Case IH 3743 – Engine Control Unit (ECU) / Electronic Diesel Control (EDC): EDC Internal Failure (Injectors Power Stage) - Error In Undervoltage Monitoring

The engine controller has run a diagnostic fault check and detected an internal hardware or software anomaly. Specifically, the internal power stage circuitry responsible for firing the fuel injectors is registering an undervoltage condition.

• Farmall
• skid steer
• SR/SV Series
• TR/TV Series
• SR175
• 105N
• 110C
• 115U
• Maxxum
• Steiger
• 240 Series Axial-Flow Combines
• 580ST
• 590SN

1. 1

   Verify the main battery voltage is within the normal operating range (12V or 24V, depending on the machine) under load.

2. 2

   Inspect the main engine wiring harness connecting to the EDC. Look for chafing, corrosion, or damaged pins that could cause a voltage drop to the controller.

3. 3

   Verify all ground connections to the EDC are clean and tight.

4. 4

   Test the main power relays feeding the EDC to ensure they are not sticking or suffering from high internal resistance.

1. 1

   Disconnect Power

   Disconnect the machine's battery to prevent electrical arcing or further module damage.

2. 2

   Remove the EDC

   Carefully disconnect the multi-pin wiring harness connectors from the faulty EDC. Unbolt the module from its mounting bracket on the engine block or firewall.

3. 3

   Install the New EDC

   Mount the replacement EDC and secure the bolts. Reconnect the wiring harnesses and the battery.

4. 4

   Restore Self-Learning Parameters

   A certified technician must connect the Case IH Electronic Service Tool (EST) laptop to the machine to restore self-learning parameters.

5. 5

   Programming

   Use the EST to flash the correct machine software to the blank EDC, input the injector trim codes, and run the automated procedure to restore the engine's self-learning parameters.