Case IH 3741 – ENGINE ECU / EDC (Electronic Diesel Control): EDC - Power stages, Injector: Wrong set response time

The engine control module utilizes a safety monitoring concept (MoCSOP) to verify that the fuel injection system is operating correctly. Code 3741 triggers when the ECU detects that the electrical response time of the internal power stage (the circuit responsible for sending high voltage/current to fire the fuel injectors) is incorrect or out of expected parameters. While it is primarily an internal ECU failure, it can occasionally be provoked by severe electrical shorts in the injector circuit.

• Farmall
• Farmall Series
• Farmall 115U Pro EP
• 240 Series Combines
• Machines utilizing FPT F5H, Cursor 9, and similar Tier 4 / Stage V engines

1. 1

   Verify battery voltage and alternator charging output to rule out undervoltage or overvoltage conditions

2. 2

   Inspect the engine wiring harness connecting the EDC to the fuel injectors for chafing, melted wires, or pinch points

3. 3

   Disconnect the EDC and injector connectors to inspect for moisture, corrosion, or bent pins

4. 4

   Ohm-test the fuel injector solenoids to check for internal shorts that could overload the EDC's power stage

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to protect the electrical system.

2. 2

   Isolate the Circuit

   Disconnect the engine wiring harness from both the EDC and the fuel injectors.

3. 3

   Test Wiring & Injectors

   Using a digital multimeter, test the harness for continuity and shorts. Test the resistance of each fuel injector against OEM specifications.

4. 4

   Repair External Faults (If Found)

   If a shorted wire or faulty injector is found, replace the damaged harness or injector. Reconnect the system, clear the codes, and test run the engine.

5. 5

   Replace the EDC

   If the wiring harness and injectors test perfectly fine, the fault is a confirmed internal hardware failure of the EDC's injector power stage. Replace the EDC.

6. 6

   Program the New EDC

   Install the replacement EDC. A certified dealer technician must use the CNH Electronic Service Tool (EST) to flash the new module with the correct software payload for your specific machine.

7. 7

   Final Verification

   Clear all inactive codes and run the machine under load to ensure the fault does not return.