Starting, battery and electrics
Car will not start and does nothing or just clicks
If the engine does not even turn when you turn the key or press the button, or you only hear a click, power is not reaching the starter motor. The most common reasons are a flat battery or loose terminals; after that, the starter motor or a safety switch.
Check without hurryStarting, battery and electrics
Reviewed by Daniel Morales, founder of Reprorace SL, on
Is it serious? Can I keep driving?
Usually not urgent, but do not ignore it. There is no risk while the car is parked somewhere safe. If you jump-start it or use a booster, follow the order in the handbook; if the battery is swollen, smells bad or belongs to a hybrid, do not try and call for assistance.
A careful, general answer: only someone who inspects the car can say whether it is safe to drive. When in doubt, stop somewhere safe and call for assistance.
Most likely causes
- Flat or aging battery: the dashboard lights look weak or flicker when you try to start.
- Loose or corroded terminals: current does not flow even with a charged battery.
- Starter motor or its relay: a sharp click with a good battery usually points to the starter.
- Start safety: on automatics the lever must be in P or N; on manuals the clutch fully pressed.
- Immobilizer or control unit: some cars block starting if they do not recognize the key.
Listed from more to less common in general; on your car they may be different. A fault-code reading and a check at the garage confirm which one it is.
To understand it better: How can you tell if the 12 V battery is failing? What do U codes and lost communication (U0100) mean? Can you diagnose a hybrid or electric car with an OBD scanner?
Car system: Electrical system and battery
What you can check yourself
Switch on the headlights: if they look weak or die when you try to start, it is the battery.
Check the lever is in P or N, or the clutch is pressed all the way.
Make sure the terminals are tight and clean, with the car off.
If you jump-start it or use a booster, follow your car's handbook procedure.
Safe checks only: with the engine off and cold whenever you look under the hood, without taking anything apart and without touching hot or moving parts.
Related fault codes
- P0562System voltage: too low
- P0560System voltage: malfunction
- P0705Transmission range sensor A, circuit: PRNDL input
- P0706Transmission range sensor A, circuit: range/performance
Generic codes that often come with this symptom. Seeing one does not confirm the cause: it is where the diagnosis starts.
How the ECO-LITE helps diagnose it
Plugged into the OBD socket, the ECO-LITE reads the fault codes of the control units that answer, with the freeze-frame data captured when the fault happened, and shows live data on your phone or computer. With your permission, your garage can see them remotely before you bring the car in.
What to look at here: system voltage with the ignition on and during the start attempt; gear selector codes on automatics.
Frequently asked questions
How do I know if it is the battery or the starter?
If the lights dim a lot when you try to start, it is usually the battery. If the lights stay bright and you only hear a click, it points to the starter or its supply.
How long does a car battery last?
It depends on the climate, the use and the car; short trips and cold wear it out sooner. If it has gone flat several times, have it tested.
It started with jump leads. Is that it?
Not necessarily: if the battery went flat for no reason, there may be a drain while parked or a charging fault. Check before it happens again.
Keep reading
- Electrical system and battery: how it works and what fails
- Car battery keeps going flat: causes and what to do
- Engine cranks but will not start: causes and what to do
- Battery warning light on: what it means and what to do
- Car symptoms: what they mean and what to do
- Check engine light on: what to do
- How to read and clear your car's fault codes
- OBD fault codes: what each one means