Dead Key Fob: Why the Car Will Not Start or Shift

You press the button and nothing happens, or the dash reports that no key is detected. Before anyone calls for a truck, there are two workarounds built into almost every keyless vehicle. Centennial Towing would rather tell you about them than tow you at (970) 432-4480.

Cold is why it happens here

A coin cell in a fob loses meaningful capacity as it gets colder, and a battery that was marginal in October is inadequate on a January morning in Colorado. That is why these calls cluster on the first genuinely cold days.

The tell is a fob that works at short range but not from across a parking lot, or one that works when warm in your pocket and fails after the car has sat overnight. Neither is the car; both are the fob.

Hold the fob against the start button

Most keyless systems have a backup that uses a passive coil rather than the fob's radio. Holding the fob directly against the start button, or against a marked spot on the steering column, lets the car read the transponder without the battery.

Some vehicles instead have a slot in the center console, in the glove box or in the armrest where the fob is placed. Others require the fob held against a particular point on the steering column. The owner manual says which, and it is worth finding out before you need it rather than on a cold morning.

The procedure is usually to press the brake, hold the fob to the point, and press start. It works with a completely flat fob battery on most makes.

The other battery

If the car is entirely dead, with no dash lights and no interior lighting, the fob is not the problem. That is the vehicle's twelve volt battery, and no amount of holding the fob anywhere will help.

The distinguishing test is simple. Fob problem: the car has power, the dash lights up, it reports no key. Vehicle battery problem: nothing lights at all, or everything is dim and the doors will not unlock electrically.

For the second, there is a mechanical key hidden inside almost every fob, released by a small catch, and a keyhole on the driver's door often concealed behind a cap. Getting into the car is the first step regardless.

When it will not come out of park

Electronic shifters need power and a valid key present, and a car that cannot confirm either will hold the transmission in park. That matters for towing, because a vehicle in park with locked wheels cannot be pulled onto a deck without skates.

Nearly every vehicle has a manual shift release for exactly this situation. It is usually a small slot near the shifter, sometimes under a removable trim cap, and it is operated with a key or a screwdriver while the brake is pressed. The manual shows the location.

Tell the dispatcher whether the car will shift out of park. It is the single most useful thing you can say about a keyless vehicle that will not start, because it determines the equipment that leaves the yard.

Electronic parking brakes

The related complication. An electronic parking brake will not release without power, so a vehicle with a flat twelve volt battery may have all four wheels held even after the shifter is dealt with.

Jumping the twelve volt system usually resolves both problems at once, which is why a driver may try that first even when nobody expects the car to start. Restoring power lets the brake release and the shifter move, and then the car can be loaded normally.

Replacing the fob battery

It is a coin cell, usually a common type, and most fobs open with a coin or a small screwdriver along a seam. The battery type is printed on the cell itself and often in the manual.

Note the orientation before removing the old one, since fitting it upside down is the most common mistake. Carry a spare in the glove box if you live somewhere that gets properly cold, because a two dollar part is what stands between you and a call.

Some vehicles need a relearn procedure after a battery change and most do not. If the fob does not work immediately afterward, try the backup start method before assuming the fob has failed.

When it really is a tow

If the backup method does not start the car, if there is no power at all after a jump, or if the vehicle will not release from park with the manual override, then it needs to go somewhere.

Say on the phone that it is a keyless vehicle, whether it has power, whether it shifts out of park, and whether the electronic parking brake is holding. Those four facts decide whether a wheel lift is enough or whether the car has to be winched onto a deck on skates.