Case IH 3373 – Engine Control Module (ECM) / EDC: Injection Quantity Adjustment failure - EEPROM Adjustment Value Not Readable

The Engine Control Module has lost or cannot read the specific calibration codes (IQA/IMA codes) for the fuel injectors from its internal EEPROM memory. These codes tell the ECU how to adjust the fuel delivery duration for each specific injector to ensure smooth engine operation. When the EEPROM cannot read these values, the engine may run poorly, derate, or fail to meet emissions standards.

• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 315
• Magnum 340
• Magnum 370 (Series 4)
• Steiger series
• Puma
• Optum
• Axial-Flow (AF) 6130
• Axial-Flow (AF) 7130
• Axial-Flow (AF) 7230

1. 1

   Verify Injector Codes: Connect the CNH Electronic Service Tool (EST) or a compatible heavy-duty diagnostic scanner. Navigate to the Engine Controller and check the programmed injector IQA/IMA codes.

2. 2

   Physical Inspection: Remove the engine valve cover or inspect the exposed injector bodies (depending on engine model) to read the alphanumeric calibration codes physically printed on the top or side of each fuel injector.

3. 3

   Compare Values: Check if the codes in the ECU are blank, corrupted, or mismatched with the physical injectors.

4. 4

   Check ECU Power/Grounds: Ensure the Engine ECU is receiving stable voltage. Voltage drops or spikes can sometimes cause EEPROM memory corruption.

1. 1

   Read Physical Codes

   Write down the exact Injection Quantity Adjustment (IQA) code printed on each of the engine's fuel injectors, noting which cylinder each code belongs to.

2. 2

   Connect Diagnostic Tool

   Connect the CNH EST to the machine's diagnostic port.

3. 3

   Reprogram the ECU

   Navigate to the Engine Controller programming/calibration menu. Manually enter the correct IQA values for each cylinder into the software.

4. 4

   Save to EEPROM

   Save the configuration to the Engine ECU's EEPROM.

5. 5

   Cycle Power

   Turn the ignition key off, wait 30-60 seconds for the ECU to power down completely, then turn the ignition back on.

6. 6

   Clear Codes

   Clear the 3373 fault code and start the engine.

7. 7

   ECU Replacement (If Necessary)

   If the diagnostic tool cannot write to the ECU, or if the 3373 code returns immediately after a key cycle, the Engine ECU has suffered an internal EEPROM hardware failure. The EDC unit must be replaced and flashed with the correct machine software and injector codes.