Faulty brake pressure sensor E; Short to voltage in the sensor signal circuit; Damaged or corroded wiring harness or connector at the sensor; Water or debris intrusion into the sensor connector; Faulty ABS control module (less common); Poor ground connection for the sensor circuit

DTC codes / C05xx · Brakes, steering and suspension / C05A0

C05A0Brake Pressure Sensor E Circuit High

Q: What does code C05A0 mean?

Brake Pressure Sensor E Circuit High. The antilock braking system (ABS) module has detected an abnormally high voltage on the electrical circuit for brake pressure sensor E, which is one of several pressure sensors used to monitor hydraulic brake pressure. This high signal can be caused by a short to voltage, a faulty sensor, or wiring problems, and it may disable the ABS and traction control systems.

The antilock braking system (ABS) module has detected an abnormally high voltage on the electrical circuit for brake pressure sensor E, which is one of several pressure sensors used to monitor hydraulic brake pressure. This high signal can be caused by a short to voltage, a faulty sensor, or wiring problems, and it may disable the ABS and traction control systems.

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
Reduced or disabled antilock braking function during hard braking
Possible erratic brake pedal feel or reduced power assist in some cases

Common causes, most likely first

Faulty brake pressure sensor E
Short to voltage in the sensor signal circuit
Damaged or corroded wiring harness or connector at the sensor
Water or debris intrusion into the sensor connector
Faulty ABS control module (less common)
Poor ground connection for the sensor circuit

How to diagnose and fix it

Use a scan tool to read ABS codes and verify C05A0 is current, then check for related codes
Inspect the brake pressure sensor E and its connector for corrosion, damage, or loose pins
Measure reference voltage and signal voltage at the sensor connector with a digital multimeter
Check the signal circuit for a short to voltage by measuring voltage with the sensor disconnected
Test the sensor resistance or output according to manufacturer specifications
If wiring and sensor test good, check the ABS module connectors and grounds
Replace the faulty sensor or repair wiring as needed, then clear codes and verify repair

What most technicians overlook with C05A0

A short to voltage in the signal circuit often comes from chafed wiring near the brake master cylinder or ABS pump, where vibration and heat are common.
The brake pressure sensor may share a reference voltage or ground with other sensors, so a fault in one can set multiple pressure sensor codes.
Some vehicles use the brake pressure sensor for hill-start assist and stability control, so a failure can cause those systems to be disabled even if the ABS light is the only warning.
A weak or failing battery or charging system can cause voltage spikes that trigger this code intermittently, so always check system voltage first.
After replacing the sensor, some vehicles require a calibration or relearn procedure for the ABS module to recognize the new sensor.

Can I keep driving with C05A0?

You can usually drive the vehicle with the warning light on, but the antilock braking system and traction control may be disabled, increasing stopping distances in slippery conditions. Avoid hard braking and have the fault diagnosed promptly to restore full safety system function.

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.