Possible Causes
• Diagnostic Codes
• Starting Assist Devices
• Load • Battery
• Charging Circuit
• Starter Motor
• Fuel Supply
CAT Comm Adapter3 478-0235 Diagnostics for Caterpillar
1. Check for Relevant Diagnostic Codes
A. Establish communication between the electronic service tool and the ECM. If necessary, refer to Troubleshooting and Repair, "Electronic Service Tools".
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic codes.
Diagnose and eliminate all existing diagnostic codes before continuing this procedure.
Diagnostic Codes
Result: No active or recorded diagnostic codes. Proceed to Test Step 2.
Result: Code is active or recorded.
Repair: Diagnose and eliminate the code before continuing this step.
Refer to Troubleshooting and Repair, "Diagnostic Codes" for troubleshooting and eliminating diagnostic codes.
2. Starting Assist Device
A. If low-temperature conditions exist, check the operation of the starting assist device.
B. Confirm that the starting assist device is operating normally.
Starting Assist Device
Result: The starting assist device is operating normally. Proceed to test step 3.
Result: The starting assist device is not operating normally.
Repair: Refer to the corresponding circuit test for troubleshooting the starting assist device.
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3. Overload
A. Check for excessive load on the engine.
B. If necessary, disconnect the driven equipment and then test the engine again.
Overload
Result: The engine load is too high.
Repair: Reduce the engine load. Return the unit to operation.
Result: There is no excessive load on the engine. Proceed to test step 4.
4. Battery
A. Check if the battery can maintain its charge. Refer to System Operation/Testing and Adjustment, "Battery - Test" for the correct procedures.
Battery
Result: The battery will not retain its charge.
Repair: Replace the battery. Refer to the machine's disassembly and assembly manual for the correct procedures.
Result: The battery retains its charge.
5. Switching the Battery Circuit
A. Check the connections in the battery cables, wiring, and charging circuit.
B. Check the battery circuit discharge when in the ON position.
C. Charge the battery. Confirm that the battery can retain its charge.
6. Alternator
A. Check the condition of the alternator. For the correct procedures, refer to Troubleshooting and Repair,
"Alternator Faults"
Result: The alternator is functioning normally. Proceed to test step 7.
Result: The alternator is not functioning normally.
Repair: Replace or repair the alternator.
Battery Circuit
Result: The battery circuit is functioning normally. Proceed to test step 6.
Result: The battery circuit is not functioning normally. Repair: Clean and tighten all connections. Replace any faulty parts if necessary.
Caterpillar ET 2026A & 2019C Electronic Technician Diagnostic Software Download and Installation
