FRAME AS 5L7439 - Caterpillar

Probable Causes
Fuel Supply
Engine Shutdown Switches (if applicable)
Starting Aids (if applicable)
Air Inlet and Exhaust System
Theft Deterrent System (if applicable)
Sensors
Engine Speed/Timing
Fuel SystemRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
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.
2. 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.
Switches are in the OFF position
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.
3. Starting Aids (if applicable)
If cold ambient conditions exist, check the operation of the starting aids.
Verify that the starting aid is operating correctly.
Starting aids are operational
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 Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System" for additional information on the air inlet and exhaust systems.
Repair: Replace plugged air filters. Refer to the Operation and Maintenance Manual for the correct procedure.
5. Theft Deterrent System (if applicable)
A. Verify that the theft deterrent system is not active.
Theft system is inactive.
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. Sensors
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 on Cat ET is reasonable for the conditions that are present.
Sensor output
Result: The sensor is operating properly.
Proceed to Test Step 7.
Result: The sensor is