Turbo and forced inductionGeneric OBD-II codeUrgency: Garage soon
Code P0045: turbo control solenoid: open circuit
What code P0045 means
The ECU has detected an open circuit or an electrical fault in the solenoid that regulates turbo boost pressure, so it cannot control the boost.[1][2]
It is a fault in the valve's electrical circuit, not a mechanical turbo failure; do not confuse it with P0299, which indicates insufficient pressure.[1][2]
Original definition (SAE J2012): Turbocharger/Supercharger Boost Control Solenoid Circuit/Open[1][2]
Causes of P0045
From most to least likely, according to the sources.
Symptoms
- Engine warning light on.[1][2]Engine warning light: faults that cause it
- Loss of power and sluggish response when accelerating.[1][2]Less power: faults that cause it
- Possible turbo pressure warning or power limitation.[2]Limp mode: faults that cause it
- Possible turbo whistle as the pressure drops.[2]Turbo whistle: faults that cause it
How to diagnose P0045
In order: from the most likely and cheapest to check to the most expensive.
- 1Read all the stored codes and look out for other boost codes (P0234, P0299), which help tell an electrical fault from a mechanical one.[2]
- 2Locate the pressure control solenoid and check its wiring and connector: insulation, burnt pins or corrosion.[1][2]
- 3With the ignition off, use a multimeter to measure the coil's continuity and resistance; an open circuit gives infinite resistance.[2]
- 4Check the supply and the ECU's control signal; only if the circuit and the valve are fine, suspect the ECU.[1][2]
Can I keep driving with P0045?
Garage soon
Without boost pressure control the car loses power and may limit it; get it diagnosed soon, although you can normally reach a garage by driving gently.[1][2]
Parts related to code P0045
The parts that most often cause this code. The code points to the circuit, not always the part: diagnose before you buy.
Affiliate links: if you buy from these shops, MotorFiable may receive a commission at no cost to you. Check compatibility against the registration plate or VIN before ordering. More information
Documented faults related to P0045
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.
- Critical severityFrequency: Occasional1.6 GDi híbrido (Kappa)Main relay of the power relay assembly (overheating and fire risk)Yes, on the first units: Hyundai and Kia recalled 2016–2018 Ioniq and Niro hybrids and plug-in hybrids because the main relay that connects the high-voltage battery could come loose, overheat and, in the worst case, cause a fire.
- Critical severityFrequency: Occasional1.6 GDi híbrido (Kappa)Clutch hydraulic actuator (HCA): leak or moisture with risk of short circuit and fireYes, this is the most documented hybrid system fault: the hydraulic actuator that engages the combustion engine with the hybrid assembly has had two recalls (2018 for a leak on the Niro and 2025 for moisture in its electronic board on the Niro, Ceed and XCeed PHEV), with a risk of short circuit and fire.
- 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.
- 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.
Control units and comfort electronics (BSI, SAM...): the most serious faults by engine and car
- High severityFrequency: CommonPeugeot 408Electronic faults with the doors, boot and screen (suspected BSI control unit)In 2025 Peugeot recalled around 60,000 2023-2024 Peugeot 308 and 408 cars (code MUV) over a software fault in the door control unit that can cause unintended opening or closing and disable the anti-trap protection on the windows; 408 owners also describe a power boot lid that will not open or close and a screen that goes black.
- High severityFrequency: CommonRenault Laguna IIMultiplex electrical system and hands-free card faultsThe Laguna II had a reputation problem because of faults in its multiplexed electrical network: the hands-free card, the card reader and the ABS, ESP and handbrake warning lights came on erratically, especially in the early years of production (2001-2003).
- Critical severityFrequency: OccasionalMazda MX-5 IVDC/DC converter control unit fault with risk of short circuit and fireA 2018 Safety Gate alert covers MX-5 ND models built between August 2014 and April 2017: the DC converter control unit could fail, cause a short circuit and damage the converter, with a risk of fire. It is a precautionary recall; check the chassis number at the official service centre.
- Medium severityFrequency: Very frequentFiat StiloElectrical and electronic faults in the multiplex systemThe Stilo has had a reputation for widespread electrical faults since its launch: poor contacts in the multiplex wiring, an instrument cluster that switches off and sensors that disconnect, sometimes while the car is running.
Frequently asked questions
What does code P0045 mean?
That the ECU has detected an open circuit or an electrical fault in the solenoid that controls turbo boost pressure.[1][2]
Does P0045 mean the turbo is broken?
No. It points to the electrical circuit of the control valve: wiring, connector, the valve itself or the ECU.[1][2]
Can I drive with P0045?
Normally yes, with reduced power and gently to the garage, but do not put off the diagnosis.[1][2]
Will I pass the MOT with code P0045?
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.[3]
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.
- P0045 – Turbo/super charger boost control solenoid – circuit openTroubleCodes.net · Technical documentation · consulted 29 October 2026
- P0045 Code Symptoms, Causes, Diagnosis & Repair GuideFlagship One (FS1 Inc.) · Technical documentation · consulted 29 October 2026
- 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