# How to Fix Bosch Error E10 (Motor Fault)
Bosch Error Code E10 is a critical fault indicating that the washing machine’s main drive motor is experiencing a failure or the machine’s control board cannot correctly read the motor’s operation.
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## What Bosch Error E10 Means
The E10 error code is generated when the main control unit (PCB) detects an issue with the operation of the primary **Motor Assembly**. This typically falls into one of three categories:
1. **Motor Failure:** The windings are faulty, the carbon brushes (in older models) are worn, or the motor has seized.
2. **Tachometer Sensor Failure:** The sensor (Tacho) that reports the motor speed back to the control board is defective or disconnected, leading the machine to believe the motor is not running.
3. **Wiring Issue:** The wiring harness between the motor and the main PCB is loose, damaged, or has a short circuit.
Since the motor is essential for spinning and agitation, the machine will usually stop mid-cycle and lock the door when this error appears.
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## Step-by-Step Troubleshooting Guide
** Safety First:** Always unplug the washing machine from the wall power outlet before attempting any inspection or repair inside the unit.
### Step 1: Perform a Hard Reset and Check for Obstructions
Before diving into electrical testing, ensure the error is not temporary and that the drum is free to move.
1. **Unplug:** Disconnect the machine for 5 minutes.
2. **Plug In and Reset:** Plug the machine back in and attempt to clear the error using the ‘Off’ position or by holding the Start/Pause button for 5 seconds (refer to your specific Bosch manual for the reset process).
3. **Check the Drum:** Open the door (if possible) and try to spin the drum by hand. It should move freely. If it is jammed, check the drain pump and filter for large items (e.g., coins, underwire) that may have locked the drum rotation.
### Step 2: Access the Motor and Check the Wiring Harness
The motor is typically accessed from the rear of the machine by removing the large back panel.
1. **Remove Panel:** Unscrew and remove the machine’s rear access panel.
2. **Locate Motor:** The motor is usually found beneath the drum, attached to the drum shaft via a belt (or directly attached in modern direct-drive models).
3. **Inspect Connections:** Carefully trace the wiring harness leading from the control board down to the motor.
* Check that the electrical connector plugs are seated firmly into the motor housing.
* Look for visible signs of damage, chafing, melted plastic, or burn marks on the wires or connector plugs.
### Step 3: Inspect Carbon Brushes (Brushed Motors Only)
If your Bosch model uses a brushed motor (older models often do), worn brushes are the single most common cause of motor failure.
1. **Remove Brushes:** The brushes are held in small plastic housings on either side of the motor. You may need to partially remove the motor to access them.
2. **Check Length:** Remove the brushes and measure the remaining length of the carbon block. If the carbon block is less than **0.5 inches (12-15mm)** long, they must be replaced.
3. **Note:** If your model has a brushless (inverter) motor, skip this step, as they do not have carbon brushes.
### Step 4: Test the Tachometer Sensor (The Speed Sensor)
The tachometer sensor (or Hall sensor) reports the speed of the motor back to the control board. If this sensor fails, the control board receives no speed feedback, triggers the E10 fault, and shuts down the cycle.
1. **Locate:** The tacho sensor is usually a small component located at the back of the motor, often integrated into the pulley wheel or rear casing. It will have its own small wiring connector.
2. **Check Resistance:** Disconnect the tacho sensor connector and use a multimeter set to Ohms (Ω). Test the resistance across the two terminals.
* A healthy tachometer reading should typically fall between **60 and 150 Ohms** (check your specific motor specifications if possible).
* A reading of 0 or an “open loop” (OL/infinite resistance) indicates a faulty sensor which requires the motor assembly (or just the sensor, if replaceable) to be replaced.
### Step 5: Test the Motor Windings (Final Confirmation)
If all wiring is secure and the carbon brushes are fine (or the motor is brushless), you must test the motor windings for internal faults.
1. **Identify Terminals:** Disconnect the main motor connector plug. Use a wiring diagram or identify the terminals corresponding to the main motor windings (not the tacho sensor).
2. **Measure Resistance:** Using a multimeter, measure the resistance across the motor winding terminals.
* **Healthy Motor:** You should see a very low, but measurable, resistance (usually under 10 Ohms). The readings between the winding pairs should be consistent.
* **Faulty Motor:** If you receive an open reading (OL/infinite resistance) across the terminals, the motor windings have failed.
3. **Check for Ground Fault:** Check resistance between any motor winding terminal and the bare metal frame of the motor. A reading of 0 (continuity) indicates the motor has shorted to ground and must be replaced.
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### Call to Action
If the motor brushes are adequate, the wiring is secure, and the tachometer or winding tests indicate failure, the Motor Assembly needs replacement.
Check the price for a replacement Motor Assembly here: https://www.amazon.com/s?k=Bosch+Motor Assembly&tag=trivian-20