Common Causes of Reduced Forklift Speed and Power

Have you noticed that your forklift is running slower than usual?
・Is your forklift losing power?
・Is acceleration weaker than before?
・Does it struggle when going uphill?
・Has the top speed suddenly decreased?

A slow forklift is one of the most common issues in warehouses and industrial sites.
However, reduced speed does not always mean a major failure. In many cases, the machine is intentionally limiting performance for safety reasons.
In this article, we explain the most common reasons why your forklift may be running slow.

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1️⃣Overheating (Temperature Protection Mode)

One of the most common causes is overheating.

Examples include:

• Drive motor overheating
• Pump motor overheating
• Controller board temperature rise

When excessive temperature is detected, the system automatically activates protection mode. This may result in:

• Reduced maximum speed
• Slow acceleration
• Limited hydraulic performance
• Complete travel stop in severe cases

Check whether the O/H (Overheat) indicator is illuminated on the display.

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2️⃣ Battery Voltage or Charging Issues

For electric forklifts, battery condition directly affects performance.

Common issues include:

• Low battery charge
• Battery voltage abnormalities
• Battery current sensor errors
• On-board charger errors

When voltage drops, the system reduces output power to protect components.
This often makes the forklift feel weak or slow.

Always check battery level and any related error codes first.

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3️⃣Sensor Abnormalities

Modern forklifts rely on multiple safety sensors.

For example:

• Accelerator potentiometer errors
• Brake potentiometer errors
• Tilt angle sensor errors
• Load sensor errors

If these sensors detect abnormal signals, the system may limit speed for safety.

Look for a flashing wrench icon or displayed error code.

You can check our full error code list here:
👉 ERROR CODE LIST

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4️⃣ Safety Control Activation

In some cases, the forklift is not “broken” — it is protecting itself.

Examples:

• Incline detection limiting output
• Load sensing reducing speed
• Travel restrictions when lifting

These systems prevent accidents and mechanical damage.

If your forklift slows down while lifting high loads or operating on slopes, this may be normal safety behavior.

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5️⃣ Brake Drag or Mechanical Resistance

Physical resistance can also cause reduced speed.

Possible causes:

• Brake drag
• Drive motor abnormalities
• Drive motor driver issues
• Transmission resistance

In these cases, the forklift may feel heavy, even if no warning lamp is active.

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6️⃣ Speed Setting or Operator Mode

Sometimes the issue is simply configuration.

Check if:

• Maximum speed setting was reduced
• Eco mode is enabled
• Operator speed restriction is active

Many fleets limit speed intentionally for safety compliance.

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What Should You Check First?

Before assuming a major failure, confirm the following:

✔ Is the O/H lamp on?
✔ Is the wrench icon flashing?
✔ Is an error code displayed?
✔ Is the battery sufficiently charged?

If an error code appears, refer to the detailed explanation pages on our website.

👉 ERROR CODE LIST