Yale 190-2 – Engine ECU or VSM: Engine RPM Sensor Output Is Less Than Engine Speed

The controller is receiving an erratic, missing, or abnormally low rotational speed signal from the engine RPM sensor (crankshaft position sensor) compared to what the engine is actually doing.

• Yale and Hyster Forklifts
• VX series
• FT series
• GDP20VX
• GDP35VX
• GLC030VX
• GC040VX
• GLP060VX

1. 1

   Check the power supply wire to the sensor for an open circuit, breaks, or loose connections

2. 2

   Test the signal wire between the sensor and the ECU for continuity and ensure it is not shorted to ground

3. 3

   Verify the sensor signal wire is not shorted to a battery voltage source

4. 4

   Test the engine RPM sensor itself for internal failure

5. 5

   If all wiring and the sensor test good, check for a functional failure in the ECU or VSM

1. 1

   Visual Inspection

   Locate the Engine RPM Sensor (Crankshaft Position Sensor) on the engine block/timing cover. Inspect the sensor housing for dust, debris, or physical damage.

2. 2

   Harness Check

   Disconnect the sensor and inspect the connector pins for corrosion or pushed-back terminals.

3. 3

   Circuit Testing

   Using a multimeter, verify that the sensor is receiving the correct supply voltage and has a solid ground.

4. 4

   Signal Testing

   Check the continuity of the signal wire from the sensor harness directly to the ECU pinout.

5. 5

   Sensor Replacement

   If the wiring harness passes all tests (no opens, no shorts to ground/power), the sensor has failed internally. Remove the mounting screw, extract the old sensor, and install the new one.

6. 6

   Verification

   Clear the fault codes from the dash/VSM and run the engine to verify that the RPM data is reading accurately and the code does not return.