Why did P0048 appear after work on my engine?

Often because a connector near the turbo or intake was not pushed fully home, or a wire was pulled or pinched while parts were removed and refitted. An open circuit makes the control circuit read high. Check the plugs and the harness around the work area before buying parts.

Can I drive with P0048?

Only gently and only to a workshop. Most engines go into limp mode and cut boost, so acceleration is slow and power can drop under load. Avoid motorways, overtaking and towing until it is fixed.

What is the difference between P0047 and P0048?

Both are electrical faults in the boost control circuit. P0047 means the voltage is too low, usually a short to ground or a shorted solenoid coil. P0048 means it is too high, usually an open circuit, an unplugged connector or a short to voltage. P0046 is different: the circuit works but boost does not follow the command.

How much does it cost to fix P0048?

Cleaning and reseating the connector costs nothing to 50 euros. A wiring or connector repair runs 70 to 220 euros, mostly fault-finding time, and a new boost control solenoid 50 to 170 euros fitted. On engines with an electronic turbo or wastegate actuator, a new actuator costs 140 to 500 euros.

P0048: Turbocharger/Supercharger Boost Control "A" Circuit High

Quick Answer

Not safe to drive

P0048 means the engine computer has found a voltage on the control circuit of boost control device "A" that is higher than it should be. That device is usually the boost pressure control solenoid that feeds vacuum to the turbo actuator, or on some engines an electronic turbo or wastegate actuator. A high reading usually points to an open circuit, an unplugged or damaged connector, a solenoid coil that has gone open, or a wire shorted to a voltage supply. With the control circuit faulty, the engine computer normally limits boost and power.

Severity: Moderate · Fuel System

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What does P0048 mean?

P0048 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0048 and illuminates the check engine light.

Where it is on the car

Air filter
Turbocharger
Wastegate or boost control actuator
Intercooler
Boost pressure sensor
Throttle, intake manifold and engine

What are the symptoms of P0048?

If your vehicle has triggered P0048, you may notice one or more of these symptoms:

Check engine light on, often with a reduced power message
Limp mode with power capped, especially under load
Flat, slow acceleration because boost no longer builds
Black smoke under acceleration on some diesels
Code returning straight after clearing, often as soon as the engine starts

What causes P0048?

Here are the most common causes of P0048:

Open circuit in the solenoid coil, so no current flows when the engine computer switches it
: high
Connector unplugged, not fully latched or corroded at the solenoid or actuator
: high
Broken control wire between the solenoid and the engine computer
: medium
Control wire shorted to a voltage supply
: medium
Failed electronic turbo or wastegate actuator, on engines that use one
: medium
Engine computer output fault (rare)
: low

Is it safe to drive with P0048?

No - address this immediately. Drive gently and only as far as a workshop. Most engines go into limp mode with this code because the engine computer can no longer control boost properly, and power can drop suddenly under load. Avoid motorway merging, overtaking and towing until the fault is repaired.

How do you diagnose P0048?

Follow these steps to pinpoint the root cause of P0048:

Read all stored codes and the freeze frame. P0299 stored alongside shows that boost really dropped while the circuit was faulty. A generic OBD2 reader shows the codes, the freeze frame and boost or MAP readings where the engine computer reports them.
Find out what boost control device "A" is on your engine: on many diesels and older turbo petrols it is a vacuum solenoid mounted near the turbo or on the bulkhead, and on many newer engines it is an electronic actuator on the turbo itself. Check the workshop information for your engine code.
Check that the connector is pushed fully home and latched, then unplug it and inspect for corrosion and damaged pins. A connector left loose after work near the turbo or intake is a common trigger.
Measure the solenoid coil resistance and compare it with the specification for your engine. No continuity at all means the coil has gone open.
Check the control wire for continuity back to the engine computer, and with the ignition on check that it is not carrying battery voltage from a short to another wire.
Repair the wiring or replace the solenoid or actuator. Commanding the solenoid or sweeping an electronic actuator to test it, and adapting a new electronic actuator, need manufacturer-level software; a generic OBD2 reader cannot do this. Clear the code and road-test under load.

How much does P0048 cost to fix?

Repair costs for P0048 vary depending on the root cause and your vehicle. Here are typical estimates:

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Clean and reseat solenoid or actuator connector	€0–€10	€0–€40	€0–€50	Easy
Repair solenoid or actuator wiring or connector	€10–€40	€60–€180	€70–€220	Moderate
Replace boost control solenoid	€20–€80	€30–€90	€50–€170	Easy
Replace electronic turbo or wastegate actuator	€60–€250	€80–€250	€140–€500	Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0048 or indicate related issues:

Common questions about P0048

What does P0048 mean?: P0048 means the control circuit of boost control device "A", usually the boost pressure control solenoid or an electronic turbo actuator, is reading a higher voltage than it should. It is an electrical fault in that circuit, most often an open circuit, an unplugged connector, a failed solenoid coil or a short to voltage.
Why did P0048 appear after work on my engine?: Often because a connector near the turbo or intake was not pushed fully home, or a wire was pulled or pinched while parts were removed and refitted. An open circuit makes the control circuit read high. Check the plugs and the harness around the work area before buying parts.
Can I drive with P0048?: Only gently and only to a workshop. Most engines go into limp mode and cut boost, so acceleration is slow and power can drop under load. Avoid motorways, overtaking and towing until it is fixed.
What is the difference between P0047 and P0048?: Both are electrical faults in the boost control circuit. P0047 means the voltage is too low, usually a short to ground or a shorted solenoid coil. P0048 means it is too high, usually an open circuit, an unplugged connector or a short to voltage. P0046 is different: the circuit works but boost does not follow the command.
How much does it cost to fix P0048?: Cleaning and reseating the connector costs nothing to 50 euros. A wiring or connector repair runs 70 to 220 euros, mostly fault-finding time, and a new boost control solenoid 50 to 170 euros fitted. On engines with an electronic turbo or wastegate actuator, a new actuator costs 140 to 500 euros.

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