Case IH 3890 – Engine Control Module (ECM) / Electronic Diesel Control (EDC): SPI communication Chip 2 defective

Indicates a hard internal hardware failure or communication breakdown specifically with 'Chip 2' on the control module's internal circuit board.

• Equipment with FPT engines utilizing EDC Tier 3 and Tier 4a
• NEF 4-cylinder engines
• NEF 6-cylinder engines

1. 1

   Check system voltage: Verify battery voltage and alternator output. Severe voltage spikes or extreme low-voltage conditions can sometimes cause microprocessors to temporarily lose SPI communication.

2. 2

   Inspect ECM power and ground: Inspect the main power and ground harness connections at the Engine ECM. Look for corrosion, loose pins, or frayed wires that could cause intermittent power loss.

3. 3

   Clear and retest: Connect the CNH Electronic Service Tool (EST) or a compatible heavy-duty scanner, clear the inactive/active codes, and cycle the key.

4. 4

   Determine hard failure: If code 3890 immediately returns upon key-on or engine cranking, the internal chip failure is permanent, and the ECM must be replaced.

1. 1

   Disconnect Power

   Disconnect the machine's battery (negative cable first) to prevent electrical arcing.

2. 2

   Locate the ECM

   Locate the EDC/ECM, which is typically isolation-mounted directly to the side of the FPT engine block.

3. 3

   Remove Harnesses

   Carefully release the locking levers on the main engine wiring harness connectors and unplug them from the ECM.

4. 4

   Remove the Module

   Remove the mounting bolts securing the ECM to the engine block and remove the defective unit.

5. 5

   Install the New Module

   Mount the replacement ECM and torque the mounting bolts to OEM spec.

6. 6

   Reconnect

   Reconnect the wiring harnesses, ensuring the locking levers seat fully. Reconnect the battery.

7. 7

   Programming

   Connect the CNH Electronic Service Tool (EST) to the machine's diagnostic port and flash the new ECM with the correct engine dataset/software calibration specific to the machine's serial number (PIN).