Faulty brake pressure sensor on the M circuit; Damaged or corroded wiring harness or connector at the sensor; Contaminated or degraded brake fluid affecting sensor readings; Air trapped in the hydraulic system near the sensor; Failed ABS control module or internal sensor circuit fault; Low brake fluid level or hydraulic leak causing pressure deviation; Mechanical binding or restriction in the brake hydraulic circuit

DTC codes / C06xx · Brakes, steering and suspension / C064C

C064CBrake Pressure Sensor M Range/Performance

Q: What does code C064C mean?

Brake Pressure Sensor M Range/Performance. C064C indicates the antilock braking system (ABS) module has detected that the brake pressure sensor for the 'M' circuit is reporting a signal outside its expected range or performance window. The computer compares the sensor's voltage or pressure reading against other pressure sensors and vehicle operating conditions, and it flags this code when the signal is erratic, stuck, or implausible for the current braking situation.

C064C indicates the antilock braking system (ABS) module has detected that the brake pressure sensor for the 'M' circuit is reporting a signal outside its expected range or performance window. The computer compares the sensor's voltage or pressure reading against other pressure sensors and vehicle operating conditions, and it flags this code when the signal is erratic, stuck, or implausible for the current braking situation.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

ABS warning light illuminated on the dashboard
Traction control or stability control warning light may also be on
Often no symptoms besides the warning light, with normal brake pedal feel
Reduced or disabled ABS function during hard braking
Intermittent warning light that comes and goes with temperature or vibration
Brake pedal may feel slightly different or require more effort in some cases

Common causes, most likely first

Faulty brake pressure sensor on the M circuit
Damaged or corroded wiring harness or connector at the sensor
Contaminated or degraded brake fluid affecting sensor readings
Air trapped in the hydraulic system near the sensor
Failed ABS control module or internal sensor circuit fault
Low brake fluid level or hydraulic leak causing pressure deviation
Mechanical binding or restriction in the brake hydraulic circuit

How to diagnose and fix it

Check brake fluid level and condition; top off or flush if contaminated
Inspect the sensor connector and wiring for corrosion, chafing, or loose pins
Use a scan tool to read live pressure sensor data and compare with a mechanical gauge
Perform a resistance and voltage test on the sensor circuit per manufacturer specifications
Bleed the brake system thoroughly to remove trapped air
Replace the brake pressure sensor if testing confirms it is out of range
Reprogram or replace the ABS control module if the sensor and wiring test good but the code persists

What most technicians overlook on C064C

A low brake fluid level or a small hydraulic leak can cause pressure sensor readings to fall outside the expected range without setting a low-fluid code, so always verify fluid level and inspect for leaks before condemning the sensor.
Corroded or green-tinged pins inside the sensor connector are a frequent cause of intermittent range/performance codes, and cleaning them often resolves the issue without parts replacement.
The ABS module may set C064C when another wheel speed sensor or steering angle sensor is faulty, because the module cross-checks pressure readings against those inputs; always scan all modules for related codes.
After replacing the brake pressure sensor, some vehicles require a calibration or learn procedure for the ABS module, and skipping it can leave the code stored or cause poor pedal feel.
A failing brake pressure sensor can sometimes read within range at idle but drift under heavy braking, so live data should be captured during a road test with hard stops, not just at a standstill.

Can I keep driving with C064C?

The vehicle remains safe to drive under normal conditions because the base hydraulic brakes still work, but ABS and stability control may be disabled, so avoid hard braking or slippery surfaces until the fault is repaired. If the brake pedal feels soft or the fluid level is low, stop driving and have the system inspected immediately.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.