C1277 · blink 87 – Test mode: RR sensor interval

System: ABS (test mode only)
Dashboard light: ABS warning light
Check-engine blink code: 87
Applies to: M300/M301 export
Description: Test mode: RR sensor interval
Detection / symptoms: Only in sensor test mode
Possible causes: Test mode: RR sensor interval
What to check: Drive straight 4-7 km/h (electrical) or 10-40 km/h for >=5 s (interval) to clear
Confidence: high

From the factory service material. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights