823686A 2 Mercury DIGITAL DIAGNOSTIC TESTER

Recommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 1
Troubleshooting Test Steps    Values    Results    
1. Diagnostic Codes
A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM).
B. Monitor the diagnostic codes on Cat ET. Check for active diagnostic codes. Specifically check for codes related to the engine starting system.
Note: Wait at least 30 seconds in order for diagnostic codes to become active.
   
Active Diagnostic Codes
   
Result There are no active codes.
Proceed to Test Step 2.
Result There are active codes.
Repair: Troubleshoot any codes before continuing with this procedure.
Verify that the repair eliminated the problem.
   
2. 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".
D. 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 are OK
   
Result The batteries and cables are OK.
Proceed to Test Step 3.
Result The batteries and cables are not OK.
Repair: Make the necessary repairs.
Verify that the repair eliminated the problem.
   
3. Switches and/or Circuit Breakers (if applicable)
A. If equipped, check the crank enable switch and any other switches and/or circuit breakers that may interfere with the engine cranking. Refer to the applications electrical schematic for additional information.
   
Switches and/or circuit breakers are OK
   
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.
Verify that the repair eliminated the problem.
   
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 are OK.
   
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.
Verify that the repair eliminated the problem.
   
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 are OK
   
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.
Verify that the repair eliminated the problem.
   
6. Inspect Engine Accessories and the Transmission (if applicable)
A. Ensure free movement of the driveline.
B. Remove any engine accessories that may lock up the engine and inspect any engine accessories that may lock up the engine.
The following list illustrates examples of 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 are OK
   
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.
Verify that the repair eliminated the problem.
   
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.
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 hydraulic cylinder lock.
Repair: Make the necessary repairs.
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).