Yale 524230-4 – Vehicle System Manager (VSM) / Main Controller: Rear Work Lights Relay (RL7) Driver Output OORL

Output driver feedback voltage is lower than expected when the circuit is commanded ON by the system.

• Yale and Hyster Forklifts
• Yale and Hyster forklifts (2005 and newer)
• Yale Veracitor VX series (e.g., GLP040VX, GLC080VX, GC135VX)
• Hyster Fortis FT series

1. 1

   Hard Reset: Turn the forklift's power to OFF for no less than 30 seconds, and then turn it back to ON to attempt to clear the displayed DTC. If the code does not reoccur, resume operation.

2. 2

   Visual Inspection: Conduct a quick visual inspection of all connectors and wiring associated with the rear work lights and the PDM. Look for pinched wires, exposed copper, or melted connectors.

3. 3

   Relay Coil Test: Ensure truck power is OFF. Open the cover on the PDM and remove the RL7 relay. Using a Digital Multimeter (DMM) set to the ohms scale, measure the resistance between the coil terminals of the relay. Note: The typical resistance value of a standard 12-volt relay coil is between 80 and 200 ohms. If the resistance is less than 0.5 ohms, the relay coil is shorted.

1. 1

   Power Down

   Turn the forklift off and disconnect the battery to ensure safety.

2. 2

   Access the PDM

   Open the Power Distribution Module panel and locate the RL7 (Rear Work Lights) relay.

3. 3

   Test/Replace the Relay (Cause A)

   If your DMM test (from the diagnostic steps) showed less than 0.5 ohms of resistance across the coil terminals, the relay is shorted. Replace the RL7 relay with a new one.

4. 4

   Check Wiring (Cause B)

   If the relay tests within the normal 80-200 ohm range, the issue is likely in the wiring. Trace the wiring harness from the PDM relay driver output to the rear work lights and the controller. Look for a short to ground. Repair or replace any damaged wire segments.

5. 5

   Controller Replacement (Cause C)

   If the relay is perfectly fine and the wiring harness shows no shorts to ground, the fault lies in a functional failure of the VSM/Controller. The controller will need to be replaced and reprogrammed by a certified dealer.

6. 6

   Reassembly

   Reinstall all removed components, reconnect the battery, turn the key ON, and verify that the fault code has cleared.