Yale 522595-12 – Engine Control Module (ECM) / Engine Control Unit (ECU): Internal Circuity Fault Detection - Electronic Pressure Regulator (EPR) Actuator Problem

The controller has detected an internal circuit failure or actuator failure within the EPR/DEPR unit itself.

• Yale and Hyster Forklifts
• Veracitor series
• MX series
• GLC030-040VX
• GLP/GP040-070MX
• GLP/GP040-070VX

1. 1

   Check Yale Axcess Online for any electrical system updates or service bulletins related to the DEPR, as software updates can sometimes resolve erroneous codes.

2. 2

   Visually inspect the EPR/DEPR wiring harness and the multi-pin connector for frayed wires, corrosion, or loose pins.

3. 3

   Measure the voltage and resistance at the DEPR connector to rule out an open circuit, short to ground, or short to battery in the main engine harness.

4. 4

   If the wiring harness tests good and the connector is secure, verify that the fault lies within the internal circuitry of the EPR actuator itself.

1. 1

   Safety First

   Turn off the forklift, close the valve on the LPG tank, and run the engine until it stalls to depressurize the fuel lines. Disconnect the battery.

2. 2

   Disconnect the EPR

   Unplug the multi-pin electrical connector from the Electronic Pressure Regulator.

3. 3

   Remove the Faulty Unit

   Disconnect the LPG inlet and outlet hoses/fittings from the EPR. Unbolt the EPR from its mounting bracket.

4. 4

   Install the New EPR

   Mount the replacement Electronic Pressure Regulator. Reconnect the LPG lines, ensuring all fittings are tight and sealed properly to prevent leaks.

5. 5

   Reconnect Electricals

   Plug the multi-pin connector into the new EPR. Reconnect the battery.

6. 6

   Test for Leaks and Clear Codes

   Slowly open the LPG tank valve and use a soapy water solution to check for gas leaks at the fittings. Turn the key on, clear the fault codes via the dash/software, and start the engine to verify smooth operation and ensure the code does not return.