P0238 Generic (SAE) Basic entry

Turbo/Super Charger Boost Sensor 'A' Circuit High

Updated 2026-10-02 · Fuel & air metering (injector circuit)

Severity

Medium

Typical repair cost

40 – 350 EUR

System

Powertrain

What it means

P0238 is stored when the engine control module measures a voltage in the Turbo/Super Charger Boost Sensor 'A' circuit above the expected maximum, typically because the signal wire is shorted to battery voltage or the circuit is open and pulled up internally.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

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Symptoms

Check engine light on
Rough or unstable idle
Hesitation or poor acceleration
Increased fuel consumption
Possible limp mode with reduced power

Common causes

Damaged, chafed or corroded wiring in the Turbo/Super Charger Boost Sensor 'A' circuit
Corroded, loose or water-damaged connector terminals
Failed Turbo/Super Charger Boost Sensor 'A' component (sensor, solenoid or actuator)
Poor ground connection for the module or component
Faulty control module driver (rare, confirm all else first)

How to diagnose

Read freeze frame data and note when the code set (cold start, under load, after rain)
Inspect the Turbo/Super Charger Boost Sensor 'A' connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
Measure supply voltage and ground at the connector with the key on
Check the signal wire for shorts to ground or battery and for continuity to the control module
Test or substitute the Turbo/Super Charger Boost Sensor 'A' only after wiring and connectors are confirmed good
Clear the code and complete a drive cycle to confirm the repair

Frequently asked questions

Can I keep driving with P0238?

Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.

Will clearing P0238 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.