Chassis, generic

C0860 Trailer Stability Assist Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

No carmaker documents C0860 openly, and it does not appear in any accessible list. The title names trailer sway control, an extra function of the stability control that uses the existing ESC sensors to spot a swinging trailer and then brakes single wheels and trims engine torque until the combination calms down. A Bosch patent detects sway as the gap between target and measured yaw rate, filtered to roughly 0.5 to 1.5 Hz so that normal steering is ignored, and can counter it by shifting drive torque between rear wheels instead of braking. A performance fault means the function cannot work as intended. Acura shows how makers label this: on the 2007-11 MDX the warning for trailer stability assist lit up together with codes 59-1, 66-1, 67-1 or 69-1, and a faulty brake pedal position switch was to blame.

Likely causes

Fault in an ESC input such as brake pedal switch, yaw or wheel speed signal
Trailer not recognised because of trailer socket or wiring faults
Stability control software or configuration needing an update

Symptoms

  • Trailer stability or ESC warning lamp on
  • No automatic braking when the trailer sways

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–600
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

abs control moduleyaw rate sensorbrake light switch

Related codes

C0727C0784C0196

References: bosch-mobility.com, patents.google.com, static.nhtsa.gov.