C0201 code meaning
Brake Fluid Level Switch Circuit
What C0201 means
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.
C0201 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0201
- Red brake warning lamp on or flickering
- Low-fluid message although the reservoir is full
Common causes of C0201
- Most likelyCorroded or loose connector at the reservoir cap or switch
- PossibleLevel switch shorted or open internally, float stuck
- PossibleChafed wiring between switch and module
- Less likelyActually low fluid from worn pads or a leak
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake fluid level switchBrake fluid reservoirABS control module
What each part of C0201 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 01 | The exact fault in that area. |
What to do next
- Note C0201 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0201
What does C0201 mean?
C0201 means "Brake Fluid Level Switch Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with C0201?
C0201 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will C0201 fail an emissions test?
C0201 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0201 to fix?
Difficulty: easy. A typical repair takes 0.2 to 1 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will C0201 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.