Yale 522592-0 – Engine ECU / Controller: EPR Pressure Greater Than Commanded

The Electronic Pressure Regulator (EPR) or Fuel Delivery Electronic Pressure Regulator (DEPR) is detecting a fuel pressure that is higher than what the engine controller is requesting. This condition typically results in the engine running rich, which can cause rough idling and a strong sulfur smell from the exhaust. The underlying causes are usually a worn or damaged primary or secondary seat within the regulator, faulty electrical connections to the EPR, or a complete internal failure of the EPR itself.

• Yale and Hyster Forklifts
• Hyster and Yale forklifts (2005 and newer)
• Yale Veracitor (VX) series
• Hyster Fortis (FT) series
• Yale GLP060VX
• Yale GLC050VX
• Yale GLP040VX
• Yale GLC100VX

1. 1

   Power Cycle: Turn the forklift's power to OFF for no less than 30 seconds, and then turn it back to ON to clear the displayed DTC. Check if the code reoccurs.

2. 2

   Visual Inspection: Conduct a visual inspection of all connectors and wiring associated with the EPR/DEPR.

3. 3

   Connector Integrity: Ensure the electrical connection to the EPR is physically secure (i.e., sockets and pins are seated correctly, and the connector 'clicks' to indicate the locking tab works correctly).

4. 4

   Wiring Damage: Check for any damaged wiring or shorts in the harness that could be causing a false reading.

1. 1

   Locate the EPR

   The EPR is typically located in the LP fuel line system, often directly behind the mixer/vaporizer closer to the fan. It is identifiable by a multi-pin electrical connector.

2. 2

   Determine Repair vs. Replace

   Because a brand-new EPR assembly can be expensive, many technicians opt to rebuild the regulator.

3. 3

   Rebuild the EPR

   If rebuilding, remove the EPR from the fuel system and use an EPR minor repair kit to replace the internal seats and diaphragms (the section of the EPR that the fuel runs through).

4. 4

   Replace the EPR/Mixer

   If a rebuild is not possible or fails, replace the entire EPR, mixer, or vaporizer assembly.

5. 5

   Clear Codes

   After the repair, the code should clear itself once the over-pressure condition is resolved, though a power cycle may be required.