Yale 654-5 – Engine Control Module (ECM) / Engine Controller: Injector Solenoid Driver Cylinder 4 Circuit - Current Below Normal or Open Circuit

The controller has detected high resistance or no current at the cylinder 4 injector driver or return pin. This is typically caused by a fuel injector open circuit, an injector driver module failure, or a functional failure in the controller. When this code is active, the engine will likely misfire or run rough.

• Yale and Hyster Forklifts
• Yale VX Series (GLC70VX, 190VX)
• Hyster FT Series (H1.6FT, H1.8FT, H2.0FTS, H30FT, H35FT, H40FTS, S2.0-3.5FT, S40-70FT, S135FT, S155FT)

1. 1

   Check for continuity between the cylinder 4 injector socket and the ECM socket

2. 2

   Inspect the wiring harness for high resistance or broken wires at the cylinder 4 injector driver and return pins

3. 3

   Test the cylinder 4 fuel injector coil for an internal open circuit

4. 4

   If wiring and injector test good, verify if the fault is a functional failure within the ECM/Injector Driver Module

1. 1

   Safety First

   Disconnect the battery cables before doing any disassembly or repair of the engine or parts of the electrical system to prevent damage to the diodes and electrical components.

2. 2

   Access the Injector

   Locate the cylinder 4 fuel injector on the Cummins QSB 3.3L engine and disconnect its electrical harness connector.

3. 3

   Test the Injector

   Measure the resistance across the injector terminals. If the circuit is open (infinite resistance), the fuel injector has failed and must be replaced.

4. 4

   Test the Harness

   If the injector is good, use a multimeter to check the wiring harness from the injector connector back to the ECM for open circuits, shorts to ground, or high resistance. Repair or replace the wiring harness if damage is found.

5. 5

   Address the ECM

   If both the injector and the wiring harness pass inspection, the ECM has suffered a functional failure. Replace the Engine Control Module.

6. 6

   Reassembly

   Reconnect all harnesses and the battery cables. Clear the fault codes and run the engine to verify that the misfire/rough running condition is resolved and the code does not return.