Case IH 55 – Transmission ECM: FORWARD_SW_HI_ERR (57 Auto None)

Power Shuttle FNR (Forward/Neutral/Reverse) Lever Forward Position Switch Short to 5 or 12 Volts. The module logs this code when it detects that the voltage is abnormally high (above 4.2 volts) at ECM connector 2, pin 26.

• JXC
• JX Series
• JXU Series
• JX70U
• JX100U
• Quantum Series
• Farmall series
• Maxxum MX Series
• TN Series
• TNA Series
• TN60A
• TN70A
• TN75A
• T4000 Series

1. 1

   Inspect the wiring harness running down the steering column from the FNR lever to the Transmission ECM for chafed wires, pinched harnesses, or melted insulation that could cause a short to power.

2. 2

   Back-probe the Transmission ECM at Connector 2, Pin 26 to verify if the voltage is resting above 4.2 volts.

3. 3

   Disconnect the FNR switch and test the harness side for a short to 12V (between ECM connector 2, pin 20 and the switch) or a short to 5V/12V on the signal wire (pin 26).

4. 4

   Test the FNR switch terminals directly with a multimeter to see if the forward position contacts are internally shorted to the reference voltage.

1. 1

   Disconnect Power

   Disconnect the negative battery cable to prevent electrical spikes or accidental shorts during the repair.

2. 2

   Access the Switch

   Remove the plastic steering column console wrapper/shrouds to expose the FNR shuttle lever assembly mounted on the left side of the steering column.

3. 3

   Disconnect Wiring

   Take a photo of the wire routing, then unplug the multi-pin sealed connector plug socket connecting the FNR switch to the main harness.

4. 4

   Remove the Faulty Switch

   Remove the mounting hardware securing the FNR lever assembly to the steering column bracket and slide the old unit out.

5. 5

   Install the New Part

   Mount the replacement FNR lever assembly into position and secure it with the mounting hardware.

6. 6

   Reconnect

   Plug the multi-pin connector firmly into the new switch socket. Ensure the wiring is routed safely away from moving steering components.

7. 7

   Reassembly

   Reinstall the steering column shrouds.

8. 8

   Testing

   Reconnect the battery. Turn the key on and test the Forward-Neutral-Reverse shuttle operation to ensure the fault code is cleared and directional shifts engage smoothly without hesitation.