Case IH 19002 (F-168-04) - ECU – ECU: Battery voltage sensing (electrical) – signal low – Battery voltage evaluation below lower limit

This condition is triggered when the control unit monitors the system's battery voltage and determines that the voltage has dropped below the minimum acceptable operating threshold (typically below 10.2 V).

• VESTRUM CVX
• Magnum Series (235–340 Series 4)
• Steiger Series (350–600)
• Farmall Series (115U)
• Puma Series
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• A8000 Sugarcane Harvester
• A8800 Sugarcane Harvester
• A9900 Sugarcane Harvester

1. 1

   Verify Active Status: Use the Electronic Service Tool (EST) to check if the fault is currently active. If it is inactive, the voltage drop may have been a temporary event (e.g., heavy cranking in cold weather).

2. 2

   External Power Check: Ensure the tractor's battery power supply has not been improperly connected to an external power supply or jump-starter. If it is, disconnect it and test the system for normal operation.

3. 3

   Battery Load Test: Test the physical batteries to ensure they can hold a charge above 10.2 V under load.

4. 4

   Wiring Harness Inspection: Inspect the power supply wiring leading directly to ECU A-095. Look for corrosion, loose ground connections, or chafed wires that could cause a voltage drop between the battery and the module.

5. 5

   Alternator Output: Verify that the alternator is properly charging the batteries when the engine is running.

1. 1

   Charge or Replace Batteries

   If the battery voltage is genuinely below 10.2 V and fails a load test, replace the batteries as a pair (never replace just one battery in a dual-battery setup, as the alternator will overcharge the new one).

2. 2

   Clean Connections

   Clean all battery terminals, the main chassis ground, and the battery isolator switch connections to eliminate high-resistance points.

3. 3

   Repair ECU Wiring

   If the batteries are healthy but the ECU is still reading low voltage, trace the power supply circuit to ECU A-095. Repair or replace any damaged sections of the wiring harness.

4. 4

   Reinstall/Replace ECU

   If the wiring and batteries are perfectly healthy but the ECU internally fails to read the correct voltage, the service manual dictates to first attempt to reinstall/reflash ECU A-095. If it still fails, the ECU itself must be replaced.

5. 5

   Clear Codes

   Use the EST to clear the fault code and run the machine to verify the repair.