Yale 522585-2 – Mazda Gas ECU: Engine RPM Sensor (Mazda Gas ECU)

Engine RPM Sensor output is less than the commanded/actual engine speed, or there is a loss of pulse from the sensor.

• Yale and Hyster Forklifts
• Yale VX
• Hyster FT

1. 1

   Inspect the wiring harness and connectors between the RPM sensor (crankshaft position sensor) and the Mazda ECU for damage, corrosion, or loose pins.

2. 2

   Check for an open circuit in the sensor power supply.

3. 3

   Check if the sensor signal wire is open or shorted to ground.

4. 4

   Check if the sensor signal wire is shorted to a battery source.

5. 5

   Disconnect the sensor and measure the resistance across its terminals to see if it is out of specification (open or shorted internally).

6. 6

   Check for a pulse signal while cranking the engine.

7. 7

   If the sensor and wiring both test good, verify if there is a functional failure within the controller (ECU) itself.

1. 1

   Power Down

   Turn off the forklift ignition, engage the parking brake, and disconnect the negative battery terminal.

2. 2

   Locate the Sensor

   Locate the Engine RPM sensor. On the Mazda FE/F2 engines, this sensor is typically mounted on the flywheel housing where it reads the flywheel gear teeth.

3. 3

   Remove the Sensor

   Disconnect the electrical connector from the sensor. Remove the retaining bolt(s) holding the sensor to the housing and carefully pull the sensor out.

4. 4

   Install the New Sensor

   Insert the replacement RPM sensor into the housing. Secure it with the retaining bolt and torque to the manufacturer's specification.

5. 5

   Reconnect

   Plug the electrical connector back into the sensor, ensuring it clicks securely into place.

6. 6

   Test

   Reconnect the battery. Turn the key to the ON position and clear the stored fault codes using the dash display or a handset tool. Start the engine and verify that it runs smoothly without triggering the 522585-2 code.