C0201Brake Fluid Level Switch Circuit
- Generic OBD-II code · Chassis
- How the car detects it
- Searches of J2012 tables, NHTSA bulletins and maker indexes found no trace of C0201, so no vehicle use can be shown; GM files its low-fluid input under C0128. The title concerns the wiring of the float switch fitted to the master cylinder reservoir. On the Saab 9-5 that switch sits in the filler cap: a float with two contacts closes once the level has dropped to about two thirds and grounds the warning lamp, which the cluster also lights for 3 s at key-on as a bulb check. A Nabco/Nissan patent places a reed switch under the reservoir floor, worked by a magnet in the float, with a push-down test. Under FMVSS 135 the driver must be warned once any chamber drops under the maker's safe mark or one quarter of its capacity. A circuit code points to a broken lead, a corroded plug or an internally shorted switch.
- What you may notice
- Red brake warning lamp on or flickering
- Low-fluid message although the reservoir is full
- Likely causes
- LikelyCorroded or loose connector at the reservoir cap or switch
- PossibleLevel switch shorted or open internally, float stuck
- PossibleChafed wiring between switch and module
- RareActually low fluid from worn pads or a leak
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €150
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.