Case IH t2E – Transmission / EDC (Electronic Draft Control) Controller and Engine ECU (PCU): Battery Voltage, Shorted To Low Source.

The control module is detecting that the battery voltage supply to the ECU has fallen below the minimum acceptable operating threshold (typically <7.2V) or the power supply circuit is physically shorted to ground (the "low source").

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

1. 1

   Measure voltage directly at the battery terminals (should read approximately 12.6V resting and 14.0V running)

2. 2

   Inspect battery terminals, chassis grounds, and ECU ground connections for heavy corrosion, looseness, or broken straps

3. 3

   Test main power relay and transmission/PTO relay modules for voltage drops across the contacts

4. 4

   Trace the wiring harness from the battery and main relays to the ECU/Transmission controller for chafed insulation or shorts to ground

5. 5

   Verify the alternator is charging correctly and not allowing system voltage to drain

1. 1

   Disconnect Power

   Disconnect the negative battery terminal to ensure safety while working on the electrical system.

2. 2

   Clean Connections

   Thoroughly clean the battery posts, terminals, and the main chassis ground connection. Reattach and tighten them to spec.

3. 3

   Repair Wiring

   If the harness inspection revealed chafed wires shorting to the frame, cut out the damaged section, solder in a new piece of wire, and seal it with heat-shrink tubing. Secure the harness away from sharp metal edges using zip ties or loom clamps.

4. 4

   Replace Relays

   If the main power relay or transmission relay is corroded or failing under load, replace it with a new OEM relay.

5. 5

   Clear Codes & Calibrate

   Reconnect the battery. Turn the key switch to the "ON" position to verify if the code clears. Note: According to the MXM Series Calibration Guide, if the transmission controller memory was reset or power was lost, a transmission calibration may be required. This involves holding the High and Low range buttons while starting the engine, setting engine speed to 1200 RPM, and following the display prompts until "END" appears.