signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal.	Timing Signal	Result : The timing sensor is operating properly. Proceed to Test Step 8. Result : The timing sensor is not operating properly. Repair : Refer to Troubleshooting, "Speed/Timing - Test" for troubleshooting information.
8. Inspect the Low-Pressure Fuel System A. Inspect the fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for additional information. B. Cold weather adversely affects the characteristics of the fuel. Refer to the engines Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation. C. Check fuel quality. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for the proper procedure. Check the fuel tank for debris or foreign objects which may block the fuel supply. D. Check the filtered fuel pressure while the engine is being cranked. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for the test procedure and for the correct pressure values. If the fuel pressure is low, replace the fuel filters. Clean the primary filter/water separator of debris. Refer to the Operation and Maintenance Manual for details. E. Check for the proper operation of the fuel transfer pump. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for test information.	Low-Pressure Fuel System	Result : The low-pressure fuel system is operating properly. Proceed to Test Step 9. Result : The low-pressure fuel system is not operating properly. Repair : Make the necessary repairs. Return the engine to service.
9. Inspect the High-Pressure Fuel System A. Perform the Testing and Adjusting, "Injector Bypass Fuel Flow - Test" to test the high-pressure fuel system.	High-pressure Fuel System	Result : The high-pressure fuel system is not operating properly. Repair : Make the necessary repairs. Return the engine to service.