E09 Bosch Washer Error Code Troubleshooting Guide

Bosch front-loading washing machines are designed to be efficient, effective, and reliable. However, like any appliance, they can develop issues. One error code that appears is the E09 Bosch washer error code. This signifies a communication failure between the control module and motor control module in the washer. When this code pops up, the washer may not run properly or at all. 

Troubleshooting and resolving an E09 error code isn’t too difficult with the right knowledge. In this comprehensive guide, we’ll walk through all the steps needed to diagnose the issue and get your Bosch front-loader running again.

Understanding the E09 Error Code

On Bosch front-loading washers, the E09 code indicates a loss of communication between the electronic control module and the motor control module. These two components need to “talk” to each other for the washer to operate correctly.

The control module is the computer brain of the washer. It handles all the logic, inputs, sensors, and user controls. The motor control module specifically provides power to the motor and allows it to run at different speeds. For the washer to fill, agitate, drain and spin, these two modules must communicate.

When the E09 code pops up, it means the connection between the control and motor control modules has been interrupted. This could occur due to a wiring problem or an issue with one of the modules. Without communication, the motor and other components won’t activate properly.

Step 1 – Check Wire Harness Connections

The first step in troubleshooting an E09 error is verifying the wiring between the two modules. Start by ensuring the wire harness is properly connected at both ends. The connectors should be fully inserted and locked into their receptacles on each module.

Visually inspect the length of the wire harness as well. Look for any cuts, crimps, or damage that could be interrupting the communication. Wiggling the wires may reveal a broken spot.

If the harness connections are good, the next step is checking voltage delivery. But if the harness itself seems faulty, go ahead and replace it right away. That will likely resolve the E09 code.

Step 2 – Test Voltage to the Motor

With the washer powered on and set to run a wash cycle, use a multimeter to check the voltage being delivered from the motor control module to the motor. You’ll need to back-probe the connectors to take accurate readings.

On Bosch front-load washers, the expected voltage range is around 120 VAC at a frequency between 0-400Hz. This three-phase power allows the motor to operate at different speeds.

If your voltage readings are very low or nonexistent, it points to a problem with the motor control module itself. It’s not properly sending power to the motor windings. In that case, the module will need to be replaced to restore normal operation.

Low or no voltage means the wiring is okay, but the component responsible for powering the motor is likely faulty.

Step 3 – Verify Motor Resistance

Assuming you find proper voltage of 120VAC reaching the motor, the next step is checking the motor windings themselves.

To do this, disconnect power to the washer. Use a multimeter to measure the resistance between the motor windings. Resistance values should fall between 5 to 15 ohms in most cases.

If the windings have very high resistance, low continuity, or no continuity at all, it indicates a problem with the motor itself. The motor will need to be replaced if the windings are damaged or worn out.

This step helps determine if the issue lies with the motor or one of the electrical components. If the motor windings seem fine, move on to inspecting the modules.

Step 4 – Replace Control Module

If the wire harness is intact and motor voltage and resistance check out okay, the control module itself may be the culprit.

To confirm, replace the control module with a new one and see if that restores normal operation. These modules can fail internally and cause erratic operation and error codes.

When installing a replacement control module, take care to properly reconnect all the wire harness connectors. Also, don’t forget to reload any custom program settings that were being used.

Many times, replacing a faulty control module will resolve an E09 communication error. The module handles the “talking” between components.

Step 5 – Replace Motor Control Module

The last component to address with an E09 code is the motor control module.

If motor voltage readings were way off during testing in step 2, the motor control module likely needs to be replaced. Even if the motor windings seem fine, a damaged module could be preventing the proper voltage from reaching the motor.

Swap in a new motor control module and see if normal washer operation is restored. When installing the replacement, carefully reconnect all the wire harnesses and connectors. Also, make sure the module is securely mounted.

Along with the control module, a bad motor control module is a prime suspect with an E09 error code.

Retesting after Repairs

After replacing any parts related to an E09 code, thoroughly retest the washer. Run it through a full wash cycle and make sure it operates normally without any error codes appearing.

The washer should fill, wash, drain and spin properly while reaching the expected speeds and temperatures. Monitor voltage during the test cycle to see if readings are in the proper 120VAC range.

If the E09 or any other code pops up again, you may need to retry the troubleshooting steps and replace a different component. With the power disconnected, also double check for any loose wire harness connections.

With the right replacement part, the E09 communication error should be resolved and the Bosch front-loader returned to reliable operation. And remember if you need a visual aid to help you replace the parts, make sure to check out our YouTube.

Preventing Future E09 Codes

Like other appliances, washing machines can develop intermittent glitches. Following good maintenance practices can minimize issues down the road.

Here are some tips to keep your Bosch washer running smoothly:

• Use a surge protector to avoid control board damage from power spikes
• Avoid overloading the washer to prevent strain on components
• Clean the washer monthly to remove soap buildup and debris
• Use proper detergent and water levels to prevent oversudsing
• Leave the door open after cycles to dry out the drum
• Tighten any loose electrical connections to avoid future wiring faults

While not every problem can be prevented, proper care and maintenance will lead to more years of reliable service from your Bosch front-loading washer. Be sure to follow good usage and cleaning practices.

Conclusion

When a Bosch washer won’t run and shows an E09 code, don’t panic. In most cases, the issue can be resolved with some targeted troubleshooting. Just take organized steps to diagnose the problem. Check wire harness connections, motor voltage, motor windings, and try replacing the control board and motor control module one at a time. With the right replacement part, you’ll have the washer running smoothly again. Remember when replacing parts, it is always a good idea to replace them with OEM replacement parts which you can find by clicking here.

Be sure to thoroughly test the washer after any repairs. Also make sure to follow the maintenance tips above to maximize the lifespan of your Bosch front-loading washing machine. With the proper care, your washer should provide many years of dependable service.