Case IH 2074 (519374.17) - DEC – Transmission (Trans) ECU: FNR Not Park Switch low voltage fault

The Transmission controller is detecting that the voltage from the Forward/Neutral/Reverse (FNR) shuttle lever position sensor has dropped below the acceptable threshold, typically caused by the switch input being shorted to ground or having an open circuit.

• MAXXUM T4E
• Case IH Magnum 235 – 340 (Series 4)
• CASE STX Steiger tractors (350 to 600 HP)

1. 1

   Inspect the wiring harness connecting the FNR pod/switch to the Transmission ECU for any open circuits, chafing, or a short to ground.

2. 2

   Test the voltage at the FNR lever position sensor to confirm if it is receiving proper power or if the voltage is dropping out.

3. 3

   Swap in a known good FNR switch (or an older backup switch) temporarily to see if the tractor shifts normally and the code clears.

1. 1

   Park and disconnect battery

   Park the tractor on a level surface, turn off the engine, and disconnect the battery.

2. 2

   Remove steering wheel

   Remove the steering wheel to gain access to the steering column assembly.

3. 3

   Remove steering column covers

   Take off the steering column covers.

4. 4

   Disconnect wiring harness

   Locate the gear selector/FNR switch assembly and disconnect its wiring harness.

5. 5

   Remove old gear selector

   Unbolt and remove the old gear selector assembly from the column.

6. 6

   Install new FNR switch

   Install the new FNR switch assembly and reconnect the wiring harness securely.

7. 7

   Reinstall covers and steering wheel

   Reinstall the steering column covers and the steering wheel.

8. 8

   Test operation

   Reconnect the battery, start the tractor, and test the shuttle shift lever in Forward, Neutral, Reverse, and Park to ensure the transmission engages properly and the fault code is cleared.