Chassis, generic

C0815 Air Suspension Compressor Overtemperature

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0815 has no public owner: code lists and maker indexes skip it, and the NHTSA index only matches it inside unrelated BMW bulletin IDs. The title names thermal protection of the air suspension compressor. Most systems have no temperature sensor and estimate the heat from running time instead. Continental patents describe two strategies: switching the pump off above a calculated limit and back on only when it has cooled enough for one full level change on a loaded vehicle, or pulsing it near the limit so that a lift of 20 to 30 s can still finish. Long lifts at standstill, frequent level corrections, fast off-road driving and heavy sound insulation heat it most; a leak that keeps it running has the same effect.

Likely causes

Leak in an air spring, line or valve block keeps the compressor running
Repeated manual level changes at standstill or heavy load changes
Worn or moisture-damaged compressor delivering too little air

Symptoms

  • Ride height change stops or is refused for several minutes
  • Air suspension warning, vehicle sits low after long standing

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,400
Time0.5–3 h

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

Parts involved

air compressorair linesair springs

Related codes

C0810C0301C0840

References: patents.google.com, image-ppubs.uspto.gov, static.nhtsa.gov.