Electronic faults are not always complex, and are often caused by a weak battery, a poor earth connection or a corroded plug. Problems with the key losing synchronisation (where the car no longer recognises the signal), a jammed steering lock and a non-responsive remote control occur particularly often with the Dacia Logan MCV. These issues sound serious, but are often easy to fix. Read on to discover how to tackle electronic problems step by step.
What are electronic faults in your car?
Electronic faults occur when components or systems in your car no longer communicate properly with each other. This can be due to voltage problems, a blown fuse, a poor connection or a sensor that is no longer measuring reliably. These faults can show up in different ways.
Examples of common electronic faults include:
- Starting problems due to a flat battery or defective alternator
- Central locking cutting out or windows that no longer respond
- Warning lights on the dashboard staying on without a clear cause
- Lights that flicker or sometimes don’t work
- A steering lock that remains jammed after starting
Many of these problems are caused by a single underlying voltage issue rather than several separate faults. That makes a systematic approach valuable.
Why won’t the remote unlock?
A remote control that no longer responds is a very common complaint. This can be caused by a flat battery in the key, but also by desynchronisation between the key and the car. When desynchronised, the car no longer recognises the key’s signal.
Possible causes include:
- A flat battery in the remote control
- The key has been pressed several times while out of range of the car
- A fault in the central locking system due to voltage problems
- A weak battery in the car itself
The solution often starts with replacing the battery in the key. If that doesn’t help, you need to resynchronise the key with the car. You do this by turning the key in the ignition, locking and unlocking a number of times according to the procedure in the manual, and then starting the car. In many cases this solves the problem immediately.
Steering lock jammed after starting
A steering lock that won’t release is a common symptom of electronic faults. This happens when the electronic steering lock is not getting enough voltage, or when the sensor that monitors the key position is not working properly. The result is that you can’t turn the key, or the steering remains locked.
This problem occurs more often with:
- A weak or almost flat battery
- Cold weather, where the engine and electronics respond more slowly
- The car standing still for a long period
First try moving the steering wheel gently from side to side while turning the key. This relieves the mechanical load on the lock and can help release the blockage. If that doesn’t work, check the battery voltage. A battery with less than 12 volts when the engine is off delivers too little power for the electronic steering lock. Charge the battery or replace it if necessary.
Common causes of electronic problems
Electronic faults often have one or more common underlying causes. By checking things systematically, you can find the problem more quickly and avoid unnecessary repair costs.
Common causes include:
- A weak or defective battery that does not supply enough voltage
- Corrosion on terminals, earth points or plugs
- Blown or corroded fuses
- Poor contacts in plug connections due to moisture or age
- A defective alternator that does not charge the battery sufficiently
- Aftermarket accessories such as alarm systems or audio equipment that draw off voltage
Always start by checking the battery and charging voltage. Measure the voltage with a multimeter: a healthy battery supplies at least 12.4 volts with the engine off and 13.8 to 14.4 volts while driving. If the voltage is lower, check the alternator and the battery connections.
Inspecting earth connections and plugs
A poor earth connection is a very common cause of intermittent faults. The earth provides the electrical return path to the battery. If this connection comes loose, oxidises or corrodes, voltage problems arise that can show up in several systems.
Check the following points:
- The earth cable between the battery and the bodywork
- Earth connections at the engine and chassis
- Visible plugs behind light units, in the doors and around the fuse box
- Signs of moisture in the footwell or boot
Clean connections with a wire brush and make sure they are firmly tightened. Do not use WD-40 or other oil-based products on electrical contacts; instead, choose a contact spray that is suitable for electronics.
Diagnosing with an OBD2 scanner
Modern cars store fault codes as soon as a sensor or system is not functioning correctly. Using an OBD2 scanner, you can read out these codes without having to remove components straight away. This saves time and money.
An OBD2 scanner gives insight into:
- Engine management faults such as defective sensors or ignition problems
- ABS and ESP faults
- Airbag and seat belt pretensioner faults
- Problems with exhaust after-treatment
Connect the scanner to the OBD2 port, usually under the dashboard on the driver’s side. Read out the codes and write them down. Then search online for the meaning of the code and possible solutions. Note: a fault code often points to a symptom, not always directly to the root cause.
Preventive maintenance to avoid faults
Many electronic faults can be prevented with simple, regular maintenance. By paying attention to the battery, wiring and plugs, you keep the electronics reliable.
Practical maintenance tips include:
- Have the battery tested before winter, especially if it is older than four years
- Keep terminals clean and make sure they are firmly tightened
- Check earth points for corrosion and clean them if necessary
- Inspect plugs and wiring around the engine and in the doors
- Avoid long periods of inactivity; start the car regularly and take it for a drive
- Watch out for moisture in the car and investigate the cause if there are leaks
Also keep an eye on aftermarket installations. A poorly installed radio, dashcam or alarm system can draw power or cause faults in other systems. Check that these devices are connected correctly and that the wiring does not show any signs of short circuits.
When should you go to the garage?
You won’t be able to fix every electronic fault yourself. Sometimes professional diagnostics are needed to find more complex problems. Go to a garage if:
- Fault codes keep coming back after being cleared
- Several systems fail at the same time without an obvious cause
- You still have starting problems after replacing the battery
- There are safety-critical faults such as ABS, ESP or airbag issues
- The fault is intermittent and you cannot reproduce it yourself
A garage has access to advanced diagnostic systems and experience with specific models. They can trace communication errors between modules and carry out software updates where necessary.
Practical checklist for electronic faults
Use this checklist to work through things systematically before you go to the garage:
- Measure the battery voltage with the engine off and while driving
- Check all fuses and replace any that have blown
- Inspect terminals and earth connections for corrosion
- Check visible plugs and wiring for damage
- Read out fault codes with an OBD2 scanner
- Test whether the fault occurs under specific conditions such as rain or cold
- Check whether aftermarket equipment might be causing the fault
Write down when the fault occurs. Does it happen on a cold start, after rain, at idle or only while driving? This information helps to identify the cause.
Want to know more about car problems and maintenance?
On the Carnews website you’ll find extensive information about common car problems, maintenance tips and technical explanations for various makes and models. Discover more articles on electronics, engine, suspension and comfort to keep your car running smoothly and reliably.
Frequently asked questions
You often notice an electronic fault from unexplained or persistently illuminated warning lights on the dashboard, flickering lights or accessories (such as windows, radio, central locking) and sometimes slow or difficult starting. Also pay attention to symptoms that appear only occasionally, such as flickering lights or faults that disappear after switching the ignition off and on again. If several systems start behaving strangely at the same time, this can point to voltage or earth problems (battery, alternator, earth connections) rather than a single faulty component. Having fault codes read out early with an OBD2 scanner prevents small electronic issues from developing into major faults.
Common electronic faults that you can often diagnose yourself, and sometimes fix, include problems with the battery and charging voltage (starting issues, flickering lights), blown fuses or faulty relays, and poor earth connections or corroded plugs. Faults in lighting, windows, central locking and interior or dashboard lighting are also often easy to check yourself by inspecting fuses, bulbs and visible wiring. With a basic OBD2 scanner you can read standard fault codes from the engine management and, in part, ABS/airbag systems to make an initial diagnosis. You can also track down moisture or corrosion problems around fuse boxes, in the boot and under the bonnet yourself and often have them cleaned before they cause more serious damage.
The main causes of electronic faults are voltage issues (weak or worn-out battery, poor charging voltage), poor earth connections and corroded fuses, relays and plug connections, often made worse by moisture and corrosion. Poorly installed or messy aftermarket accessories can also cause faults in several systems at once. Prevent problems by having the battery and charging voltage tested regularly, keeping earth points and terminals clean and tight, and visually inspecting fuses and plugs for oxidation and damage. Also watch out for moisture inside the car and, in the case of unexplained faults, have the fault codes read with an OBD2 scanner before you start replacing parts.
Electronic faults can affect crucial systems such as engine management, ABS, ESP and power steering, causing the car to react unpredictably. When driving sportily, where you are closer to the limit, any hesitation in throttle response, braking power or stability control becomes extra dangerous. A weak battery or earth problem can, for example, lead to sensors dropping out or sending incorrect signals, which can cause unexpected intervention by driver aids or, conversely, their failure. That is why, if you drive sportily, it is essential to fix all electronic faults first (fault codes, earth points, battery, fuses).
The OBD-II system is the standard diagnostic interface in modern cars that lets you read electronic faults from, among other things, the engine and emissions systems via a connector and diagnostic device. The onboard computer stores faults as ‘Diagnostic Trouble Codes’ (DTCs), which in a fixed code format (for example P0300) indicate in which system and of what type the fault is. These fault codes are the starting point for diagnosis: they point you in a direction (for example ignition, fuel, sensor) but do not automatically tell you exactly which component is defective. After reading them out, the codes are interpreted and linked to measurements and symptoms to find the actual cause.