We're working on a fix — Diago should be back shortly. Thanks for your patience.
Diago
Instant AI vehicle diagnostics
Diago
Instant AI vehicle diagnostics
A car that won’t start can be anywhere from a $0 fix (loose battery terminal) to a $1,500 repair (fuel pump). What you hear — or don’t hear — when you turn the key is the first clue.
| Symptom | Most likely cause |
|---|---|
| Nothing at all | Dead battery, blown fuse, bad ignition switch, or security lockout |
| Single loud click | Bad starter motor or starter solenoid |
| Rapid clicking | Dead or nearly dead battery |
| Cranks but won’t fire | No fuel (pump, filter, or empty tank), no spark (ignition), or no compression |
| Cranks slowly, then starts | Weak battery or high resistance in battery cables |
| Starts then immediately dies | Failing immobilizer, bad idle air control valve, or fuel delivery issue |
The #1 cause. Batteries typically last 3–5 years. Cold weather accelerates failure. A quick jump or load test confirms it.
Starter motors wear out, especially over 100k miles. Usually a single loud click or grinding when you turn the key.
Engine cranks normally but won’t fire? You may not be getting fuel. Listen for a faint whine from the fuel tank when you turn the key to ON.
Modern cars won’t start if the key chip isn’t recognized. A dead key fob battery or damaged key can trigger this.
If the alternator doesn’t charge the battery, a healthy battery goes dead overnight. Car starts fine but dies after a jump.
Battery corrosion adds resistance and can prevent enough current from reaching the starter. Free to fix with a wire brush.
Describe exactly what happens when you try to start your car and Diago will narrow it down — likely cause, what to check first, repair steps, and local shop prices.
Diagnose why my car won’t start →Power to lights and accessories but no crank usually means a bad starter, starter relay, or security system issue — not the battery itself. Describe exactly what you see and hear in Diago for a more precise diagnosis.
One loud click = starter problem. Rapid clicking = dead or dying battery. Both are usually straightforward repairs once confirmed.
Yes. Most cars after 2000 have a chip in the key that the immobilizer reads. A dead battery in the fob, a damaged key, or a failed antenna ring can prevent the car from starting entirely.
Yes — Diago supports cars, trucks, vans, SUVs, motorcycles, semi trucks, RVs, buses, and more. Just pick your vehicle type when you start a diagnosis.