Case IH t2D – ECU: Battery Voltage Below Normal

The control module is detecting a voltage supply that has dropped below the minimum acceptable operating threshold, or there is a complete open circuit (break in the wiring) in the battery voltage sensing circuit.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• MX Series
• TG Series

1. 1

   Test Battery Voltage: Use a multimeter to check the resting battery voltage (should be 12.4V to 12.6V) and running voltage (should be 13.5V to 14.5V).

2. 2

   Inspect Terminals and Cables: Check the battery posts, battery isolator switch (if equipped), and main ground connections to the chassis for heavy corrosion, looseness, or fraying.

3. 3

   Check Alternator Output: Verify that the alternator is actively charging the system when the engine is running.

4. 4

   Test ECU/Transmission Controller Power Supply: Pin-test the main power and ground wires at the ECU/Transmission controller harness to ensure the module is actually receiving the voltage that the battery is outputting. Look for voltage drop across the harness.

1. 1

   Disconnect battery

   Turn off the ignition and disconnect the negative battery cable for safety.

2. 2

   Clean battery connections

   Remove the battery cables and thoroughly clean the battery posts and cable terminals with a wire brush. Reattach and tighten them securely to ensure a strong connection.

3. 3

   Repair wiring harness

   If your multimeter testing revealed a voltage drop or open circuit between the battery and the ECU, trace the wiring harness. Splice and repair any broken wires, and clean any corroded multi-pin connectors using electrical contact cleaner.

4. 4

   Replace charging components

   If the battery fails a load test, replace it. If the alternator is not outputting at least 13.5V while the engine is running, replace the alternator or its voltage regulator.

5. 5

   Clear fault codes

   Reconnect all components, start the tractor, and clear the stored fault codes via the H-Menu or a CNH diagnostic tool. Test drive the machine and operate the transmission/EDC to ensure the code does not return.