New Holland ENG 3347 – Engine Control Unit (ECU): Multiple State Switch

The engine controller is receiving an invalid signal from the Multiple State Switch. Depending on the FMI, this indicates a short circuit to battery (FMI 3), short circuit to ground (FMI 4), or an invalid/implausible signal (FMI 12).

• T7 series (T7030, T7040, T7050, T7060)
• T8.xxx Series
• CR9090
• CX8080 Elevation
• CX8090 Elevation (Tier 4A)
• Magnum 235 - 340 (Series 4)

1. 1

   Verify the FMI Code: Use a diagnostic tool (like the CNH EASy tool) to determine the exact FMI extension (3, 4, or 12) to narrow down whether you are looking for a short to power, a short to ground, or a mechanical switch failure.

2. 2

   Inspect the Wiring Harness: Check the wiring between the Engine ECU and the Multiple State Switch.

3. 3

   Check for Plausibility: If the code is FMI 12 (Signal not plausible), the switch itself may have internal wear causing it to send conflicting voltage signals to the ECU.

4. 4

   Test the Switch: Disconnect the switch and use a multimeter to verify the resistance values across its different states (e.g., Economy mode, Mode 1, Mode 2, Mode 3).

1. 1

   Power Down

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

2. 2

   Locate the Switch

   Locate the Multiple State Switch, which is typically found on the operator's armrest console or integrated into the multi-function handle.

3. 3

   Inspect Connectors

   Disconnect the switch harness. Inspect the pins on both the switch side and the harness side for corrosion, pushed-out pins, or moisture ingress.

4. 4

   Perform Continuity Testing

   Using a multimeter, test the wiring from the switch connector back to the Engine ECU pins for continuity, and ensure there is no continuity to ground (if FMI 4 is present) or to a 12V power source (if FMI 3 is present).

5. 5

   Replace or Repair

   If the wiring harness is chafed or shorted, repair the damaged section. If the wiring tests good, the Multiple State Switch itself has failed internally and must be replaced.

6. 6

   Clear Codes

   Reconnect the battery, install the new switch, turn the key to the ON position, and use a diagnostic tool to clear the inactive ENG 3347 fault code.