C0301Air Suspension Compressor Relay
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- No reachable J2012 table, no GM keyword list such as PIP5094, no AA1Car chart and no NHTSA bulletin carries C0301. Makers that document this fault use their own numbers. Mercedes-Benz stores open-circuit compressor actuation on AIRMATIC cars as C1562 and, after moisture froze in the compressor and the start current blew the 40 A fuse, replaces compressor, fuse and relay together. Lexus reports C1752 on the 2013–17 LS460 when water corrodes the height control compressor, and Volvo tells dealers to swap fuse and compressor on 2017–18 models. The relay switches the compressor's heavy current on command of the suspension module. A worn compressor overloads its contacts; a relay that sticks closed keeps it running and can overheat it.
- What you may notice
- Air suspension warning message, compressor silent
- Vehicle sinks or leans after standing
- Compressor runs continuously when the relay sticks
- Likely causes
- LikelyRelay contacts burnt or welded by excessive compressor current
- PossibleWorn, seized or water-damaged compressor drawing too much current
- PossibleBlown compressor fuse or corroded relay socket and wiring
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.