yale glp050vx toss sensor

by

The Yale GLP050VX forklift truck is a widely used model known for its rugged durability, efficiency, and dependable performance in material handling operations. Among its many integrated technologies, the TOSS sensor (Transmission Output Speed Sensor) plays a crucial role in ensuring optimal vehicle performance and safety. This article provides a detailed, technical, and user-friendly explanation of the Yale GLP050VX TOSS sensor, including its function, importance, working principles, common issues, diagnostics, and maintenance tips.

Introduction to Yale GLP050VX Forklift

Before we dive into the TOSS sensor, it’s important to understand the basic structure of the Yale GLP050VX forklift.

  • Model Type: GLP050VX
  • Capacity: 5,000 lbs
  • Fuel Type: LPG (Liquid Propane Gas)
  • Drive System: Internal combustion with automatic transmission
  • Applications: Warehousing, manufacturing, logistics, outdoor yard work

The GLP050VX is part of Yale’s Veracitor® VX series, a line of trucks engineered for productivity, ergonomics, and cost-effective operation.

One of the key systems in this forklift model is the transmission system, which includes various sensors for monitoring and control. One such sensor is the Transmission Output Speed Sensor, commonly referred to as the TOSS sensor.

What is the TOSS Sensor?

TOSS stands for Transmission Output Speed Sensor. In the Yale GLP050VX, this sensor monitors the rotational speed of the transmission output shaft. The data collected is crucial for:

  • Controlling gear shifts
  • Maintaining optimal transmission pressure
  • Synchronizing engine and transmission speeds
  • Enhancing fuel efficiency
  • Preventing drivetrain damage

The TOSS sensor essentially acts as a feedback device that communicates with the Electronic Control Module (ECM) to regulate transmission behavior.

Function of the TOSS Sensor in Yale GLP050VX

In the Yale GLP050VX forklift, the TOSS sensor serves several key functions:

1. Transmission Control

It helps the ECM determine the actual speed of the output shaft, which is essential for automatic gear shifting. Without this data, the system would be blind to the actual load and movement of the vehicle.

2. Engine Synchronization

By comparing the input speed (via another sensor) and output speed (TOSS), the control system can decide whether the engine and transmission are in sync. This prevents jerky movement and gear grinding.

3. Safety Interlocks

If the TOSS sensor detects erratic speed signals or abnormal values, it can trigger fail-safe modes, warning lights, or limit engine power to protect the transmission.

4. Diagnostics

The TOSS sensor is also a diagnostic tool. Fault codes related to the TOSS sensor (such as SPN 8492, FMI 2) help technicians pinpoint problems in the transmission system.

How Does the TOSS Sensor Work?

The Yale GLP050VX TOSS sensor is typically a magnetic or Hall-effect sensor mounted on the transmission housing. Here’s a breakdown of its working:

  • A toothed reluctor ring is attached to the output shaft.
  • As the shaft rotates, the teeth pass by the magnetic sensor.
  • Each tooth generates a pulse—the faster the shaft turns, the higher the frequency of these pulses.
  • These pulses are sent as a digital signal to the ECM.
  • The ECM interprets the frequency as rotational speed (RPM).

In advanced systems, TOSS sensors can detect speed changes with great precision and are immune to dust, oil, and temperature fluctuations.

Symptoms of a Faulty TOSS Sensor

A malfunctioning TOSS sensor can significantly affect the performance and safety of the Yale GLP050VX forklift. Common signs include:

  1. Erratic Shifting: The transmission may shift unpredictably or not at all.
  2. Transmission Stuck in Gear: Failure to detect speed may cause it to remain in a single gear.
  3. Loss of Power: The ECM may reduce engine output as a safety measure.
  4. Check Engine Light: A diagnostic fault code will often appear.
  5. Rough Operation: You may experience jerky starts or stops.
  6. No Movement: In severe cases, the forklift may not move despite engine acceleration.

Diagnostic Trouble Codes (DTCs) for TOSS Sensor

When the TOSS sensor in the Yale GLP050VX fails, it often triggers specific DTCs (Diagnostic Trouble Codes). Common examples include:

  • SPN 8492 FMI 2: Indicates the TOSS signal is missing or out of range.
  • SPN 8492 FMI 7: Suggests an internal failure or open circuit.
  • SPN 8492 FMI 9: Typically means intermittent signal or low voltage.

To check these codes, a diagnostic tool or handheld scanner compatible with Yale’s system is required.

How to Test the TOSS Sensor

Testing the Yale GLP050VX TOSS sensor involves a few basic steps. You’ll need:

  • A digital multimeter (DMM)
  • The service manual or wiring diagram
  • Access to the ECM or sensor harness

Step-by-Step Guide:

  1. Visual Inspection:
    • Check for physical damage, corrosion, or disconnection.
    • Inspect wiring for burns, cracks, or loose connectors.
  2. Resistance Test:
    • Disconnect the sensor.
    • Measure resistance across the sensor terminals.
    • Typical values range between 500 to 1500 ohms (consult the manual).
  3. Signal Output Test:
    • Reconnect sensor and back-probe the signal wire.
    • Spin the output shaft manually.
    • You should see fluctuating voltage (0.5V to 5V) if it’s a Hall-effect sensor.
  4. Check Continuity:
    • Verify there is no short to ground or power in the harness.

If the sensor passes all these tests but the forklift still shows errors, the problem could be the ECM, not the sensor.

Replacing the TOSS Sensor

If the sensor is confirmed to be faulty, follow these steps to replace it:

  1. Turn off the forklift and disconnect the battery.
  2. Locate the TOSS sensor—usually mounted near the rear of the transmission.
  3. Unplug the connector.
  4. Remove the mounting bolt using a socket wrench.
  5. Extract the old sensor carefully to avoid damaging the housing.
  6. Clean the mounting area.
  7. Insert the new sensor, ensuring proper alignment.
  8. Reinstall the bolt and torque it to specification.
  9. Reconnect the wire and battery.
  10. Clear any stored DTCs using the diagnostic tool.

Maintenance Tips for TOSS Sensor Longevity

  1. Keep Transmission Clean: Oil leaks can foul the sensor over time.
  2. Regular Inspections: Inspect connectors during routine maintenance.
  3. Avoid High Pressure Water Near Transmission: Water ingress can short the sensor.
  4. Use Genuine Parts: Always replace with OEM or certified compatible sensors.
  5. Monitor Forklift Behavior: Early diagnosis can prevent serious issues.

OEM Part Numbers and Compatible Sensors

Yale does not always publish standalone part numbers for internal sensors, but some commonly referenced OEM part numbers compatible with Yale GLP050VX TOSS sensor include:

  • 580063808 (varies by manufacturing year)
  • GM 24237276 (in some cross-reference charts)
  • TCM or Hyster equivalents may also match

Make sure to cross-verify with the serial number of your forklift before ordering.

Integration with Other Systems

The TOSS sensor in the GLP050VX does not work alone. It is part of an integrated system involving:

  • Engine Control Module (ECM)
  • Transmission Control Module (TCM)
  • Vehicle Speed Sensor (VSS)
  • Throttle Position Sensor (TPS)
  • Load Sensor

All these components must work in harmony for smooth performance. A fault in one may lead to misleading TOSS sensor error codes.

Troubleshooting Without a Diagnostic Tool

In case you don’t have access to a scanner, use these old-school techniques:

  • Manual spin test: Lift the rear wheels and turn the driveshaft by hand while checking sensor output.
  • Swap Test: If you have a fleet, try swapping sensors between machines (if compatible).
  • Wiggle Test: Gently wiggle the sensor wiring while the forklift is on to check for intermittent issues.

Conclusion

The yale glp050vx toss sensor is a vital component of the transmission and performance monitoring system of the forklift. Without it, key functionalities like automatic shifting, engine synchronization, and safety controls would fail. Understanding how it works, recognizing failure symptoms, and learning how to test and replace it can significantly reduce forklift downtime and prevent expensive repairs.

Whether you’re a technician, fleet manager, or forklift operator, maintaining a healthy TOSS sensor is essential for smooth, safe, and efficient forklift operations.

Leave a Comment