Case IH 3326 – Engine Controller (Engine ECU): Timeout of CAN Message ETC2 (Transmission)

The Engine Control Unit (ECU) has not received the expected Electronic Transmission Controller #2 (ETC2) data message over the Controller Area Network (CAN) bus within the programmed time limit. This indicates a communication failure between the engine and the transmission modules, usually caused by a wiring issue, a dead module, or a corrupted CAN bus network.

• Case IH Magnum 235 - 340 (Series 4)
• Case IH Steiger series
• Case IH Puma and Maxxum series
• Case IH Patriot Sprayers

1. 1

   Check for multiple codes using a diagnostic tool (like CNH EST or Jaltest) to see if other CAN timeout codes are present, indicating a main CAN bus backbone issue rather than a specific module failure.

2. 2

   Verify the Transmission Control Unit (TCU) is receiving proper battery voltage and has a clean ground.

3. 3

   With the key off and battery disconnected, measure the resistance across the CAN High and CAN Low pins at the diagnostic port (should be approximately 60 ohms).

4. 4

   Visually inspect the wiring harness between the Engine ECU and the Transmission Controller for chafing, pinch points, or melted insulation.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable to prevent electrical damage during testing.

2. 2

   Inspect Connectors

   Locate the Engine ECU and the Transmission Controller. Disconnect the main harness connectors at both modules. Inspect the pins for corrosion, moisture ingress, or pushed-back pins. Clean with electrical contact cleaner if necessary.

3. 3

   Test CAN Continuity

   Using a digital multimeter, perform a continuity test on the CAN High and CAN Low wires from the Engine ECU connector to the Transmission Controller connector.

4. 4

   Test for Shorts

   Test the CAN High and CAN Low wires for continuity to ground (chassis) and to power. There should be no continuity.

5. 5

   Repair Wiring

   If an open circuit or short is found, repair the damaged section of the wiring harness. If the harness is heavily corroded or damaged, replace the affected CAN-bus wire harness section.

6. 6

   Check Terminating Resistors

   If the wiring is intact, locate and test the CAN bus terminating resistors. Replace any resistor that does not measure 120 ohms individually.

7. 7

   Reassemble and Clear Codes

   Reconnect all modules and the battery. Connect a diagnostic service tool, clear the inactive fault codes, and cycle the key.

8. 8

   Module Verification

   Start the machine. If code 3326 returns immediately and the wiring/resistors are 100% verified, the Transmission Controller may have an internal CAN transceiver failure and will require a software re-flash or physical replacement.