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ROBOROCK·FAULT ERR 4 WARN

Roborock Error 4 — Cliff sensor error

Severity: Warning — robot stops because it can't trust its drop sensors S5S6S7S8Q
Last verified: 2026-07-05 Tools: soft dry cloth Time: ~5 min Difficulty: easy

DIRECT ANSWER

Error 4 means the cliff sensors report nonsense — usually because they're dusty, the robot is hanging over a drop, or it's sitting on very dark carpet. Wipe the sensors and move the robot away from edges.
#meaning · #causes · #fix — link straight to any section

COMMON CAUSES · RANKED

1

Dusty cliff sensors MOST COMMON

A film of dust over the sensor windows under the front edge makes the floor invisible to the robot.

2

Robot over a raised edge

Parked half over a stair or ledge, the sensors correctly see a drop and stop everything.

3

Dark or shag carpet

Very dark or deep-pile carpet absorbs the infrared signal and reads as a cliff. Roborock confirms this trigger officially.

HOW TO FIX IT

No battery or electrical work involved in this fix.

Wipe all cliff sensors

Flip the robot and wipe every sensor window along the front underside with a soft dry cloth.

Move away from drops

Set the robot down at least a metre from stairs or ledges and restart.

Test off the dark carpet

If the error only fires on a black or shag rug, start the robot on hard floor and fence the rug off with a no-go zone.

RELATED FIRMWARE

S5 series (S5)

SAMPLE DATA — dataset in progress
3.3.9_0017683.5.4_0019103.5.7_0020083.5.8_0020203.5.8_002034

Firmware timelines are rebuilt monthly from release notes. Versions marked as sample data are community-reported and not yet verified. Full firmware timeline →

Sources

Verification

OFFICIAL SOURCE

Last verified: 2026-07-05 · How we verify a fault code

Corrections

Spotted an error? Report a correction — fixes ship within 48h and are logged on this page.