OBD Guide

P123B

BARO Sensor / TC/SC Boost Pressure Sensor 'B' Correlation

P123B is an OBD-II diagnostic trouble code meaning: BARO Sensor / TC/SC Boost Pressure Sensor 'B' Correlation. Common causes: atmospheric pressure sensor (baro) malfunction, boost pressure sensor 'b' faulty. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced engine power
  • Unstable engine operation
  • Increased fuel consumption
  • The engine goes into emergency mode

Causes

  • Atmospheric pressure sensor (BARO) malfunction
  • Boost pressure sensor 'B' faulty
  • Problems with sensor wiring or connectors
  • Leaks in the boost system
  • Problems with the engine ECU

How to Fix

  1. Check the atmospheric pressure sensor readings
  2. Check boost pressure sensor 'B'
  3. Inspect the wiring and sensor connectors
  4. Check the system for leaks
  5. If necessary, replace faulty sensors

Related codes

FAQ

What does the P123B code mean?

P123B is an OBD-II diagnostic trouble code that indicates: BARO Sensor / TC/SC Boost Pressure Sensor 'B' Correlation

What causes a P123B error code?

The most common causes of P123B include: Atmospheric pressure sensor (BARO) malfunction; Boost pressure sensor 'B' faulty; Problems with sensor wiring or connectors; Leaks in the boost system.

How do I fix a P123B diagnostic trouble code?

To fix P123B: Check the atmospheric pressure sensor readings. Check boost pressure sensor 'B'. Inspect the wiring and sensor connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P123B?

Yes, but get it checked soon

How much does it cost to fix P123B?

The estimated repair cost for P123B is $33–167. Actual cost depends on your vehicle, location, and labor rates.

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