Samsung’s washer support article lists its error codes and, further down the same page, a handful of entries that are not problems at all: modes the washer has entered, reminders it is giving, and one pause it takes on its own. They sit in the same font on the same display as a real error, which is why they generate calls. Here is what each one is and what to do about it.
SUd, Sd, SUdS and 5Ud
Samsung calls this the excessive suds error, but its own description is that the washer has detected an over-sudsing condition and is pausing while the foam settles. The cycle resumes by itself. Too much detergent is the usual cause, followed by a detergent that is not a high-efficiency formula in a machine that expects one. Nothing has failed. Use less next time, and if the notice appears on every load with the right detergent and the right dose, the drain path is worth checking, because suds that cannot leave the tub keep triggering the sensor.
CL: Child Lock
CL means Child Lock is active, and the smiling-face icon Samsung uses for it will usually be lit as well. The panel ignores presses because it was told to. The way out is a button combination held for a few seconds, marked on the panel and named in the manual for your model; it differs between front-load and top-load machines, so use the manual rather than a guess. A power cut will not necessarily clear it; the lock state is kept deliberately.
dn: Downloading
A Samsung washer connected to the SmartThings app can receive firmware, and while that download is running the display shows dn. Samsung’s instruction is to leave the machine powered and connected until it finishes and restarts on its own. The one thing that can turn a routine update into a control problem is interrupting it, so do not unplug the washer or flip its breaker while dn is showing.
Cb and C6: Calibration Mode
Cb, or C6 on a seven-segment display, shows that calibration mode is running, the routine Samsung uses to recalibrate the weight detection. It is entered from the panel and runs with an empty drum for a couple of minutes. It appears after installation or after the washer has been moved, and if you see it by accident, letting it finish does no harm. Nothing is failing and nothing needs resetting afterwards.
AP: Access Point
AP shows while the washer is acting as a wireless access point so a phone can pair with it during app setup. If you were not setting up the app, switching the washer off and on again leaves the mode. It is the same notice Samsung uses on its dishwashers and refrigerators for the same purpose.
The Self Clean Reminder
On models without a digital display, a lit Self Clean light reminds you that a fixed count of cycles has run since the tub was last cleaned. Samsung states plainly that this is not an error. Run the Self Clean or Pure Cycle program with the drum empty and the reminder clears.
When One of These Hides a Real Problem
The notices above are harmless in themselves, but two situations deserve a closer look. A SUd pause that appears with a code from the drain group, 5C, 5E or nd, after it means the suds were a sign and the drain is the problem. And a dn that is still on the display a day later means the download has stalled; Samsung’s own advice is to contact support at that point rather than keep waiting. In either case, book a Samsung washer repair and tell us both messages in the order they appeared.