3412 Generator Set Caterpillar

Engine Does Not Crank

Usage:

3412 DK6

Use this procedure in order to troubleshoot an engine that does not crank.

Probable Causes

Switches
Batteries
Electric starting system (if equipped)
Air starting system (if equipped)
Hydraulic starting system (if equipped)
Flywheel ring gear
Driven equipment
Hydraulic cylinder lock
Rack solenoid alignment
Worn engine components

Recommended Actions

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Table 1
Troubleshooting Test Steps	Values	Results
1. Inspect the Switches A. Check the keyswitch input to the ECM. B. Check engine shutdown switches. C. Connect Cat^® Electronic Technician (ET) to the service tool connector. D. Use Cat ET to verify the status of the following parameters: - Shutdown switches	Switches	Result: The switches are OK. Proceed to Test Step 2. Result: A switch is NOT OK. Repair: Repair or replace damaged switch. If the problem is not resolved, proceed to Test Step 2.
2. Inspect the Batteries A. Charge the batteries, if necessary. Refer to Special Instruction, SEHS7633, "Battery Test Procedure" for additional information. B. Load-test the batteries. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6, 8 V and 12 V Lead Acid Batteries" for additional information.	Batteries	Result: The batteries are OK. Proceed to Test Step 3. Result: The batteries are NOT OK. Repair: Repair or replace the batteries. If the problem is not resolved, proceed to Test Step 3.
3. Check the Electric Starting System A. If the application is equipped with an electric starting system, perform the following procedure: a. Check the wiring to the starting motor solenoid. Refer to the electrical schematic. b. Check the engine start switch and the engine start relay for electrical power. c. Check the starting motor cables. If the starting motor cables are corroded, remove the starting motor cables and clean the starting motor cables. d. Test the operation of the starting motors.	Starter	Result: The electric starter is OK. Proceed to Test Step 6. Result: The electric starter is NOT OK. Repair: Repair or replace damaged electric starter. If the problem is not resolved, proceed to Test Step 6.
4. Check the Air Starting System A. If the application is equipped with an air start system, perform the following procedure: a. Verify that the air start system has an adequate supply pressure for starting. b. Check the wiring to the air start relay that is for the air starting motors. Refer to the applications electrical schematic. c. Check the engine start switch for electrical power. d. Check the air start supply lines. If the supply lines are leaking or damaged, repair the lines. e. Test the operation of the air start motors.	Starter	Result: The air starter is OK. Proceed to Test Step 6. Result: The air starter is NOT OK. Repair: Repair or replace damaged air starter. If the problem is not resolved, proceed to Test Step 6.
5. Check the Hydraulic Starting System A. If the application is equipped with a hydraulic starting system, perform the following procedure: a. Verify that the hydraulic starting system has an adequate supply pressure for starting. b. Check the wiring to the start relay that is for the starting motors. Refer to the applications electrical schematic. c. Check the engine start switch for electrical power. d. Check the hydraulic starting lines. If the supply lines are leaking or damaged, repair the lines. e. Test the operation of the hydraulic starting motors.	Starter	Result: The hydraulic starter is OK. Proceed to Test Step 6. Result: The hydraulic starter is NOT OK. Repair: Repair or replace damaged hydraulic starter. If the problem is not resolved, proceed to Test Step 6.
6. Inspect the Flywheel Ring Gear for Damage	Ring Gear	Result: The flywheel ring gear is OK. Proceed to Test Step 7. Result: The flywheel ring gear is NOT OK. Repair: Repair or replace the ring gear. If the problem is not resolved, proceed to Test Step 7.
7. Inspect the Driven Equipment	Driven Equipment	Result: The driven equipment is OK. Proceed to Test Step 8. Result: The driven equipment is NOT OK. Repair: Repair or replace damaged driven equipment. If the problem is not resolved, proceed to Test Step 8.
8. Check for 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. D. If there was excessive fuel in the cylinder, replace the seals and reinstall the injector. Drain any excess fuel from the cylinder head.	Hydraulic Cylinder Lock	Result: The engine does not have a hydraulic cylinder lock. Proceed to Test Step 9. Result: The engine has a hydraulic cylinder lock. Repair: Perform the necessary repairs. If the problem is not resolved, proceed to Test Step 9.

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Illustration 1	g03868876
(1) Rack solenoid (2) Rack solenoid control lever (3) Fuel rack (4) Fuel rack slot (5) Governor

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Table 2
Troubleshooting Test Steps	Values	Results
9. Inspect the Rack Solenoid Lever Alignment With the Fuel Rack A. Remove the rack solenoid shown in Illustration 1. B. Check for the solenoid lever aligns properly with the slot in the fuel rack.	Rack alignment	Result : The rack solenoid alignment is OK. Proceed to Test Step 10. Result : The rack solenoid alignment is NOT OK. Repair : Refer to Testing and Adjusting, RENR1388, "Fuel System - Finding the Top Center Position for No. 1 Piston" to set the engine. Install the rack solenoid lever into the fuel rack slot. If the problem is not resolved, proceed to Test Step 10.
10. Inspect the Engine for Internal Problems A. If a mechanical problem is suspected, disassemble the engine. Refer to the Disassembly and Assembly manual for additional information. B. Inspect the internal components for the following conditions: - Seizure - Broken components - Bent components	Damaged or Worn Engine Components	Result: There are worn or damaged engine components. Repair: Repair or replace the worn or damaged engine components. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).