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Electrics and electronics

Problems of the key and keyless start: symptoms, cost and affected models

We have documented 26 faults of the key and keyless start in 26 cars. The most important by severity and frequency: start button that does not return to its position on the 2013-2014 e-NV200 (Nissan NV200), central locking and immobiliser failure due to worn relays (BMW Serie 3 E46) and false ESP/airbag warning lights, a humidity-sensitive SAM module and EWS immobiliser faults (Mercedes-Benz Clase C W203).

Documented faults
26
3 of high or critical severity
Cars analysed
26
with at least one fault on this part
Affected models
26
car generations in our database
Garage repair
No data
No reliable published costs

How we work

How it works and why it fails

Key, remote and keyless start

The car key carries a transponder for the immobiliser and, on many models, a battery-powered remote to lock and unlock from a distance, or a keyless entry and start system. When it fails, the car may not unlock or start even though the mechanics are fine.

What to do

If the car does not recognise the key, first try the spare key and replace the remote's battery. If the fault persists, the problem may be in the antenna, the immobiliser or the control module: it needs a garage with diagnostic equipment, and sometimes new keys programmed.

General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.

Common symptoms

The symptoms that come up most often in the documented faults of the key and keyless start. Open each one to see what other faults cause it.

Problems of the key and keyless start by car

Faults documented on specific cars, which occur with any engine. From most to least important.

  1. 1High severityFrequency: OccasionalNissan NV200Start button that does not return to its position on the 2013-2014 e-NV200Yes: in 2015 a recall was notified to Safety Gate because the start button on e-NV200s produced in late 2013 and early 2014 could stay pressed without returning to its position; if the car was driven like that, the emergency stop function could switch off the engine.
  2. 2Medium severityFrequency: CommonBMW Serie 3 E46Central locking and immobiliser failure due to worn relaysThe central locking can become intermittent or stop responding to the remote, and the immobiliser can fail sporadically when starting; gebrauchtwagenberater.de attributes both faults to wear in the relays of the control modules, and fiches-auto.fr records numerous testimonies of unreliable locking.
  3. 3Medium severityFrequency: CommonMercedes-Benz Clase C W203False ESP/airbag warning lights, a humidity-sensitive SAM module and EWS immobiliser faultsIt is one of the areas with the most complaints on the W203: ESP, SRS or airbag warning lights that come on for no reason, temperamental central locking, SAM modules that age badly with damp and, in units built before the 2004 update, faults with the EWS immobiliser and the steering column switch.
  4. 4Medium severityFrequency: CommonSeat León IIIRecurring electronic faults: screen, remote key and warning lightsYes: the magazine MotorMundial documents electronic faults that keep recurring on the Leon III, both in and out of warranty, such as the touchscreen going black or restarting, Bluetooth dropouts, the right-hand mirror not tilting down when reversing and warning lights that come on for no apparent reason.
  5. 5Critical severityFrequency: RareToyota C-HR IThe immobiliser can switch from "Ready ON" to "Ready OFF" while the car is movingOn vehicles built between 2020 and 2023, a weak standard immobiliser design can let the car enter "Ready ON" mode without properly verifying the key and then switch to "Ready OFF" while driving, which can cause the hybrid system to shut down on the move. Toyota fixes it by inspecting the vehicle at an official service centre.
  6. 6Medium severityFrequency: OccasionalAudi Q7 4LElectronics faults: MMI, keyless entry and comfort systemsThe Q7 4L is linked to faults with the MMI (screen, sound, menus), keyless entry antennas in the door handles and other comfort modules, often tied to damp or a weak battery.
  7. 7Medium severityFrequency: OccasionalDS DS 4 IIDS Iris multimedia system and key BSRF module faultsThe DS Iris multimedia system and the key electronics are the most repeated items in DS 4 owner reports on fiches-auto.fr: screens that freeze or go black, radio and navigation that fail, and one case of a car that will not start because of the BSRF module. There is no recall or independent study.
  8. 8Medium severityFrequency: OccasionalLand Rover Range Rover IIIOnboard electronics faults: immobiliser, warning lights, GPS and camerasAccording to fiches-auto.fr, 24 testimonials cite serious electronic faults: a car that will not start because of the immobiliser, multiple warning lights on, GPS and camera that stop working or clocks that fail, often linked to a weak battery or corroded earths.
  9. 9Medium severityFrequency: OccasionalMazda 3 IIKey detection fault and loss of power in intense coldSome Mazda3 owners, especially of the 2.2 MZR-CD 190, document minor key detection faults when starting and a loss of power in intense cold; gebrauchtwagenberater.de independently confirms that the electronics have caused problems in some units of this generation.
  10. 10Medium severityFrequency: OccasionalMercedes-Benz CLK C208Electrical faults: window winders, electric seats, alternator, starter motor and immobiliserAuto Bild (2007) identifies the electrics as the weakest point of the CLK C208: immobilisers, alternators and starter motors fail, as do comfort features such as the electric windows and electric seats. AutoScout24 (2009) adds occasional lighting faults, including xenon headlights.
  11. 11Medium severityFrequency: OccasionalMercedes-Benz SLC R172Left door locks that stay locked after using the remote controlYes: a 2018 campaign affects Mercedes-Benz cars, SLC included, built between October 2017 and April 2018, whose left-hand side door could be permanently locked after locking or unlocking with the remote control, with no way to open it from outside or inside. The solution is to replace the locks.
  12. 12Medium severityFrequency: OccasionalNissan Juke IIHands-free key recognition failure that prevents startingYes: fiches-auto and several owner opinions describe faults in the hands-free key recognition system that prevent the engine from starting, normally caused by the module that picks up the key's signal.
  13. 13Medium severityFrequency: OccasionalŠkoda ElroqKeyless locking and foot-sensor tailgate faultsAbout 25 owners say the Elroq does not lock when walked away from, or that unlocking from the handle fails. The foot-sensor tailgate first would not open and, from software 5.6, opens by itself and has closed on people. Workshops often find no fault, and updates rarely help.
  14. 14High severityFrequency: RareToyota RAV4 VHybrid stalls while driving because of the RAV4's immobiliser (2019-2023)A 2024 campaign covers hybrid RAV4s (2019-2023) whose immobiliser could allow 'Ready ON' mode without recognising the key, and then switch the system off, even while driving.
  15. 15Medium severityFrequency: RareDacia Logan IIKey that sticks in the start position (1.5 dCi, Logan MCV 2017-2018)Safety Gate (4/2021, Dacia code 0DCB) records a January 2021 campaign for the Logan MCV 1.5 dCi built between September 2017 and October 2018: the key can become stuck in the start position and damage the starter motor, with a risk of fire.
  16. 16Medium severityFrequency: RareDacia Sandero ISeized ignition lock barrel and keySeveral Sandero I owners describe a seized ignition lock barrel at around 20,000 km: the key will not turn or will not release the steering column lock. It comes from fiches-auto.fr reports, with no official recall.
  17. 17Medium severityFrequency: RareHonda Civic IXFaulty clutch switch on keyless-start diesels (recall)Diesel Civics with keyless entry and a start button built between 27 October 2011 and 4 September 2012 could start without the clutch being pressed if the switch failed.
  18. 18Medium severityFrequency: RareJaguar E-PaceSmart key and comfort electronics faultsAccording to testimonials on fiches-auto.fr, some Jaguar E-Pace owners report electronics faults: smart key not recognised with the car not starting and windows that open by themselves, as well as slow screens.
  19. 19Medium severityFrequency: RareMercedes-Benz GLB X24712 V battery: key, starting and control unit faultsAccording to the fiches-auto.fr page, the GLB's 12 V battery causes key, starting and control unit faults; two GLB 200 d owner reports (one at 123,000 km, with an MRM box) document it. It is a pattern of owner reports with no associated campaign.
  20. 20Medium severityFrequency: RareRenault Twingo IImmobiliser fault on the Twingo IOver the years the Twingo I's immobiliser can stop working and the car will not start; the German source says a new unit costs at least around €1,000, and sometimes the culprit is the key.
  21. 21Low severityFrequency: OccasionalDS DS 5Door handle sensor and keyless entry failureThe DS5 page records keyless entry faults: door handle sensors failing one after another (150,000 km on a 2.0 HDi 163), automatic locking that fails randomly and one case of a key recognition module costing more than €300.
  22. 22Low severityFrequency: OccasionalMitsubishi Colt VIElectrical faults: bulbs, immobiliser and batteryThe Colt VI is cited for faulty bulbs, immobiliser faults and flat batteries, and the immobiliser was among the fault points in the 2010 ADAC statistics.
  23. 23Low severityFrequency: OccasionalRenault Laguna ICentral locking, door lock and remote control failureAccording to the owner reports collected by fiches-auto.fr, the central locking and door locks fail, the remote control stops working at around 130,000 km and the instrument cluster or ABS show intermittent faults. No official recall is on record.
  24. 24Low severityFrequency: OccasionalŠkoda Fabia IIIElectronics faults: climate control, keyless key and driver assistance sensorsThe testimonies cite faults in the climate control module (at 10,000 km), keyless key detection (at 20,000 km) and Front Assist, parking or GPS sensors. That is more than 7 cases out of 117 testimonies.
  25. 25Low severityFrequency: RareMercedes-Benz Clase B W247Erratic Keyless key recognition and central locking faultsAccording to the fiches-auto.fr entry, some owners of the 2019-onwards B-Class have random key recognition and erratic central locking, attributed to weak batteries or a faulty Keyless antenna. It is an isolated pattern, with no associated campaign.
  26. 26Low severityFrequency: RareNissan Note IIStart button that stays pressed in (2015 recall)A European campaign from July 2015 affected the 2013-2014 Note: the start button could stay pressed and not return to its position after the engine started.

Problems of the key and keyless start by make

Frequently asked questions

Which cars have problems of the key and keyless start?

Among those we have analysed: Nissan NV200 (start button that does not return to its position on the 2013-2014 e-NV200), BMW Serie 3 E46 (central locking and immobiliser failure due to worn relays), Mercedes-Benz Clase C W203 (false ESP/airbag warning lights, a humidity-sensitive SAM module and EWS immobiliser faults), Seat León III (recurring electronic faults: screen, remote key and warning lights), Toyota C-HR I (the immobiliser can switch from "Ready ON" to "Ready OFF" while the car is moving), Audi Q7 4L (electronics faults: MMI, keyless entry and comfort systems), DS DS 4 II (DS Iris multimedia system and key BSRF module faults) and Land Rover Range Rover III (onboard electronics faults: immobiliser, warning lights, GPS and cameras). In total, 26 cars with documented faults of the key and keyless start.

What symptoms does a fault of the key and keyless start cause?

The most frequently cited in the documented faults: intermittent electronic warnings or sensor faults, hard starting or engine will not start, electric windows or central locking not responding, screen or infotainment system freezes or restarts, key is stiff to turn or gets stuck in the ignition and immobiliser warning light (key or padlock) on.