AutoCodes – Generic – P0239

P0239 Code - Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction

Quick Answer

The boost pressure sensor responds to pressure changes in the intake manifold. Common causes include Boost pressure sensor harness is open or shorted, Boost pressure sensor circuit poor electrical connection, Faulty boost pressure sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0239 indicates Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction.
Common causes: Common causes include Boost pressure sensor harness is open or shorted, Boost pressure sensor circuit poor electrical connection, Faulty boost pressure sensor.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 11,462

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0239 Description

The boost pressure sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position (APP) and engine speed. The Engine Control Module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost pressure sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The Engine Control Module (ECM) supplies 5 volts to the boost pressure sensor on the 5-volt reference 2 circuit, and provides a ground on a low reference circuit. The boost pressure sensor provides a signal to the ECM on a signal circuit relative to the pressure changes. The ECM monitors the boost pressure sensor signal for voltage outside of the normal range. The ECM calculates a predicted value for the boost pressure sensor. The ECM then compares the predicted value to the actual signal.

OBDII Code P0239 - Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction - AutoCodes.com — P0239 Code - Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0239?

Boost pressure sensor harness is open or shorted
Boost pressure sensor circuit poor electrical connection
Faulty boost pressure sensor
Faulty Turbo/Super Charger
Engine over temperature
Ignition misfire exceeds the calibrated threshold
Faulty Knock sensor (KS)

How to Fix the DTC P0239?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0239 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P0239 Ford — Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction
P0239 Mercedes-Benz — Turbocharger/Supercharger Boost Sensor 'B' Circuit Malfunction

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.