Turbo and forced inductionGeneric OBD-II codeUrgency: Garage soon
Code P0243: turbo wastegate solenoid valve: fault
P0243 means: turbocharger wastegate solenoid "A": malfunction.[1][2][3] The ECU has detected a fault in the control circuit of the turbo's wastegate solenoid (solenoid valve) "A". The wastegate acts as the turbo's safety system, because it reduces boost pressure by diverting gases, and this solenoid valve is what allows the ECU to regulate it: if it fails, the turbo may give insufficient or excessive pressure. Some manufacturers describe it as the "turbocharger bypass valve circuit A".[1][2][4]
What code P0243 means
The ECU has detected a fault in the control circuit of the turbo's wastegate solenoid (solenoid valve) "A". The wastegate acts as the turbo's safety system, because it reduces boost pressure by diverting gases, and this solenoid valve is what allows the ECU to regulate it: if it fails, the turbo may give insufficient or excessive pressure. Some manufacturers describe it as the "turbocharger bypass valve circuit A".[1][2][4]
In Saab's workshop manual for the 2011 9-5 2.0 turbo, the solenoid valve is controlled with a pulse-width modulated (PWM) signal and the code is stored when the ECU detects, for more than 2 seconds, an open circuit, a short to earth or a short to positive in its control circuit. The ECU responds by disabling pressure control and leaving only the turbo's mechanical pressure, with a noticeable loss of power.[3]
It is an "actuator" code, not a result code: it does not say how much pressure the turbo is giving, but that the solenoid valve circuit is faulty. P0245 and P0246 (circuit with low or high voltage) share a page and conditions with P0243 in the Saab manual. A German workshop explains, regarding P0245 (the same circuit), that a faulty solenoid valve can end up causing a P0299 (insufficient pressure) or a P0234 (excessive pressure), so it is worth reading all the stored codes.[3][5]
It is a generic OBD-II code (it starts with P0), so its definition is the same on any make; what changes from one engine to another is the most likely cause and the names of the parts.[6]
Original definition (SAE J2012): Turbocharger Wastegate Solenoid A Malfunction[1][2][3]
Codes from the same family
They indicate the same problem in a specific cylinder, bank or sensor. Causes, symptoms and diagnosis are those on this page.
- P0243Turbocharger wastegate solenoid "A": malfunction.
- P0245Turbo wastegate solenoid valve circuit "A": low signal.[1]
Causes of P0243 and its family
From most to least likely, according to the sources.
- 1Faulty wastegate solenoid valve, for example with a failed coil.[1][3][5][7]
- 2Wiring, connectors or earth of the control circuit in poor condition: open circuit, short to earth or to positive, corroded or loose connections.[1][3][5][7]
- 3Damaged or leaking vacuum or pressure hoses to the actuator.[1][5][7]
- 4Stuck or damaged wastegate actuator, or a mechanical defect in its servo.[1]
- 5Faulty engine ECU, for example the stage that drives the solenoid valve.[1][3][5]
- 6Leaking exhaust: only CarWiki cites it.[7]
Symptoms
- Engine warning light on in the instrument cluster.[7]Engine warning light: faults that cause it
- Loss of power, especially at high revs.[1][3][7]Less power: faults that cause it
- The ECU disables pressure control and leaves only the turbo's mechanical pressure, or the engine goes into limp-home mode, with power limited.[1][3][7]Limp mode: faults that cause it
- Weak response when you press the accelerator.[7]
- Excessive boost pressure.[1]
- Whistling or other abnormal noises around the turbo.[1]Turbo whistle: faults that cause it
- Black smoke from the exhaust.[1]Black smoke: faults that cause it
- Rough idle or starting problems.[1]Vibrations: faults that cause it
How to diagnose P0243
In order: from the most likely and cheapest to check to the most expensive.
- 1Read all the stored codes (for example P0245, P0246, P0299 or P0234) and the live data: requested versus actual boost pressure and the duty cycle with which the ECU drives the solenoid valve.[5]
- 2Visually check the solenoid valve connector and wiring, including its earth: loose or corroded connections, damaged wires.[1][5][7]
- 3Inspect the vacuum or pressure hoses running from the solenoid valve to the wastegate actuator: cracks, hardening, disconnections or leaks.[1][5][7]
- 4Activate the solenoid valve with the diagnostic tool (actuator test) and check that it responds: in the Saab manual it is commanded to 50 % and the test lamp should flash, and KFZ Dietrich checks that the duty cycle follows the requested value and that the valve switches audibly.[3][5]
- 5With the connector unplugged, use a test lamp or a multimeter to check that power reaches the solenoid valve with the ignition on and that the control circuit has no shorts or high resistance; also measure the coil resistance and the continuity of the wires to the ECU.[3][5][7]
- 6Check that the wastegate actuator and flap move freely through their whole travel, without sticking, and that the exhaust has no leaks.[1][5][7]
- 7If the circuits are fine, replace the solenoid valve; if the fault is in the control circuit, check the ECU. The turbo is left until last.[3][5]
Can I keep driving with P0243?
Garage soon
The sources do not fully agree. Autodoc Club says you can only keep driving up to a point and recommends repairing the car as soon as possible, because the turbo can be damaged if the wastegate does not work properly. KFZ Dietrich, regarding P0245 (the same circuit), considers short trips to the workshop acceptable as long as the engine runs normally and the warning light stays steady, but says that if the light flashes, there is a noticeable loss of power or the engine goes into limp-home mode, you must stop and ask for a diagnosis. In the Saab manual, the ECU limits the engine to the turbo's mechanical pressure, with a noticeable loss of power.[1][3][5]
Documented faults related to P0243
Known faults of specific engines and cars, with their repair cost, the affected years and their sources.
Turbo: the most serious faults by engine and car
- High severityFrequency: Very frequent1.6 HDiTurbo failure through lack of lubrication (carbon deposits and union filter)On the 16-valve 1.6 HDi/TDCi engines (2004-2011) the turbo can seize because carbon deposits from the oil clog the mesh filter in the union that feeds it. It is a serious, repeat fault: if only the turbo is replaced without cleaning the circuit, it fails again.Repair (garage): €700–€1,050
- High severityFrequency: Very frequent2.0 Ingenium diéselTurbocharger failureYes: according to several sources, the turbo is the component that causes the most faults on the 2.0 Ingenium diesel. It fails across a very wide mileage range (from around 35,000 to over 140,000 km) and, if it breaks up inside, it can send oil or metal into the engine and destroy it.Repair (garage): €2,600–€3,000Appears at around 35,000 km
- High severityFrequency: CommonBMW N47Turbo and wastegate valve failureThe N47's turbo does not usually fail from general wear, but because of failure of the wastegate valve, which regulates boost and can seize or lose adjustment, sending fuel consumption soaring; oil leaks from the turbo itself are also common.Repair (garage): €900–€1,800
- High severityFrequency: CommonOM651Variable-geometry turbo failure and its pneumatic actuatorThe OM651's variable-geometry turbo tends to fail at the pneumatic actuator (cracks, loss of calibration) before the turbo itself. Symptoms range from a gradual loss of power to permanent limp mode, with whistling or smoke if the problem progresses.Repair (garage): €500–€3,000
Wiring, connectors and short circuits: the most serious faults by engine and car
- Critical severityFrequency: OccasionalBMW N62 / N63Additional turbo coolant pump with a risk of short circuit and fireIn 2011 BMW recalled 5, 6 and 7 Series, X5 and X6 models built between 2007 and 2011 because of the additional turbo coolant pump: moisture, a short circuit and, in extreme cases, a fire. In 2012 there was another campaign for a crack in the pump, with a more robust version.
- High severityFrequency: Occasional1.3 TCeBlown fuel pump fuseOn the Renault Captur II and Clio V with the 1.3 TCe engine, a 20-amp fuse can blow and leave the car without an engine. According to L'argus, in April 2021 this fault still had no factory fix; the official service centre's diagnosis includes checking, and sometimes replacing, the catalytic converter.
- High severityFrequency: OccasionalM264/M254Poorly tightened 48 V earth wiring in the mild-hybrid system (fire risk)Mercedes-Benz has issued several recalls (2022-2025) because the 12 V and 48 V earth connections of some cars with a 48 V system may be poorly tightened: resistance rises, the connection heats up and a fire cannot be ruled out. The official workshop checks them and repairs them if necessary in an hour or more.
- High severityFrequency: Occasional1.9 TDIUnit injector tappet wear and injector wiring damageOn the unit injector system, the tappets that operate the injectors can wear if the oil is not changed on time, and the injector wiring can be damaged by contact with oil, causing misfires or loss of power.
- Critical severityFrequency: CommonRover 75Seat SRS connector fault with airbag and seatbelt warning light onAuto Express warns that the Rover 75's seat SRS connector can cause the airbags to fail, and dealers were fixing it with revised connectors. The Dutch APK inspection puts the airbag or seatbelt fault warning among the most frequent defects across almost all series.
- Critical severityFrequency: OccasionalAlfa Romeo GiuliettaShort circuit from badly routed wiring that can prevent gear shifting (KBA campaign, 2010-2015)Yes: according to Germany's KBA, on Alfa Romeo Giulietta cars built between 2010 and 2015 inadequate cable routing could cause a short circuit and, as a result, gear-shift failure.
Frequently asked questions
Can I drive with code P0243?
Only as far as needed to reach the garage, and gently. Autodoc Club says you can keep driving only up to a point and that the turbo can be damaged if the wastegate does not work properly. KFZ Dietrich, regarding P0245 (the same circuit), considers short trips to the workshop acceptable as long as the engine runs normally and the warning light stays steady, but says that if the light flashes, there is a noticeable loss of power or the engine goes into limp-home mode, you must stop and ask for a diagnosis.[1][5]
How does P0243 differ from P0245, P0246, P0299 and P0234?
P0243, P0245 and P0246 are codes for the wastegate solenoid valve circuit: in the Saab manual they share conditions (open circuit or short to earth or to positive for more than 2 seconds), and P0245 corresponds to low voltage and P0246 to high voltage. P0299 and P0234 describe the result: according to KFZ Dietrich, the boost pressure is below or above the expected level. The same workshop explains that a faulty solenoid valve can be the cause of a P0299 or a P0234, so it is worth reading all the codes before diagnosing.[3][5]
Does the turbo need replacing when P0243 appears?
Not necessarily. The lists of causes start with the solenoid valve, its wiring and connectors, the vacuum hoses and the wastegate actuator; KFZ Dietrich leaves replacing the turbo until last, once those points have been ruled out.[1][5][7]
What is the wastegate and how can you tell it is failing?
Motor.es describes it as a safety system of the turbo that reduces boost pressure by diverting gases; if it stopped working, the turbo could seize and break and the engine could be damaged. Among the signs that it is failing it lists an irregular noise and a lack of power and push when accelerating, and advises consulting the nearest workshop if in doubt. Autodoc adds that P0243 can come with excessive boost pressure, black smoke and whistling.[1][4]
Does P0243 mean the same on all makes?
The definition is the same, because codes starting with P0 are generic OBD-II codes, but the names vary: Autodoc speaks of wastegate solenoid "A" or bypass valve circuit "A", the Saab manual of the wastegate solenoid valve control circuit, and CarWiki of the boost pressure regulator (Ladedruckregler).[1][3][6][7]
Will I pass the MOT with code P0243?
If the code has switched on the engine warning light, no: with that light on, the inspection records a serious defect, and on Euro 5 and Euro 6 cars the ITV (Spain's roadworthiness inspection, similar to the MOT) also reads the OBD diagnostic system. Repair the fault before you go; clearing the code just before the inspection does not help either, because it counts as a serious defect.[8]
Not sure what is wrong with your car? Describe what you notice in the symptom diagnosis or see all fault codes.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- Código OBD2 P0243: causas, síntomas y cómo corregirloAutodoc Club · Technical documentation · consulted 2 October 2026 · in Spanish
- P0243 — Turbocharger Wastegate Solenoid A MalfunctionThe Automotive Technician (TaT) · Technical documentation · consulted 2 October 2026
- DTC P0243, P0245, or P0246 9-5 (9650) 2011Saab Workshop Information System (WIS Online) (copia del manual de taller de Saab) · Technical documentation · consulted 2 October 2026
- Wastegate, qué es y por qué es tan importante que esté en buen estadoMotor.es · Motoring press · published 27 January 2023 · consulted 2 October 2026 · in Spanish
- P0299 vs. P0234 vs. P0245: Resultat oder Stellglied?KFZ Dietrich · Other source · published 4 August 2026 · consulted 2 October 2026 · in German
- On-board diagnosticsWikipedia · Other source · consulted 2 October 2026
- OBD Fehlercode P0243 | Abgasklappenventil TurboladerCarWiki.de · Technical documentation · consulted 2 October 2026 · in German
- Desmontando mitos: ¿puede pasar mi coche la ITV con el testigo de «avería motor» encendido?Diariomotor · Motoring press · published 8 March 2021 · consulted 2 October 2026 · in Spanish