Case IH 3349 – Engine Control Unit (ECU / EDC): Multiple State Switch

The signal from a multiple state switch (such as a travel direction lever, gear lever, or drive mode switch) is 'not plausible' or has an evaluation error. The controller is receiving conflicting, missing, or out-of-range signals from a switch that is supposed to indicate a specific operating state.

• Case IH Magnum Series 235
• Case IH Magnum Series 260
• Case IH Magnum Series 290
• Case IH Magnum Series 315
• Case IH Magnum Series 340 (Series 4)
• Case IH Steiger Series
• Case IH Axial-Flow Combines

1. 1

   Identify which multiple state switch is triggering the fault (commonly the shuttle lever, travel direction switch, or multi-function handle).

2. 2

   Inspect the wiring harness and connectors between the Multiple State Switch and the Engine ECU for corrosion, backed-out pins, or physical damage.

3. 3

   Perform a signal plausibility check using a multimeter or diagnostic tool (e.g., CNH EASy) to monitor switch states for a short to battery, short to ground, or an open circuit.

4. 4

   Verify CAN bus communication to ensure there are no CAN transmit timeout errors accompanying this code.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical shorts during testing.

2. 2

   Access the Switch

   Remove the interior cab trim or armrest panels required to access the suspected Multiple State Switch (e.g., the shuttle lever or multi-function handle).

3. 3

   Test Continuity

   Disconnect the switch and test the internal contacts with a multimeter. Verify that the switch opens and closes correctly in every physical position (e.g., Forward, Neutral, Reverse).

4. 4

   Harness Pin-Out

   If the switch tests good, perform a continuity test on the wiring harness from the switch connector back to the Engine ECU pins. Repair any broken wires or chafed insulation.

5. 5

   Replace the Switch

   If the switch fails the continuity test or sends erratic resistance values, replace the switch assembly.

6. 6

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic tool to clear the 3349 fault code. Cycle the switch through all its states to ensure the code does not return.