The short answer
A SMU dishwasher that will not start is usually not being asked to start: a control lock, a delay-start setting or a door that is not quite latched account for most of these calls before any part is suspected. The seven codes in the table share the family stem and sit close together in build, so the layout described here holds across them.
What you observe on these models
- The panel is completely dark and nothing responds — No power reaching the machine: breaker, the outlet under the sink, or the junction box connection behind the toe-kick.
- The panel lights but the cycle never begins — Power is fine. This is a door latch, a control lock, a delay start, or a control that is waiting on something it cannot get.
- A lock or key symbol is showing — The control lock is engaged. It is a deliberate feature, usually set by a long press, and it makes the machine look dead while everything works.
- NEAR MISS — the cycle starts and then aborts part way with water in the tub — That is a drain fault, not a start fault. The drainage page for this family covers it.
Causes, most likely first on the SMU family
- The control lock or a delay start is set — First on a new installation, where the lock and delay features are least familiar.
- The door is not latching, or the latch switch is not making — Second. Push the door firmly at the handle and listen for a positive click.
- No power is reaching the machine — Ranked here because a dark panel has exactly one meaning, and because on a recent installation an unseated plug or an unswitched outlet is more likely than a failed part.
- The machine is waiting for water it is not getting — Ranked above the electronics because it is the classic post-installation fault: the supply valve under the sink was never fully opened.
- The control board has failed — Last, and by elimination only. On units this young a board failure is unusual, and diagnosing it means measuring, not guessing.
Check in this order, and why
- Press start and watch the panel, not the machine — Dark panel, lit panel with no cycle, or a cycle that begins and stalls — those three outcomes split this list into three branches, and you get the answer in one press.
- Clear any lock and any delay — Hold the marked lock button for several seconds, and cancel a delay start if one is counting.
- Close the door hard and listen for the latch — A positive click is what the control is waiting for. Check that no rack, no baking sheet and no oversized plate is holding the door a fraction open at the top.
- Check the breaker and the outlet — Reset the breaker once, and test the outlet under the sink if the machine is plugged rather than hard-wired.
- Open the supply valve fully — If the cycle starts and then waits with a dry tub, the water is the fault.
Models in the SMU family — Each code here is pinned to a single build, so match the tag inside your door frame character for character. The seven codes fall into four leading groups, and that spread is the reason this page is written for the family rather than for one machine.
Reference| Model number | Family key |
|---|---|
| SMU2ITS01A | bosch:dishwasher:smu |
| SMU4HTS01A | bosch:dishwasher:smu |
| SMU4HVS01A | bosch:dishwasher:smu |
| SMU6HAS01A | bosch:dishwasher:smu |
| SMU6HCS01A | bosch:dishwasher:smu |
| SMU6HCS02A | bosch:dishwasher:smu |
| SMU8ECS01A | bosch:dishwasher:smu |
Before you open anything
Safety
The owner checks here are done with the machine closed and powered. Beyond them — the junction box behind the toe-kick, the latch assembly, the panel — switch the breaker off first; a capacitor can hold a charge after the power is off.
When to call a technician
Settings, the door, the breaker and the supply valve are owner checks on these models. Call when the machine has power and still refuses, when only some buttons respond, or when the breaker trips every time a cycle is selected — that last one is a fault being reported, and resetting it repeatedly is unsafe.
Sources — The symptom-report corpus recorded in this snapshot is what put this symptom on the page for this brand and appliance.
Documented- amazon-reviews — amazon-reviews, fetched 2026-09-02
Other symptoms covered for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
