Case IH 3255 (DTC E31D) - ECU – Engine Control Unit (ECU / ECM): ECU internal failure - ADC test (Analog to Digital Converter test impulse error)

The Electronic Control Unit (ECU) continuously monitors the efficiency of its internal Analog to Digital Converter (ADC). To do this, a fixed test input voltage is sent to and converted by the ADC. The expected test voltage value must fall between 4.73 V and 4.83 V. The ECU counts each time the value is recorded outside of this specified range. If the error counter exceeds 15 times, the ECU logs fault code 3255.

• MAXXUM T4E
• 240 Series Axial-Flow (7230, 8230, 9230)
• Puma series
• Magnum series (e.g., 235–340 Series 4)
• Steiger
• Quadtrac
• Optum

1. 1

   Verify that no external power supply (e.g., booster or jump box) is connected to the battery

2. 2

   Test the alternator and batteries to ensure the charging system is not overcharging or providing erratic voltage to the ECU

3. 3

   Inspect the main engine wiring harness for shorts to ground or battery, which could back-feed improper voltage into the ECU

4. 4

   Check for faulty solenoids on the engine harness that may be shorting out the ECU's internal circuits

1. 1

   Disconnect External Power

   Remove any external chargers or jump packs.

2. 2

   Clear Codes

   Connect the electronic service tool (EST), clear the fault codes, and cycle the key.

3. 3

   Retest

   Run the engine to see if the code returns.

4. 4

   Replace ECU

   If the code returns immediately and the charging system/harness is verified good, the failure is a hard internal hardware fault (the ADC converter has failed). The Engine Control Unit (ECU) must be replaced.

5. 5

   Reprogram

   Install the new ECU and use the dealer service tool to flash the correct software/calibration file for the specific Engine Serial Number (ESN) and machine model.