Yale 51-31 – Vehicle Controller / Engine Control Unit (ECU): Throttle Position Sensor 1 & 2 Out of Range

This fault code indicates that the voltage readings from Throttle Position Sensor (TPS) 1 and 2 are falling outside of their expected operating ranges. The underlying condition is typically caused by an internal sensor failure, an open or shorted wiring harness, physical damage to the throttle body, or a malfunction within the controller failing to correctly process the signals.

• Yale and Hyster Forklifts
• Hyster and Yale forklifts (2005 and newer models)
• Yale Veracitor VX series (GC/GLC/GDP/GLP 030-155VX)
• Hyster Fortis FT series (H30-155FT, S30-120FT)

1. 1

   Inspect the electronic throttle assembly, throttle body, and linkage for dirt, corrosion, mechanical damage, or binding

2. 2

   Inspect the sensor wiring harness and connectors for open circuits, short circuits, corrosion, or physical damage

3. 3

   Use a multimeter or a diagnostic handset (such as Jaltest) to test the sensor output voltages and verify if they are within the correct specified ranges

4. 4

   If the hardware, wiring, and sensor outputs all test normal, test the controller module itself for input processing failures

1. 1

   Clean the Throttle Body

   If mechanical binding or heavy carbon/dirt buildup is found during the visual inspection, clean and lubricate the throttle body and linkage.

2. 2

   Repair Wiring

   If the wiring harness is damaged, corroded, or shorted, repair or replace the affected wiring.

3. 3

   Replace the Sensor/Assembly

   If the sensor outputs incorrect voltage ranges and the wiring is intact, replace the Throttle Position Sensor (or the entire Electronic Throttle Assembly if the sensor is integrated and cannot be serviced separately).

4. 4

   Replace the Controller

   If the throttle body, sensor, and wiring are all in good working order but the code persists, replace the controller module.

5. 5

   Clear Codes

   After the repair is complete, use a diagnostic tool to clear the permanent or pending fault codes from the system and verify that the code does not return during operation.