HomeTrouble CodesC0592

C0592 — Brake Booster Motor B Phase U V W Current High

Generic OBD-II · all makesChassis

Code C0592 indicates that the powertrain control module (PCM) has detected an abnormally high current draw in one or more phases (U, V, W) of the brake booster motor B. This typically points to a short circuit, a failing motor, or a control module issue within the electric brake booster system.

Symptoms

What causes it — most likely first

1. Faulty brake booster motor

The motor itself may have internal winding shorts or a seized rotor, causing excessive current draw in one or more phases.

2. Short circuit in motor wiring or connector

Damaged insulation, chafed wires, or a corroded/pinched connector can create a direct short to ground or between phases, raising current.

3. Failed brake booster control module

The module that drives the motor may have a shorted power transistor or internal fault, causing uncontrolled high current.

4. Low battery voltage or poor ground

Insufficient voltage or a bad ground can cause the motor to draw higher current as it tries to compensate, though this is less common.

5. PCM/ECM software or hardware fault

Rarely, the PCM itself may misread current or command excessive motor operation. This is the least likely cause and should only be considered after all other components are verified.

How it's diagnosed

  1. Scan the vehicle for all stored codes and freeze frame data to confirm C0592 and check for related codes.
  2. Visually inspect the brake booster motor wiring and connector for damage, corrosion, or loose pins.
  3. Measure resistance between each motor phase (U, V, W) and ground, and between phases, comparing to manufacturer specifications.
  4. Check battery voltage and ground connections at the brake booster control module and motor.
  5. If wiring and voltage are normal, test the brake booster motor by applying a known-good power source (if safe) or swapping with a known-good unit.
  6. If motor and wiring check out, test or replace the brake booster control module; only consider PCM replacement as a last resort after all other possibilities are exhausted.

Code facts & related codes

SystemChassis
StandardizationSAE generic — identical on every make

Frequently asked

Can I drive my car with code C0592?

It is not recommended. The code indicates a high current condition that could lead to brake booster failure, reduced braking assist, or even a fire risk. Have the vehicle diagnosed and repaired promptly.

Is replacing the PCM the fix for C0592?

Almost never. The PCM is rarely the cause of this code. The problem is almost always in the brake booster motor, its wiring, or the dedicated brake booster control module. Replacing the PCM without proper diagnosis is a costly mistake.

What does 'Phase U V W' mean?

It refers to the three electrical phases of the brushless DC motor that drives the brake booster. The code means the current in one or more of these phases is higher than the expected range.

How much does it cost to fix code C0592?

Costs vary widely depending on the root cause. A simple wiring repair may be inexpensive, while replacing the brake booster motor or control module can be several hundred dollars. Diagnosis by a qualified technician is essential to avoid unnecessary parts replacement.