E37
Bosch Dishwasher
Severity: ModerateWhat Does This Error Mean?
The E37 error on a Bosch dishwasher indicates a turbidity sensor fault. The turbidity sensor measures how dirty the wash water is and helps the dishwasher decide how long and how intensely to wash. When this sensor fails or gets too dirty, the dishwasher cannot complete its automatic wash program.
Affected Models
- SHPM88Z75N
- SHPM65Z55N
- SHEM63W55N
- SHDX5EM3N
- Most Bosch 500, 800 series dishwashers
Common Causes
- Turbidity sensor is coated with limescale, grease, or food residue
- Turbidity sensor has developed an electrical fault and needs replacement
- Wiring harness to the turbidity sensor is loose or damaged
- Control board is not receiving a valid signal from the sensor
- Hard water deposits have built up on the sensor lens
How to Fix It
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Run an empty dishwasher cycle with a dishwasher cleaning tablet or citric acid powder.
Descaling the inside of the dishwasher often cleans the turbidity sensor at the same time. This is the easiest first step.
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Remove and clean the drain filter thoroughly.
A heavily soiled filter causes dirty water to circulate back over the sensor, coating it with residue. Clean the filter and the area around it.
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Locate the turbidity sensor — it is typically at the bottom of the tub near the sump.
It looks like a small disc or probe with a wiring connector. Carefully clean its surface with a soft damp cloth.
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Reset the dishwasher by turning the power off at the circuit breaker for 5 minutes.
A full power reset after cleaning the sensor gives the control board a fresh start.
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Run a test cycle and observe. If E37 returns, the sensor needs professional replacement.
Turbidity sensors can fail electronically after years of use. A technician can confirm with a resistance test and replace it.
When to Call a Professional
If cleaning the sensor does not clear E37, it may need replacement. Accessing the turbidity sensor requires removing the dishwasher from the cabinet and some disassembly. Expect repair costs of $100–$200.
Frequently Asked Questions
What is a turbidity sensor in a Bosch dishwasher?
The turbidity sensor uses light to measure how cloudy the wash water is. At the start of a cycle, wash water is clear. As it picks up food and grease, it becomes cloudy. The sensor reads this cloudiness and tells the control board how dirty the water is, adjusting the wash accordingly.
Does hard water affect the turbidity sensor?
Yes — hard water leaves limescale deposits on the sensor lens over time. This can make the sensor give inaccurate readings or fail entirely. Using dishwasher salt and a regular descaling cycle helps prevent buildup. Bosch dishwashers have a built-in water softener that requires salt to function.
Can I run my Bosch dishwasher without a working turbidity sensor?
The dishwasher needs the sensor to complete automatic programs. Without it, the machine cannot determine wash intensity and will either stop mid-cycle or show E37. You may be able to use a manual timed program on some models as a temporary workaround.