PSA 1.4 TU3 and 1.6 TU5 (motores TU, 8v and 16v)Engine sensors
Sensors that fail: lambda sensor and temperature sensor on the 1.4 and 1.6 TU3/TU5
Why this rating?
Low severity: A nuisance or wear. It does not immobilise the car or damage other parts.
Frequency common: Along with the coils, it is the category with the most mentions in the Fiches-auto.fr compilations consulted: 64 sensor cases across the Peugeot 206's petrol engines combined and about 40 in the Citroën Xsara, plus repeated mentions in the 307, C2, C4, Xsara Picasso and Berlingo/Partner. These are figures from owners' reports, not a failure statistic per unit sold, but the repetition across so many different models supports the view that it is a common weak point of the engine.[1][2][3][4][5][6]
Symptoms
- The engine warning light comes on when the ECU detects an inconsistent reading from the lambda sensor or the temperature sensor.[2]Engine warning light: other faults that cause it · Garage soon
- An unstable idle and slightly higher fuel consumption are common when the lambda sensor or the temperature sensor sends an incorrect reading to the ECU.[4]Uses more fuel: other faults that cause it · Monitor
Why it happens
These sensors are exposed to the heat of the engine bay and, over the years, their connectors corrode or their internal element degrades; the lambda sensor, in addition, gets dirty from the passage of exhaust gases.[1]
If it is not repaired: The car can still be driven, but with an unstable idle, slightly higher fuel consumption and, if it is the lambda sensor that fails, a risk of damaging the catalytic converter in the long run because of an incorrect fuel mixture sustained over time.[4]
Affected cars and years
It affects the 8- and 16-valve versions equally: the lambda sensor and the temperature sensor are parts common to all of them.[1]
| Version | Years | Codes |
|---|---|---|
| TU3 1.4 75 hp 8v (TU3JP/TU3KFX, 1994-2014) | 1994–2014 | TU3JPTU3KFX |
| TU5 1.6 88-90 hp 8v (TU5JP, from 1994) | 1994–2005 | TU5JP |
| TU5 1.6 16v 109-112 hp (TU5JP4/TU5NFU, from 2000) | 1999–2010 | TU5JP4TU5NFU |
Models fitted with the affected versions
Citroën
- Citroën C22003–2009
- Citroën C3 I2002–2009
- Citroën Xsara1997–2006
- Citroën Xsara Picasso1999–2010
- Citroën C4 I2004–2008
- Citroën Berlingo I1996–2012
Peugeot
- Peugeot 2061998–2010
- Peugeot 2072006–2014
- Peugeot 3072001–2008
- Peugeot Partner I1996–2012
How much it costs to repair
Includes: Sensor (lambda sensor or coolant temperature sensor) and replacement labour, normally under an hour[3]
An owner of a Citroën Xsara Picasso cited a cost of around €20 for the temperature sensor, but it is a single report collected by Fiches-auto.fr and not a figure backed up by more quotes; we have not found any other references published in Spain to give a reliable range.
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 the codes to be read: a faulty lambda sensor or temperature sensor will usually leave a fault code stored even if the warning light is off at that moment.
Parts needed
The part or kit that fixes this fault, according to the sources.
- Buy part at Autodoc (affiliate link, opens in a new tab)
Lambda sensor
Measures the oxygen in the exhaust gases so that the ECU can adjust the fuel mixture.
- Buy part at Autodoc (affiliate link, opens in a new tab)
Coolant temperature sensor
Tells the ECU the engine temperature so it can adjust injection and switch on the cooling fan.
Affiliate links to Autodoc: if you buy, MotorFiable may receive a commission at no cost to you. Check compatibility using the registration number or the VIN before ordering. More information
How to prevent it
- Do not ignore an intermittent engine warning light even if the car seems fine to drive: a sensor that is starting to fail usually gives erratic readings before it breaks completely.
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 symptoms does a faulty temperature sensor cause?
Most commonly a cooling fan that comes on at the wrong time, an inconsistent temperature reading on the dashboard or the engine warning light coming on.[1]
And a faulty lambda sensor?
An unstable idle, slightly higher fuel consumption and the engine warning light on; over time, a faulty lambda sensor can also speed up wear on the catalytic converter.[4]
Is the repair expensive?
It usually isn't: these sensors are accessible and cheap compared with other engine parts, although we have not found a published average quote in Spain for this specific engine.[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 and 1.6 TU3/TU5 faults
- High severityOccasionalFrequency: OccasionalCylinder head and blockHead gasket damaged after overheatingThe head gasket fails mainly as a consequence of previous overheating -from a coolant leak or a faulty thermostat- and not as a factory defect: it appears in a minority of engines, almost always between 30,000 and 180,000 km, with coolant loss, emulsified oil or white smoke.Appears at around 30,000 km
- Medium severityCommonFrequency: CommonIgnitionIgnition coils that fail and cause jerkingThe ignition module -a rail with two twin coils, no distributor- is the electrical fault owners cite most across all models with this engine: it usually fails between 40,000 and 150,000 km and causes jerking, an unstable idle or the engine warning light coming on.Appears at around 40,000 km
- Medium severityOccasionalFrequency: OccasionalCoolingThermostat stuck open or closedThe thermostat -the controlled "calorstat" on the more recent versions- can stick: if it closes, the engine overheats; if it stays open, it is slow to reach temperature and uses more fuel. It is one of the cooling faults owners of these engines cite most.
- Low severityCommonFrequency: CommonLubricationOil leak from the rocker cover gasketThe rocker cover gasket dries out with the years and lets oil seep into the spark plug wells: besides the oil stain on the engine, it can soak the spark plugs or the ignition module and cause misfires.Appears at around 120,000 km
More faults with the engine sensors on other engines and cars
- High severityOccasionalFrequency: Occasional2.0 DTI and 2.2 DTIVP44 injection pump and air mass meter failureGerman Wikipedia documents recurring failures of the Bosch VP44 injection pump and the air mass meter in the early years of this engine. An owner testimony for this engine describes the pump being replaced at 192,500 km, at a cost the owner calls «prohibitive».
- Medium severityCommonFrequency: Common2.0 TDIClogged particulate filter or faulty pressure sensorThe 2.0 TDI's particulate filter clogs if the car mostly makes short journeys, because it never gets to regenerate; sometimes the fault is just the differential pressure sensor. Cleaning it costs around €200 and replacing it, €800 to €3,000.Repair (garage): €800–€3,000
- Medium severityCommonFrequency: Common1.4 and 1.6 8vCrankshaft position sensor failure (TDC sensor)The crankshaft position sensor (capteur PMH, or TDC sensor) appears repeatedly in the reliability sources for the Clio II, the Kangoo I and the Dacia Logan I with this engine, with hard cold starting or stalling as the main symptoms. It is a cheap part, but the failure can leave you stranded.
- Medium severityCommonFrequency: Common1.4 and 1.6 16vCrankshaft position sensor failureThe crankshaft position sensor (capteur PMH) appears repeatedly in the reliability sources for almost every generation with this engine, with hard cold starting, stalling or the car cutting out unexpectedly. It is a cheap part, but the failure can leave you stranded.
- Medium severityOccasionalFrequency: OccasionalBMW B57AdBlue/SCR system fault (NOx sensors, heater and pump)A specialist garage considers the B57's AdBlue/SCR system the fault that most often leaves cars immobilised: a NOx sensor, the quality sensor, the heater or the pump usually fails, and topping up the tank rarely stops the countdown of remaining starts.
- Medium severityOccasionalFrequency: Occasional1.2 8v FireSensor failures: lambda sensor and crankshaft position sensor (TDC)The 1.2 8v Fire can suffer sensor faults: the lambda sensor (warning light, rough running) and, in the Fiat Punto, the crankshaft position sensor (TDC sensor), linked to misfires. These are minority issues, but they recur across several models with this engine.
Have you had this fault? Your case helps other owners know when it appears and how much it costs. Report your fault in 2 minutes.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- 1.Tous les problèmes sur Peugeot 206 (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
- 2.Tous les problèmes sur Citroën Xsara (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
- 3.Tous les problèmes sur Citroën Xsara Picasso (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
- 4.Tous les problèmes sur Citroën C2 (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
- 5.Tous les problèmes sur Peugeot 307 (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
- 6.Tous les problèmes sur Citroën Berlingo (témoignages)Fiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French