A flat or disconnected battery often causes the Nissan Qashqai to no longer recognise the key and refuse to start. This problem occurs mainly with models up to 2016. It is usually solved by charging or replacing the battery. Want to know how to tackle this yourself and what the underlying causes are?
The Nissan Qashqai is known as a reliable family car. Even so, owners of older models regularly suffer from annoying starting problems. In most cases, the combination of a weak battery and key recognition is the main culprit. The battery voltage drops too low. The electrical system can then no longer recognise the key. The car will not start.
These Nissan Qashqai problems occur mainly after a period of standing still or in cold temperatures. The car does not respond to keyless entry. The starter light flashes. You see an error message on the display. Fortunately, in many cases these problems can be solved without expensive trips to the garage.
Why doesn’t the Qashqai recognise your key?
Key recognition in the Nissan Qashqai works via an electronic system. This system needs a constant power supply. The battery voltage drops below 12 volts. The system can then freeze. The immobiliser system interprets the low voltage as a security risk. That is why it blocks the engine from starting.
This problem occurs more often in models built before 2016. These are fitted with older battery systems. Older battery systems are more sensitive to voltage fluctuations. Owners report that the car can already show problems after standing still for just a weekend. This applies especially in winter. The battery in the key itself can also run flat. In that case, usually only the keyless entry stops working.
Common symptoms of battery problems
Recognise any of these signs? Then everything points to a battery issue:
- The dashboard lighting is dim or flickering
- The engine cranks slowly or makes clicking sounds when starting
- The red battery warning light is illuminated on the dashboard
- The car displays a warning about the Auto Start-Stop function
- The keyless entry no longer works
- You see an error message such as “key not detected”
These symptoms point to a voltage problem in the battery. The voltage is too low for the electronic system. Test the battery with a multimeter. That is a measuring device used to check voltage. At rest you should measure at least 12 volts. With the engine running you should measure around 14 volts. Lower values indicate problems. In that case you need to charge or replace the battery.
The battery as the main cause of starting problems
Research shows that battery problems are the cause of around 80 percent of starting issues. With the Qashqai this problem is even more important. The battery control module – the electronics that monitor the battery – is very sensitive to drops in voltage. As the battery weakens, the system automatically switches off certain functions. It does this to save energy.
Cold temperatures speed up this process. A battery may still perform acceptably in summer. In freezing conditions it can suddenly fail. The chemical reaction in the battery slows down in cold weather. As a result, less current is available. Long periods of inactivity make this effect worse. Even when parked, the car still uses power. For example, for the alarm system and onboard electronics.
A good battery delivers at least 460 cold cranking amps. That is the starting capacity at freezing temperatures. If this value is lower, replacement is sensible. If you replace the battery yourself, you will pay from about 45 euros. At a garage you will quickly pay between 300 and 500 euros.
How do you reset key recognition?
The battery has been charged or replaced. Yet the system may still be stuck. A reset of the key recognition usually solves this. This restores the problem of the key not being recognised. Follow these steps:
- Hold the key against the start button and wait a few seconds
- Press the brake and try to start again
- Disconnect the negative terminal of the battery, wait 10 minutes and reconnect it
- Use the emergency unlocking method via the keyhole in the driver’s door
If this doesn’t help, a deeper reset via the diagnostics system may be necessary. That is the built-in computer system that reads the car’s data. Some owners report success by switching the ignition on and off several times. Try not to start the car while doing this. This gives the system the chance to reset itself.
‘ That prevents the battery from running flat time and again. ’
Other causes of starting problems
The battery is the most common culprit. But other components can also cause problems. The starter motor can fail due to wear. You recognise this by clicking sounds from the relay. The engine does not fire. You can test this by gently tapping the starter motor with a hammer while trying to start. Does the engine respond? Then the starter motor needs to be replaced.
On diesel versions, air in the fuel line can occur. This happens mainly after refuelling. The engine turns over, but it does not start. Solve this by operating the fuel pump manually. Another option is to try starting several times in a row. A clogged fuel filter can make this problem worse. Leaking injectors can also aggravate the issue.
The alternator also plays a role. This component charges the battery while driving. Frayed wires in the voltage regulator interrupt the charging process. As a result, the battery runs down while driving. Check the wiring on the alternator for damage. Replacing a faulty regulator is relatively inexpensive. That prevents the battery from running flat time and again.
Problems with the Auto Start-Stop function
The Qashqai’s Auto Start-Stop function is directly linked to the battery sensor. That is the electronics that monitor the condition of the battery. If the voltage is too low, the system switches itself off automatically. At the same time it gives a warning. This is frustrating, but it is a safety measure. It prevents you ending up with a flat battery after several start-stop cycles.
There are other causes for this function failing. An engine that is too cold can cause it to be disabled. Overheating is another cause. Faults in the throttle sensor – the sensor that measures accelerator pedal movement – can also cause it to shut down. The system is designed to work only under optimal conditions. That means: at the right temperature and without faults in the system. Want to restore the function? First solve the battery problem. The warning often disappears by itself, usually after a few trips.
Practical tips to prevent problems
Regular maintenance prevents most starting problems. Think of checking the battery, replacing it in time and driving enough to keep it charged. Check the battery every six months with a multimeter. You can also have this done during the MOT. Replace the battery preventively after five years. This is especially important if you often make short trips. Short journeys mean the alternator does not have enough time to fully charge the battery.
Does your car often stand still? Then start it at least once a week. Then drive for at least 20 minutes. This keeps the battery charged. It also helps prevent the electronics from freezing up. For long periods of inactivity you can connect a trickle charger. That is a device that charges the battery slowly. It keeps the battery topped up without overcharging it.
Keep an eye on the battery in the key. Many owners forget this small component. A flat battery in the key fob – the remote control of your car key – can cause the same symptoms. It can then look as if the car battery is flat. Replace the battery in the key once a year as a preventive measure. This avoids confusion and ensures the key always works. It costs just a few euros and saves a lot of frustration.
‘ Don’t rely on guesswork when you have persistent problems. ’
When should you go to the garage?
The battery has been replaced. The system has been reset. But the problems still persist? Then you need a professional diagnosis. An OBD scanner is useful in that case. That is a device that reads fault codes from the car’s computer system. It reads the error codes from the system and points directly to the problem.
Possible causes include a defective battery control module – the electronics that monitor and manage the battery. Another cause can be a fault in the immobiliser. That is the security system that blocks the engine when it detects an unknown key. Electrical connections can also show signs of corrosion. Don’t rely on guesswork when you have persistent problems. Have the car tested by a specialist. A good garage uses professional equipment to check the electrical system. This enables technicians to pinpoint exactly where the fault lies. Look for a specialist with experience of Nissan models. The Qashqai’s electronic system requires specific knowledge.
Improvements in newer models
Nissan has acknowledged the battery problems. Since 2016 the brand has used improved batteries in the Qashqai. These have a higher capacity and perform better at low temperatures. The battery control module has also been modified. The aim: to react less sensitively to small voltage fluctuations.
Owners of newer models report fewer problems with key recognition. Starting is also more reliable. The keyless entry works more consistently. The system recovers more quickly after a charge with a booster pack. That is an external starter battery you can use to start the car when the main battery is flat. Even so, regular battery maintenance remains important, regardless of the year of manufacture.
Want to know more about common problems with your car? On the Carnews website you’ll find extensive information. There you can read maintenance tips and experiences from other owners. You’ll find practical solutions to technical challenges. Discover what other car enthusiasts share about their experiences and get the most out of your car.
Frequently asked questions
Common causes include a weak or flat battery, wear or defects in the starter motor and problems in the fuel system, such as air in the line or a clogged filter. Faults in the alternator or other electrical components can also lead to starting problems, for example because the battery is not charging properly. Key recognition issues are often related to a flat or weak key battery or a voltage that is too low in the vehicle’s electrical system, meaning the keyless or immobiliser system does not (properly) recognise the key. As a result, the Qashqai may not unlock or may not start, even if the engine is mechanically sound.
Start by checking the battery in the key (key fob): if the car no longer responds to remote locking/unlocking, replace the button cell battery first. Then try to start the car with the spare key to rule out a fault in just your everyday key. Hold the key as close as possible to the start button or the specified transponder area in the car; if it does respond then, this often points to a weak signal or low battery in the key. Finally, check for error messages on the dashboard (for example “Key not recognised”) and note them down for any follow-up diagnostics at the garage.
First check the battery in the key and replace it if necessary; a weak battery is a very common cause. Try the spare key to rule out a defect in the original key. Hold the key directly against the start button or another emergency start position specified by Nissan in the car, because in that case the car will sometimes still read the transponder. Make sure the car’s main battery has sufficient voltage, as an (almost) flat battery can also disrupt key recognition.
The NATS system (Nissan Anti Theft System) acts as an immobiliser that checks whether the transponder code read from the key matches the codes stored in the ECU. When you turn the key or press the start button, a coil around the ignition barrel or in the keyless module reads the key, sends the code to the NATS module/ECU and compares it with the authorised keys. Only if the code is valid are the fuel supply and ignition enabled and the engine can start; with an invalid or unrecognised key the starting system remains blocked. Faults in NATS (for example, voltage that is too low in the vehicle’s electrical system or a flat key battery) can cause the Qashqai not to recognise the key and not to start.
Yes, you can partly prevent key recognition issues by replacing the battery in the key in good time and always keeping a spare key in good condition. Make sure the car’s main battery is healthy, as low system voltage can also cause faults in keyless and immobiliser systems. Avoid exposing the key to moisture, drops or extreme heat for long periods, and do not store it directly next to strong magnets or electronic devices. If problems keep recurring, have the car checked, so that early faults in the keyless module or wiring can be detected at an early stage.
