VERIFIED
E03 is a Bosch dishwasher electronics code linked to a main-board relay fault. Confirm the model and avoid treating the code as proof of one failed part.
Bosch dishwasher code E03 directs attention to main control-board relay fault. The most useful first step is to preserve the exact display and model information, because similar-looking Bosch machines can use different hardware and control logic.
What the dishwasher is reporting
The technical anchor for this record is main control-board relay fault. Keep that meaning tied to the exact dishwasher platform. The code identifies a condition detected by the control system, while the full model number and the behavior immediately before the warning help determine the actual repair path.
Useful symptoms to record
- a wash program can end early
- the dishwasher may not begin the next stage of a cycle
- the warning may return shortly after power is restored
- controls can appear normal until the relay is commanded again
Possible fault paths
- a relay or switching fault on the main control
- an electrical path connected to that relay that is outside expected conditions
- wiring or connection problems that require model-specific testing
Safe first observations
- Write down the exact E03 code and E-Nr.
- If the machine is otherwise electrically safe and the documentation allows it, perform one normal power cycle.
- Do not probe the main control, relays, or internal harnesses.
When to stop
Do not continue using the dishwasher if E03 is accompanied by burning odor, smoke, sparking, or recurring breaker trips.
Why the next step may be service
When E03 returns, the useful question is not “which board should I order?” but which part of the relay-controlled circuit is creating the fault. That requires the exact model and electrical testing inside the service boundary.
Model note
Use the complete Bosch E-Nr/model number from the rating label. Do not assume that another Bosch dishwasher with the same exterior design uses the same internal components or diagnostic sequence.
FAQ
Both may be associated with main control-board relay faults on supported Bosch dishwasher platforms, but the exact model and source record should still be matched before diagnosis.
The verified E03 meaning is a relay fault, not a door-sensor code. Door closure can affect operation generally, but it should not replace the code-specific diagnostic path.
Only if the model documentation permits it and there are no electrical warning signs. If E03 returns, stop resetting and diagnose the cause.
Record whether E03 returns immediately, at the same cycle stage, or only when a particular function starts.
When to request Bosch dishwasher service
Still seeing E03 on your Bosch dishwasher?
If the warning remains active or comes back after the appropriate safe checks, request Bosch dishwasher diagnosis in the San Francisco Bay Area. Include the full E-Nr, the exact code, what the dishwasher was doing when it appeared, and your service ZIP code.
Technical source: https://www.bosch-home.com/us/owner-support/error-codes/dishwashers
Model compatibility: Bosch reuses codes across series and model years, so E03 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.