Turbo and forced inductionGeneric OBD-II codeUrgency: Garage soon

P0234 on Renault: causes and affected engines

P0234 means: turbocharger or supercharger "A": excessive boost pressure (overboost).^[1][2][3] Renault has 7 documented faults that can trigger it, across 7 engines, including 1.6 dCi, 1.9 dCi, 2.0 dCi and 1.0 TCe / SCe. Only a diagnosis can confirm the cause on your car.

Documented faults

that can trigger it

Engines

used by Renault, with at least one of them

Renault models

with at least one of these faults

Urgency

Garage soon

Reviewed on 2 October 20265 sources How we work

Documented faults in Renault engines that can trigger P0234

Grouped by engine or model, from most to least important. These are faults with the turbo: not all of them will necessarily set the code, and only a diagnosis confirms the cause on your car.

1.6 dCi

In Espace V, Kadjar, Mégane III, Mégane IV, Scénic III, Scénic IV and Talisman

- High severityFrequency: CommonTurboPremature turbocharger failure or breakageThe 1.6 dCi turbo fails fairly often, sometimes at low mileage: fiches-auto documents failures between 23,000 and 113,000 km in the Kadjar, Qashqai II, X-Trail III and Espace V, with loss of power and, in several cases, the manufacturer refusing to cover the cost out of warranty.Repair (garage): €3,000

1.9 dCi

In Espace IV, Laguna I, Laguna II, Mégane I, Mégane II, Scénic I and Scénic II

- High severityFrequency: CommonTurboPremature turbocharger wearThe turbo on the 1.9 dCi can start to fail around 150,000 km, especially on the 100 to 130 hp versions built between 2000 and 2005. Renault went as far as covering up to 80% of the cost of out-of-warranty repairs, with no official campaign.

2.0 dCi

In Espace IV, Koleos I, Laguna III, Mégane II and Mégane III

- High severityFrequency: CommonTurboPremature turbocharger failureThe 2.0 dCi turbo fails relatively often, sometimes at low mileage: the reliability sheets consulted document dozens of cases in the Espace IV, Koleos and Laguna III, with whistling, loss of power and, in several cases, bluish smoke before the final failure.

1.0 TCe / SCe

In Captur II and Clio V

- Medium severityFrequency: CommonTurboMetallic noise or vibration from the turbo wastegateThe 1.0 TCe/ECO-G can develop a metallic noise or vibration from the turbo wastegate valve, especially when cold. It is the fault that recurs most across several independent sources; in a minority of cases it ends in a turbo replacement.

1.3 TCe

In Arkana, Captur II, Clio V, Kadjar, Mégane IV and Scénic IV

- High severityFrequency: OccasionalTurboTurbo actuator (wastegate) faultOn 1.3 TCe/DIG-T engines built up to 19 June 2020, the clip that holds the turbo wastegate valve rod may be missing or come loose, causing a loss of power with the injection warning light on. If the rod is left with too much play, the whole turbo has to be replaced.Repair (garage): €400–€700

1.5 dCi

In Captur I, Clio II, Clio III, Clio IV, Fluence, Kadjar and 11 more models

- High severityFrequency: OccasionalTurboPremature turbo failure and intake hoses that come looseThe turbo on the 105 and 110 hp 1.5 dCi can fail early: Caradisiac documents it on the Clio III, Scénic III and Qashqai II, sometimes before 80,000 km. More common and cheaper is for a turbo intake hose to come loose or burst and the engine to lose power.

0.9 TCe

In Captur I, Clio IV and Twingo III

- High severityFrequency: RareTurboTurbocharger wear or failureThe 0.9 TCe's turbo can lose performance or fail, although the available statistics put it as an infrequent fault on this specific engine.

Common causes of P0234 on any make

From most to least likely, according to the sources.

1Stuck or faulty wastegate, which does not open to relieve the excess pressure.^[1][2][4]
2Faulty pressure control solenoid (the N75 on VAG cars) or wastegate actuator: if they stay in the maximum pressure position, the turbo keeps raising the pressure.^[1][2][3][4]
3Blocked, deformed, disconnected or leaking wastegate control hose or pipe, which prevents the pressure from being relieved in time.^[1][2][3]
4Bent or seized rod between the actuator and the wastegate.^[1][4]

What to check first

The first diagnostic steps, from the most likely and cheapest to check to the most expensive.

1Read the code with a diagnostic tool, check the freeze-frame data and also consider any other stored codes, for example P0299 or P2563.^[2][4]
2In the live data, compare the requested boost pressure with the actual pressure under load, and the pressure sensor reading with the MAP sensor and atmospheric pressure: if they do not agree with each other, the problem may be in the sensor and not the turbo.^[4][5]
3Visually check the turbo hoses and the wastegate control hose (blockages, cracks, deformation, badly fitted connections), as well as the intake and exhaust: damaged parts, loose clamps, leaks or blockages.^[1][2][3][5]

Full guide to P0234: symptoms, diagnosis and whether you can drive

Frequently asked questions

Which Renault engines have faults that can trigger P0234?

1.6 dCi (1 fault), 1.9 dCi (1 fault), 2.0 dCi (1 fault), 1.0 TCe / SCe (1 fault), 1.3 TCe (1 fault) and 1.5 dCi (1 fault). Each fault has its own page with the affected years and versions, the symptoms and the repair cost.

What does code P0234 mean on a Renault?

Turbocharger or supercharger "A": excessive boost pressure (overboost). The engine control unit has detected that the actual boost pressure is higher than the pressure it is requesting itself: the turbo is delivering more pressure than intended, which can damage the charging system and the engine itself. In Saab's manual for a turbocharged 2.0 petrol engine, the code is stored when the actual pressure exceeds the requested pressure by a calibrated margin for more than 1.5 seconds. It is a generic OBD-II code: it means the same on a Renault as on any other make.^[1][2][3][5]

Can I keep driving with P0234?

Garage soon. The sources advise against carrying on driving normally: excessive pressure can damage the engine, including the head gasket, and they recommend repairing it as soon as possible. Autodoc Club says continuing to drive is not recommended; a German workshop accepts driving to the workshop in limp mode, but not making long journeys.^[1][2][4]

Sources

Every fact on this page links to its source. If you find an error, let us know.

Código OBD2 P0234: causas, síntomas y cómo corregirloAutodoc Club · Technical documentation · consulted 2 October 2026 · in Spanish
OBD2 code P0234: causes, symptoms & how to fix itAutodoc Club · Technical documentation · consulted 2 October 2026
16618/P0234/000564: Boost Pressure Regulation: Limit Exceeded (Overboost Condition)Ross-Tech · Technical documentation · consulted 2 October 2026
P0234 Ladedruck zu hoch: Ursachen und DiagnoseKFZ Dietrich · Other source · published 15 May 2026 · consulted 2 October 2026 · in German
DTC P0234 or P0299 9-5 (9650) 2011Saab Workshop Information System (WIS Online) (copia del manual de taller de Saab) · Technical documentation · consulted 2 October 2026