Quick answer:
- Press the brake firmly and fully — a partial press will not do it.
- A weak fob battery is the most common cause, and cold makes it worse.
- Almost every keyless car has a backup start method. Learn yours before you need it.
The Quick Checks
In order, and most people find their answer in the first two:
- Press the brake firmly and fully. The system needs a definite press; resting your foot is not enough.
- Confirm the transmission is fully in Park. Almost in Park will refuse. Try Neutral as well.
- Try the spare fob. If that works, your primary fob battery is flat — the most common cause by a wide margin.
- Hold the fob against the start button. Most cars have a backup inductive reader for exactly this.
- Move the fob away from your phone — other electronics can interfere with detection.
- Check for a low-fob-battery warning on the dash. Many cars warn for weeks first.
Why Winter Makes This Worse
Two of the common causes get considerably more likely once temperatures drop, which is why these calls cluster in the cold months.
Fob batteries are small coin cells, and cold reduces their output just as it does a car battery. A fob that was marginal in October stops working reliably in January — often intermittently at first, which is genuinely confusing until you connect it to the temperature.
More importantly, keyless systems are sensitive to low voltage in the car’s main 12-volt battery. The electronic modules need stable voltage to complete their checks and authorise starting. A battery weakened by cold may still light the dashboard while having too little left to satisfy those modules — which presents as an unresponsive button rather than obvious cranking trouble. People diagnose a “broken start button” when the real answer is a tired battery.
The Backup Method Everyone Forgets
Nearly every push-to-start vehicle has a documented way to start with a dead fob, and almost nobody knows theirs until they need it — typically in the dark, in the cold.
The most common method is holding the fob physically against the start button, or a marked spot on the steering column, so an inductive reader can detect the transponder without needing fob battery power. Some cars have a slot for the fob. Some need a specific brake-and-hold sequence.
Your owner’s manual has it. Spend two minutes finding it now. And locate the mechanical key blade hidden inside the fob while you are at it — if the main battery is completely flat, the doors may not unlock electronically at all, and there is usually a physical keyhole on the driver’s door behind a small cover.
When It Is Not the Fob
If the spare fob also fails, the fault is in the car rather than the key. The usual suspects are the same as any no-start: a discharged 12-volt battery, salt-corroded terminals, or a starting-system fault.
In this region terminal corrosion deserves particular suspicion, because winter road spray builds it steadily and it adds exactly the kind of resistance that leaves electronic modules short of stable voltage.
Button unresponsive and the spare fob no better? Call (412) 332-9926. That points at the vehicle rather than the key, and we test the battery, terminals, and starting system where the car sits.
Frequently Asked Questions
Why will my car not respond to the start button?
Most often a flat fob battery or the brake pedal not pressed firmly enough. Try the spare fob first — if it works, you have your answer.
Why does this happen more in winter?
Cold reduces the output of the fob's coin cell and of the car's main battery. Keyless systems need stable voltage to authorise starting, so a cold-weakened battery can present as an unresponsive button rather than slow cranking.
How do I start it with a dead fob?
Most vehicles let you hold the fob against the start button or a marked point on the steering column, where an inductive reader picks up the transponder. Your owner's manual gives the exact method.
The spare fob does not work either. What now?
That points at the vehicle — commonly a discharged 12-volt battery, corroded terminals, or a starting-system fault. Worth testing rather than guessing.
Can I get into the car if the battery is completely flat?
Usually via the mechanical key blade hidden in the fob, using a keyhole on the driver's door that is often behind a small cover. Worth locating before you need it.
Need a mobile mechanic in Pittsburgh? Call Pittsburgh Auto Repair Pros at (412) 332-9926 for fast, local, upfront-priced on-site service — or request service online. We come to you across the Pittsburgh metro.