Yale 880-4 – VSM (Vehicle System Manager): Stop Lamp Driver Output OORL (Out Of Range Low)

The system has detected that the voltage/signal for the stop lamp (brake light) circuit is lower than expected. This is typically caused by the lamp driver output shorting to ground, a functional failure within the controller, a burned-out brake light bulb, or a blown fuse.

• Yale and Hyster Forklifts
• Yale VX Series (GLC040SVX, GLC050VX, GLP/GDP series)
• Yale ERP16VT
• Hyster FT Series (S30FT, H5.0FT, Fourtens)

1. 1

   Inspect the rear stop lamp (brake light) bulbs to see if a bulb is burned out.

2. 2

   Inspect the fuse box for a blown 20-amp fuse associated with the lighting/chassis circuit.

3. 3

   Test the wiring harness by locating the VSM controller, identifying the stop lamp output wire (Wire #788 at Pin 7), and measuring its resistance to ground. Less than 0.5 ohms indicates a short to ground.

1. 1

   Bulb/Fuse Replacement

   If a bulb is burned out or a fuse is blown, replace the component, clear the codes, and test the brake lights.

2. 2

   Harness Repair

   If your multimeter shows less than 0.5 ohms on Wire #788, physically trace the wire from the VSM to the rear tail lights. Look for pinched wires, rubbed insulation, or corrosion shorting the wire to the forklift's frame, and repair the damaged section.

3. 3

   VSM Replacement

   If the bulbs are good, the fuse is intact, and the wiring harness tests fine (no short to ground), the VSM itself has suffered an internal functional failure. Replace the VSM. Note that a new VSM comes unprogrammed and requires dealer software calibration.