Yale 190-2 – Engine ECU or VSM: Crank Loss (CAM Pulse without Crank Pulse)

The engine control system is receiving a rotational signal from the Camshaft Position Sensor, but the corresponding signal from the Crankshaft Position Sensor is missing, erratic, or asymmetric.

• Yale and Hyster Forklifts
• Yale and Hyster forklifts (2005 and newer)
• GC135VX
• ERP040VT
• GP040-060MX

1. 1

   Inspect the crankshaft sensor housing and encoder wheel for dust, debris, or metal shavings

2. 2

   Verify that the engine timing belt is tensioned properly (a loose belt can cause synchronization loss)

3. 3

   Check the sensor supply and ground circuits for open connections

4. 4

   Check the sensor signal wires for an open circuit, a short to ground, or a short to the battery source

5. 5

   Inspect the sensor mounting bracket and the encoder wheel for physical damage

1. 1

   Power Down

   Disconnect the forklift battery to ensure safety and prevent electrical shorts during testing.

2. 2

   Clean the Sensor

   Locate the crankshaft position sensor on the engine block. Remove it and clean the sensor tip and housing of any accumulated dust or debris. Reinstall and test; if the code persists, proceed to the next step.

3. 3

   Verify Timing Belt

   Inspect the timing belt. If it is loose or damaged, adjust the tension to factory specifications or replace the belt.

4. 4

   Test the Harness

   Using a multimeter, trace the wiring harness from the crank sensor connector back to the Engine ECU. Test for continuity, open circuits, and shorts. Repair or replace the wiring harness if any faults are found.

5. 5

   Replace the Sensor

   If the wiring and timing belt are good, the crankshaft position sensor has likely failed internally. Replace it with a new OEM sensor.

6. 6

   Controller Replacement (Worst Case)

   If a new sensor and verified wiring do not clear the code, the Engine ECU/Controller has suffered a functional failure and must be replaced or reprogrammed by an authorized dealer.

7. 7

   Clear Codes

   Reconnect the battery, clear the fault codes via the dash display or diagnostic software, and test-run the engine to ensure the code does not return.