OBD Guide

C054B

Vacuum Sensor A Circuit Low

C054B is an OBD-II diagnostic trouble code meaning: Vacuum Sensor A Circuit Low. Common causes: faulty vacuum sensor, open or short circuit in wiring harness. Estimated repair cost: $22–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–167 (est.)

Symptoms

  • Check Engine Light Is On
  • Unstable engine idling
  • Increased fuel consumption
  • Reduced engine power
  • Problems with the brake booster (if the sensor is connected to the brake system)

Causes

  • Faulty vacuum sensor
  • Open or short circuit in wiring harness
  • Poor contact in the sensor connector
  • Damage to the wiring from the sensor to the ECU
  • Problems with power supply or sensor ground
  • ECU malfunction (rare)

How to Fix

  1. Check the integrity and supply voltage of the sensor (usually 5V)
  2. Check sensor resistance and signal to specifications
  3. Inspect the wiring harness for damage
  4. Check the contacts in the sensor and ECU connectors for corrosion and connection reliability
  5. If necessary, replace the vacuum sensor

Related codes

Error C054B by Vehicle Brand

FAQ

What does the C054B code mean?

C054B is an OBD-II diagnostic trouble code that indicates: Vacuum Sensor A Circuit Low

What causes a C054B error code?

The most common causes of C054B include: Faulty vacuum sensor; Open or short circuit in wiring harness; Poor contact in the sensor connector; Damage to the wiring from the sensor to the ECU.

How do I fix a C054B diagnostic trouble code?

To fix C054B: Check the integrity and supply voltage of the sensor (usually 5V). Check sensor resistance and signal to specifications. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C054B?

Limited driving only, diagnose soon

How much does it cost to fix C054B?

The estimated repair cost for C054B is $22–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat