Fiat 1.4 T-Jet / MultiAir Turbo (familia FIRE 16v turbo)Intake
MultiAir (UniAir) electro-hydraulic unit failure on the 1.4 T-Jet
Why this rating?
Medium severity: It can leave you stranded or get worse if ignored, without destroying the engine.
Frequency common: It appears on the reliability pages of the Fiat 500X and, in more detail, the Alfa Romeo MiTo, where several owners describe MultiAir module failure between 12,000 and 110,000 km on the 135, 155 and 170 hp versions; one report describes the reliability of the MultiAir "before phase 2" as mediocre. There are no fleet-wide figures or manufacturer campaign, so we classify it as frequent rather than very frequent.[1][2]
Symptoms
- The engine warning light comes on when the ECU detects a misfire linked to valve control.[2]Engine warning light: other faults that cause it · Garage soon
- Jerking or rough running when the MultiAir unit does not control valve opening properly.[1]Jerking: other faults that cause it · Garage soon
- Occasional loss of power while the unit fails intermittently.[2]Less power: other faults that cause it · Monitor
Why it happens
The MultiAir unit opens the intake valves using the pressure of a hydraulic circuit fed by the engine's own oil; a fault in the solenoid valve that regulates that pressure, or degraded oil, causes misfires and turns on the engine light.[2]
If it is not repaired: Repeated misfires force the unit to be replaced; in the documented Alfa Romeo MiTo case, the dealer did not cover the replacement under warranty despite the car's low mileage.[1]
Affected cars and years
It only affects the series with MultiAir technology (from 2009-2010): the first T-Jet series without MultiAir does not have this unit.[3]
| Version | Years | Codes |
|---|---|---|
| 1.4 MultiAir Turbo (2009-2020) | 2009–2020 | 940A2000940C2000 |
Models fitted with the affected versions
Abarth
- Abarth 5002008–2016
- Abarth 5952016–2024
Alfa Romeo
- Alfa Romeo MiTo2008–2018
- Alfa Romeo Giulietta2010–2020
Fiat
- Fiat Punto III2007–2018
- Fiat 500X2014–2018
Jeep
- Jeep Renegade2014–2018
- Jeep Compass MP2017–2020
Lancia
- Lancia Delta III2010–2014
How much it costs to repair
Includes: Replacement of the complete MultiAir/UniAir unit or block.[1][2]
Figures come from owner reports in France (fiches-auto.fr); there is no source with prices from a Spanish workshop, so it is worth asking for a local quote.
Prices in Spain, including VAT. A workshop hour costs on average €38–66 at independent garages and €77–134 at dealerships in Spain, depending on the region and the brand. How we calculate costs
How to check for it before buying a used car
- Ask for a fault code reading before buying: an unexplained intermittent misfire may point to the MultiAir.
- Ask about the oil change history: oil that is out of specification speeds up wear on this unit, according to the reports we consulted.[2]
Parts needed
The part or kit that fixes this fault, according to the sources.
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. Affiliate links
How to prevent it
- Always use oil with the specification required by the manufacturer and do not stretch the change intervals.[2]
Recalls, campaigns and claims
As of 27 September 2026, we have no record of recalls, campaigns or extended manufacturer warranties for this fault. Check with an official dealer using the chassis (VIN) number: they will tell you whether the car has any outstanding campaign.
What owners say
Frequently asked questions
What is the MultiAir or UniAir unit?
It is the system that replaces the traditional mechanical actuation of the intake valves with electro-hydraulic control: a solenoid valve regulates the oil pressure that opens and closes the valves, which makes it possible to vary their timing and lift.[3]
How much does it cost to replace the MultiAir unit?
One Alfa Romeo MiTo report puts the cost at around €1,400 at a French dealer, with no warranty cover; there is no equivalent confirmed figure for Spanish workshops.[1]
Does it affect all versions of this engine?
Only those with MultiAir, that is, from 2009-2010; the first T-Jet series without MultiAir does not have this unit.[3]
What can you do now?
We will put you in touch with a partner only if you authorise it in the form.
Other 1.4 T-Jet faults
- High severityFrequency: CommonTurboPremature turbocharger failure or wearOn the Fiat 500X, Fiat Tipo, Jeep Renegade and Jeep Compass there are recurring reports of turbocharger failure, sometimes at very low mileage (from 15,000 km); the manufacturer has offered occasional goodwill discounts, but there is no official campaign.Repair: €1,100–€2,300Appears at around 15,000 km
- Medium severityFrequency: CommonLubricationHigh oil consumptionThe Fiat 500X, Fiat Tipo, Alfa Romeo MiTo and Giulietta have accumulated reports of above-normal oil consumption, in some cases up to 1 litre per 1,000 km; keep an eye on the level between services and do not wait for the warning light.Appears at around 60,000 km
- Medium severityFrequency: OccasionalIgnitionMisfires and ignition coil faultsOn the Alfa Romeo MiTo there are reports of misfires that owners attribute to the coils, spark plugs and the MultiAir itself all at once, with the engine light on; we do not find the same pattern with the same clarity on the other models with this engine.
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Sources
Every fact on this page links to its source. If you find an error, let us know.
- Alfa Romeo MiTo : fiabilité, pannes et rappelsFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
- Fiat 500X : les plus et les moinsFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
- MultiAirWikipedia (inglés) · Other source · consulted 27 September 2026