Yale 652-5 – Engine Control Module (ECM) / Powertrain Control Module (PCM): GM Gas Drive Injector 2 Open Circuit

The engine's control module has detected a break or interruption in the electrical circuit for the #2 cylinder fuel injector. The controller is not detecting the expected voltage or current draw when it attempts to pulse the injector.

• Yale and Hyster Forklifts
• Yale VX series (GC040-070VX, GLP040-070VX)
• Hyster FT series

1. 1

   Visual Inspection: Inspect the wiring harness and the electrical connector at the #2 fuel injector. Look for chafed wires, broken connections, bent pins, or corrosion.

2. 2

   Injector Resistance Test: Disconnect the electrical plug from the #2 injector and measure the resistance across the injector's pins using a multimeter. If the reading is infinite (OL), the injector coil is burned out and the injector must be replaced.

3. 3

   Voltage Check: Turn the ignition to the ON position (engine off). Check for battery voltage (12V) at the supply wire of the injector connector.

4. 4

   Pulse Test (Noid Light): Plug a noid light into the injector connector and crank the engine. If the light flashes, the ECM and wiring are functioning properly, meaning the injector itself is faulty. If it does not flash, the issue lies in the wiring harness or the ECM.

5. 5

   Continuity Test: Test the continuity of the ground/control wire from the injector connector back to the corresponding pin on the ECM. If the wire is intact and the injector tests good, the ECM's internal injector driver has likely failed.

1. 1

   Disconnect battery

   Disconnect the battery ground cable to ensure safety and prevent electrical shorts.

2. 2

   Relieve fuel pressure

   Relieve the fuel system pressure. For LPG trucks, close the valve on the LP tank and run the engine until it stalls to empty the lines.

3. 3

   Locate injector

   Locate the #2 fuel injector on the engine intake manifold.

4. 4

   Disconnect connector

   Disconnect the electrical connector from the injector.

5. 5

   Repair wiring

   If the diagnostic checks pointed to a wiring issue, repair the broken wire or splice in a new connector pigtail using high-temperature insulation and soldered connections.

6. 6

   Access faulty injector

   If the injector is faulty, remove the fuel rail retaining bolts and gently lift the rail to access the injector.

7. 7

   Remove injector

   Remove the retaining clip and pull the faulty injector out of the manifold/rail.

8. 8

   Lubricate O-rings

   Lubricate the O-rings on the new injector with a small amount of clean engine oil or O-ring grease to prevent tearing.

9. 9

   Install new injector

   Seat the new injector into the manifold and fuel rail, reinstall the retaining clip, and bolt the fuel rail back down.

10. 10

    Reconnect connector

    Reconnect the electrical connector to the injector.

11. 11

    Check for leaks

    Reconnect the battery, open the LP fuel valve (or prime the gas system), and turn the key ON to check for leaks.

12. 12

    Clear fault code

    Start the engine and use a diagnostic handset/software to clear the 652-5 fault code.