Faulty brake booster travel sensor; Damaged or corroded wiring harness at the sensor connector; Open or shorted circuit in the sensor wiring; Poor electrical connection at the ABS control module; Failed ABS control module; Brake booster pushrod misadjusted or mechanically binding

DTC codes / C00xx · Brakes, steering and suspension / C0048

C0048Brake Booster Travel Sensor

Q: What does code C0048 mean?

Brake Booster Travel Sensor. C0048 indicates that the antilock braking system (ABS) control module has detected a fault in the brake booster travel sensor circuit, which monitors the position of the brake booster pushrod to determine how far the brake pedal has been applied. The computer compares the sensor's voltage signal against expected values and sets this code when the signal is out of range, erratic, or missing entirely.

C0048 indicates that the antilock braking system (ABS) control module has detected a fault in the brake booster travel sensor circuit, which monitors the position of the brake booster pushrod to determine how far the brake pedal has been applied. The computer compares the sensor's voltage signal against expected values and sets this code when the signal is out of range, erratic, or missing entirely.

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 also on
Often no symptoms besides the warning light
Reduced or disabled ABS function during hard braking
Brake pedal feels normal but cruise control may deactivate
In some cases, a soft or inconsistent brake pedal feel

Common causes, most likely first

Faulty brake booster travel sensor
Damaged or corroded wiring harness at the sensor connector
Open or shorted circuit in the sensor wiring
Poor electrical connection at the ABS control module
Failed ABS control module
Brake booster pushrod misadjusted or mechanically binding

How to diagnose and fix it

Scan all modules for stored and pending codes to confirm C0048 is current and not history
Inspect the brake booster travel sensor connector and wiring for corrosion, chafing, or loose pins
Measure sensor reference voltage and ground at the connector with a multimeter
Check sensor signal voltage while slowly pressing the brake pedal to verify smooth sweep
Compare live sensor data on a scan tool against the service manual specification
Replace the brake booster travel sensor if signal is out of range or erratic
Clear codes and perform a road test to verify the repair and confirm the light stays off

What the brake booster travel sensor really does

The brake booster travel sensor is often confused with the brake pedal position sensor, but they are separate components and a failure in one will not always set a code for the other.
A weak or failing battery can cause intermittent voltage drops that mimic a sensor fault, so always check charging system health before condemning the sensor.
On many vehicles the ABS module shares a ground with other chassis electronics, and a corroded ground point can set C0048 along with unrelated codes.
The sensor is frequently misdiagnosed as a bad ABS module when the actual problem is a chafed wire near the booster that only shorts when the engine moves under load.
After replacing the sensor, some vehicles require a calibration or relearn procedure through the scan tool, and skipping it will leave the code stored.

Can I keep driving with C0048?

The vehicle remains safe to drive under normal conditions because the base brakes still work, but avoid hard braking or emergency stops until the fault is repaired since ABS may not engage. If the brake pedal feels abnormal or the warning light is accompanied by a red brake light, 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.