Possible Causes
• Charging Circuit
• Battery
• Auxiliary Devices
Recommended Actions
Follow the steps listed above in order.
Troubleshooting and Testing Steps
CAT Comm Adapter3 478-0235 Diagnostics for Caterpillar
1. Charging Circuit
Result: Charging circuit malfunction.
A. Check if the battery charging circuit is working properly. Refer to Troubleshooting, "Alternator Failure".
Repair: Repair the charging circuit if necessary.
Result: Charging circuit is normal. Proceed to test step 2.
2. Battery
A. Confirm that the battery can no longer hold its charge. Refer to System Operation/Testing and Adjustment, "Battery - Test".
Result: One battery is malfunctioning.
Repair: Replace the faulty battery. Refer to the Operation and Maintenance Manual.
Result: Battery is normal. Proceed to test step 3.
12.2021 Caterpillar ECM ECU Flash Files Full Set Download
3. Auxiliary Devices
A. Check if the battery is being drained because the auxiliary device is constantly on.
Result: The battery was drained because the auxiliary device was constantly on.
Repair: Charge the battery. Verify that the battery can maintain its charge. Refer to system operation/testing and adjustment for the correct procedure.
Result: The auxiliary device was constantly on, but the battery was not drained.
Please contact the Dealer Solutions Network (DSN).
Caterpillar ET 2026A & 2019C Electronic Technician Diagnostic Software Download and Installation
