# How to Fix Whirlpool Error F51 (Motor RPS Failure)
If your Whirlpool washing machine displays the F51 error code, it indicates a critical problem with the motor’s ability to operate at the correct speed. This guide will walk you through diagnosing and fixing the issue, which almost always centers on a specific electronic component known as the Rotor Position Sensor (RPS).
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## What Does Error F51 Mean?
**F51 = Motor RPS Failure (Rotor Position Sensor Failure)**
In plain English, the F51 code means the main control board (CCU) is not receiving accurate or consistent speed and position data from the drive motor. The Rotor Position Sensor (RPS) acts as a speedometer for the washer motor, telling the control board exactly how fast the drum is spinning and where the rotor is positioned.
When the RPS fails or the wiring leading to it is compromised, the control board loses “sight” of the motor. This prevents the machine from starting cycles, spinning, or balancing loads correctly, leading to an immediate shutdown and the display of F51.
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## Step-by-Step Fix: Diagnosing and Replacing the RPS
**Safety First:** Always unplug the washing machine from the wall outlet before attempting any inspection or repair. Failure to do so can result in serious injury or death.
### Step 1: Perform a Hard Reset
Before opening the machine, try clearing the fault memory. Sometimes a temporary power fluctuation causes the code.
1. **Unplug** the washer for at least **5 minutes**.
2. Plug the machine back in.
3. Attempt to start a new cycle.
If the F51 code returns, proceed to the physical inspection.
### Step 2: Inspect the Wiring Harness
The RPS relies on a stable connection to the main control board. If the wires are loose, damaged, or chewed (common with rodent issues), the signal is lost.
1. **Access the Rear Panel:** Carefully unscrew and remove the rear panel of the washing machine to gain access to the motor assembly.
2. **Locate the Motor:** The main drive motor is usually centrally located near the base of the machine.
3. **Inspect the RPS Harness:** Locate the wiring harness that plugs directly into the motor assembly. It may be a smaller plug attached near the center of the motor housing.
4. **Check for Damage:** Look for corrosion, broken plastic clips, or any visible breaks in the wire insulation. Secure any loose connections.
### Step 3: Access the Rotor Position Sensor (RPS)
If the wiring harness appears intact, the RPS itself is the most likely culprit and must be physically inspected or replaced.
The RPS is a small circuit board component mounted directly to the stator (the stationary part of the motor) beneath the rotating rotor.
1. **Remove the Rotor:** The rotor (the large, round metal assembly with magnets) must be pulled off the shaft. Depending on your model, this may require removing a central bolt or nut holding the rotor in place.
* *Caution:* Rotors are heavy due to the internal magnets. Be careful when removing them.
2. **Locate the Stator:** Once the rotor is off, the stator (the non-moving part attached to the tub) is exposed.
3. **Identify the RPS:** The RPS is typically attached to the stator via a few screws or clips. It is the component where the wiring harness you checked in Step 2 terminates.
### Step 4: Replace the Rotor Position Sensor
A failing RPS cannot be repaired—it must be replaced.
1. **Disconnect the Sensor:** Unplug the wiring harness completely from the faulty sensor.
2. **Remove the Old Sensor:** Unscrew or unclip the old RPS from the stator housing.
3. **Install the New Sensor:** Align the new RPS and secure it with the screws or clips.
4. **Reconnect:** Plug the wiring harness firmly into the new sensor.
5. **Reassemble:** Carefully place the rotor back onto the shaft and secure it with the central bolt/nut. Reinstall the rear panel.
### Step 5: Test the Machine
Plug the machine back in and run a short diagnostic cycle (refer to your owner’s manual for entering the specific diagnostic mode) or start a simple drain/spin cycle. If the RPS was the issue, the F51 error should be cleared, and the motor should spin normally.
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Check the price for a replacement Rotor Position Sensor here: https://www.amazon.com/s?k=Whirlpool+Rotor+Position+Sensor&tag=trivian-20