Yale 522617-5 – Engine ECU: Throttle Not at Fully Closed/Open Position (GM Engines Only)

The engine control system has detected that the electronic throttle mechanism is failing to reach its commanded fully open or fully closed physical limits. This is typically caused by a sticky throttle mechanism, carbon/fuel residue buildup, or a failing electronic throttle body.

• Yale and Hyster Forklifts
• Yale Veracitor VX series (e.g., GLC020-050VX, GC080-120VX, GLP40VX5)
• Hyster Fortis FT series (e.g., S40-70FT, H90-120FT)
• GM 2.4L engines
• GM 4.3L engines

1. 1

   Power Cycle: Turn the forklift power to OFF for no less than 30 seconds, and then turn it back to ON to clear the displayed DTC. If the code does not reoccur, the problem is not verified and you can resume operation. If it does reoccur, proceed to the next step.

2. 2

   Visual Inspection: Conduct a quick visual inspection of all connectors and wiring associated with the electronic throttle body. Look for damaged wiring, pushed-back pins, or loose connections and repair/replace as necessary.

3. 3

   Operational Check: Check for proper operation of the throttle body and the ECU mechanism by exercising the accelerator pedal with the vehicle in neutral.

4. 4

   Operational Check (GM 2.4L): The engine should idle at 775 to 825 rpm with no pedal and continue to the governor speed of 2675 to 2725 rpm at full pedal.

5. 5

   Operational Check (GM 4.3L): The engine should idle at 725 to 775 rpm with no pedal and continue to the governor speed of 2375 to 2425 rpm at maximum full pedal.

6. 6

   Mechanism Cleaning: If the throttle mechanism is not operating smoothly or tracking with accelerator operation, ensure the truck power is OFF and clean any fuel residue or carbon buildup from the mechanism. If cleaning does not resolve the sticky mechanism, the electronic throttle body must be replaced.

1. 1

   Disconnect battery

   Ensure the forklift is turned off and the battery is disconnected.

2. 2

   Remove air intake

   Remove the air intake hose/components to access the electronic throttle body.

3. 3

   Disconnect electrical connector

   Disconnect the electrical connector from the throttle body.

4. 4

   Remove throttle body

   Unbolt and remove the faulty throttle body from the intake manifold.

5. 5

   Install new throttle body

   Clean the mating surface and install the new electronic throttle body with a new gasket. Secure the mounting bolts to OEM torque specifications.

6. 6

   Perform relearn procedure

   After installing the new throttle body, leave the electrical connector unplugged. Turn the machine on and perform a "reset to default" in the dash display. Turn the machine off for 30 seconds, then connect the throttle body plug. Turn the machine back on; the throttle should now be calibrated and function correctly.