C064C code meaning
Brake Pressure Sensor M Range/Performance
What C064C means
Sensor M stays inside its electrical window, but the pressure it reports is not believable. Trailer EBS shows an active test: when the control pressure exceeds 0.3 bar, WABCO's modulator switches its redundancy valve to reservoir pressure and starts EBS braking; during the stop it briefly switches back and uses its internal actual-pressure sensors to confirm that pneumatic pressure is present, otherwise it changes to purely pneumatic braking. Kelsey-Hayes lists in-range checks for hydraulic sensors: high pressure lasting unusually long, or high pressure while the brakes are not applied. No carmaker documents C064C or says which sensor is M. Possible causes: drift, a sticking valve, a leak, contamination in the sensor port.
C064C at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of C064C
- Warning lamp on after a brake application
- Braking switched to a backup mode with less precise pressure control
Common causes of C064C
- Most likelySensor reading drifted from the true pressure
- PossibleValve in the measured circuit not switching as commanded
- Less likelyContamination or air at the sensor port
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake pressure sensor m
What each part of C064C means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4C | The exact fault in that area. |
What to do next
- Note C064C 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 C064C
What does C064C mean?
C064C means "Brake Pressure Sensor M Range/Performance". Sensor M stays inside its electrical window, but the pressure it reports is not believable. It is a generic code, so it means the same on every make.
Is it safe to drive with C064C?
Drive gently and only to a workshop. With C064C the car can go into limp mode (reduced power) to protect itself.
Will C064C fail an emissions test?
C064C 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 C064C to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will C064C clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.