Engine Does Not Crank
Use this procedure to troubleshoot an engine that will not crank.
Complete the procedure in the order in which the steps are listed.
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| Troubleshooting Test Steps | Values | Results |
|---|---|---|
1. Inspection of the Batteries and Battery Cables A. Inspect the main power switch, battery posts, and battery cables for loose connections and for corrosion. If the battery cables are corroded, remove the battery cables and clean the battery cables. Tighten any loose connections. B. Inspect the batteries. C. Charge the batteries. Refer to Special Instruction, SEHS7633, "Battery Test Procedure". Test the batteries. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6 v, 8 v, and 12 v Lead Acid Batteries". |
Batteries |
Result The batteries and cables are OK. Proceed to Test Step 2. Result The batteries and cables are not OK. Repair: Make the necessary repairs. |
2. Machine Security System (MSS) A. Check that the correct ignition key is being used. B. Check that the CAN Data Link is operating correctly. Refer to Troubleshooting, "CAN Data Link - Test". |
MSS |
Result: An incorrect ignition key is being used. Repair: Obtain the correct key and confirm that the engine starts. Result: A fault is identified on the CAN data link. Repair: Make the necessary repairs. Result: The correct ignition key is being used and the CAN data link is OK. Proceed to Test Step 3. |
3. Switches and/or Circuit Breakers (if applicable) A. Check any switches and/or circuit breakers that may prevent engine cranking. For additional information, refer to the machine electrical schematic. |
Switches and/or circuit breakers |
Result: The switches and/or circuit breakers are OK. Proceed to Test Step 4. Result: The switches and/or circuit breakers are not OK. Repair: Make the necessary repairs. |
4. Starting Motor Solenoid and Starting Circuit A. Test the operation of the starting motor circuit. Refer to Systems Operation, Testing, and Adjusting, "Electrical System" for additional information. |
Starting motor solenoid and circuit |
Result: The starting motor solenoid and circuit are OK. Proceed to Test Step 5. Result: The starting motor solenoid and circuit are not OK. Repair: Make the necessary repairs. |
5. Inspect the Starter Pinion and Flywheel Ring Gear A. Test the operation of the starting motor. B. Check the pinion clearance. Inspect the pinion and the flywheel ring gear for damage. Refer to Systems Operation, Testing, and Adjusting, "Electrical System" for additional information. |
Starter pinion and flywheel ring gear |
Result: The starter pinion and flywheel ring gear are OK. Proceed to Test Step 6. Result: The starter pinion and flywheel ring gear are not OK. Repair: Make the necessary repairs. |
6. Inspect Engine Accessories and the Transmission (if applicable) A. Ensure free movement of the driveline. B. Remove and inspect any engine accessories that may lock up the engine. The following list identifies engine accessories that may lock up the engine: · Hydraulic pump that is driven from the rear gear group · Air compressor · Engine oil pump · Other components that are driven by the engine |
Engine accessories and transmission |
Result: The engine accessories and transmission are OK. Proceed to Test Step 7. Result: The engine accessories and transmission are not OK. Repair: Make the necessary repairs. |
7. Hydraulic Cylinder Lock A. If an injector has been replaced, evacuate any fluids from the cylinder and attempt to start the engine. Fuel will flow from the cylinder head into the cylinders when a unit injector is removed. B. If the engine will not start, check for fluid in the cylinders (hydraulic cylinder lock) by removing the individual unit injectors. Check for damaged seals. Determine the type of fluid that locked up the cylinder. C. If there was a coolant leak, determine the cause of the leak. Check the exhaust (NRS) cooler for leaks. Refer to Testing and Adjusting, "Exhaust Cooler (NRS) - Test". D. If there was excessive fuel in the cylinder, replace the seals and reinstall the injector. Drain any excess fuel from the cylinder head. E. If a mechanical problem is suspected, disassemble the engine. Refer to the Disassembly and Assembly manual. Inspect the internal components for the following conditions: · Seizure · Broken components · Bent components |
Hydraulic cylinder lock |
Result: The engine has a hydraulic cylinder lock. Repair: Make the necessary repairs. Result: The engine does not have a hydraulic cylinder lock. Contact the Dealer Solutions Network (DSN). |
Caterpillar Information System:
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