Error code reference

Bosch Dishwasher Error Code E6

Aqua sensor error

Bosch codesBosch dishwasher codes

Aqua sensor error – the water cleanliness sensor has failed or is not communicating properly.

First step from the service manual

Check the aqua sensor assembly located behind the sump to the left of the heater.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E6 means on a Bosch dishwasher

The E6 error on a Bosch dishwasher indicates a fault with the aqua sensor, also called the turbidity sensor. The control board monitors signals from this sensor throughout the wash cycle and throws E6 when it receives a reading that falls outside the expected range, receives no signal at all, or detects an implausible value that does not match operating conditions. The aqua sensor is typically mounted on the sump assembly near the circulation pump inlet.

The aqua sensor measures how dirty or cloudy the wash water is. Bosch uses this data to automatically adjust cycle length and water consumption based on actual soil load rather than running a fixed program every time. When the sensor fails or loses communication with the control board, the machine cannot make these adjustments and stops the cycle to flag the problem.

The sensor itself can fail due to contamination from grease or mineral deposits, physical damage, or internal electronic failure. The wiring harness connecting it to the control board is also a common weak point, especially the connector at the sensor end, which is exposed to heat and moisture over time.

Source: manufacturer service documentation.

Common causes of E6

  1. 01

    Contaminated or fouled aqua sensor

    Wiring / connection

    Grease, limescale, or detergent residue can coat the sensor's optical lens, causing it to send inaccurate or no readings to the control board. This is the most common cause and often appears after years of use or in hard water areas.

  2. 02

    Failed aqua sensor

    Part replacement

    The sensor's internal optical or electronic components can fail outright, producing a signal the control board flags as implausible. Cleaning will not restore function when the sensor has failed internally.

  3. 03

    Damaged or disconnected wiring harness to the aqua sensor

    Part replacement

    The connector or wiring between the aqua sensor and the control board can corrode, crack, or work loose due to heat cycling and vibration. A broken wire or poor connection produces the same missing or out-of-range signal as a dead sensor.

  4. 04

    Faulty control board

    Part replacement

    If the aqua sensor and its wiring test within specification but the E6 error persists, the control board's sensor input circuit may have failed. This is the least likely cause and should only be considered after ruling out the sensor and wiring.

See the test procedure for each cause

Frequently asked questions about E6

What does the E6 error code mean on a Bosch dishwasher?
E6 on a Bosch dishwasher means the control board has detected a problem with the aqua sensor, also called the turbidity sensor. This sensor monitors water clarity during the wash cycle so the machine can adjust water usage and cycle time automatically. When the board receives a signal that is missing or outside the expected range, it stops the cycle and displays E6.
How do I fix the E6 error on my Bosch dishwasher?
Start by locating the aqua sensor on the sump assembly and cleaning it. Grease and limescale buildup on the sensor's optical lens is the most frequent cause of E6. Remove the sensor, clean the lens carefully with a soft cloth and a mild descaling solution, reinstall it, and run a test cycle. If the error returns, check the wiring harness connector at the sensor for corrosion or looseness before replacing the sensor itself.
Can I still use my Bosch dishwasher when it shows E6?
Running the dishwasher with an active E6 error is not recommended. The machine has halted the cycle because it cannot verify water conditions, so dishes will not be properly cleaned and the cycle will not complete normally. Continued attempts to run cycles without resolving the fault can also stress other components. Address the aqua sensor issue before resuming regular use.
How much does it cost to fix a Bosch dishwasher E6 error?
If the sensor only needs cleaning, the repair costs nothing beyond your time. A replacement aqua sensor for a Bosch dishwasher typically costs between $20 and $60 for the part. If a technician is needed to diagnose and replace it, expect a total repair bill in the range of $100 to $200 depending on your location and labor rates. A control board replacement, which is rarely the actual fix, would cost significantly more.
Is the E6 error on a Bosch dishwasher something I can fix myself?
Cleaning the aqua sensor is well within DIY reach for most homeowners. The sump area is accessible after removing the lower spray arm and filter assembly. Replacing the sensor itself is also a manageable DIY repair since it is a plug-in component on most Bosch models. If the wiring harness is damaged or the error points to the control board, a repair technician is a practical choice to avoid misdiagnosis.

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