Symptoms
- Siren and lights continue even after pressing the fob
- Alarm restarts after seeming to stop
- Doors lock and unlock but alarm keeps sounding
- Started after a dead battery or jump-start
Likely causes
- CommonFob signal not reaching the receiverA weak battery or standing too far away can prevent the disarm signal from registering.
- PossibleAlarm system confused by low voltageA recent jump-start or weak battery can leave the alarm module in an unstable state.
- PossibleStuck door, hood, or trunk switchA sensor stuck in the 'open' position keeps re-triggering the alarm even after disarming.
- Less commonFaulty alarm control moduleAn aging or damaged module can fail to receive or process the disarm command.
What to do
- Get within a few feet of the car and press unlock, then lock, then unlock again firmly on the fob.
- Insert the physical key into the driver's door lock (if available) and turn it to unlock manually, which disarms many systems.
- Start the car if possible; many alarms silence automatically once the ignition is on.
- If it keeps sounding, disconnect the negative battery terminal for about a minute to force a reset, then reconnect.
- After reconnecting the battery, some systems need the fob reprogrammed or a specific relearn sequence from the manual.
- If none of this works, or you can't access the battery, call roadside assistance or a mechanic rather than let it drain the battery.
Tools and parts
- Wrench for battery terminal (if resetting)
When to call a pro
If disconnecting the battery doesn't stop it or you're not comfortable working near the battery, have a mechanic or dealer handle it.
Safety
Use caution
Wear gloves when handling battery terminals and always disconnect the negative (-) terminal first to avoid sparks.