Security system not responding to key fob signal input

anon,
not told what car maker , model or year it is. (fail)
nor if you have only 1 fob, not 2 fobs that is super wise to do.
as in KEY FOB
now a pure generic answer,
All doors locked, not and will not open, guess yes locked
so the KEYFOB battery coin cell is now dead, as all do at 5 to 7 year.
the glove box users guide tells you how to replace the keyfob battery.
https://fobbattery.com/

each maker of FOB has there own way to open the FOB
so do no wreck the FOB guessing, why not tell what car this is first. and above damage in a panic.

once the doors open , we then run into the cluster security lamp
if key on fails now say so and what the lamp does. security.
never have 1 key for 1 car, that invites, costly tow service and costly reset of security systems onboard

never have just 1. fob. or it can be painful.
lost key , bad keyfob. drowned. or crushed, or flushed.

The starter solenoid is energized by the CRANK RELAY located in the engine compartment fuse box.

Turning the key to the START position provides power to the CRANK RELAY and issues a start request to the Powertrain Control Module (PCM). The PCM inhibits the CRANK RELAY from energizing unless the transmission is in PARK or NEUTRAL.

You need to test both sides of the CRANK RELAY control (coil) input during failure. If no power, ignition switch related. If no ground, PCM is inhibiting crank.

Suggest you have ODBII history checked for module communication faults or other malfunctions.

Locate your second key fob -
Try using that key fob -

if it does not work, and you can verify the Batteries in both Fob's are good - it could be a couple different things.

1. your security system control box may be 'bad'.
2. their is a 'ring' around the key area that are notorious for going bad and preventing the car from starting - however...they don't prevent the key fob from remotely opening the door locks.
3. The power feeding the security system is interrupted (blown fuse, etc) -

I would do the following:

1. Check the second fob and see if it works - If it does you have a bad #1 key fob (or battery).
2. Check ALL of the fuses (in the dashboard Drivers side access panel) AND under hood - Check even those not labeled security - as there are often fuses that feed more than one item, but are only labeled for one item.
3. Try going inside the car, shut all the doors, and lock/unlock the car five or six times using the interior control - I believe this is supposed to reset the unit.
I could be wrong - you can look this up. It might be that you have to do this with the key fob but I can't recall.

Give those things a shot. Also, make 100% sure all of the doors, hood, trunk, etc are fully closed.

I'd just about bet you have a bad key fob - finding #2 is the key here.

Beyond that - it's probably a trip to the junkyard for a new security module and matching set of key fobs - But long before getting involved in that - I'd bet you have a bad key fob or blown fuse -

Security Modules and key fob's are not universally replaceable, are extremely difficult to work with (for those without VIDA [Volvo Diagnostic software] and programming capabilities) and have to be programmed to work with the control unit to which assigned.

Yes you need to have a dealer test the system for fault codes.

The lock an car symbol is for the anti-theft system ! By not turning off, do you mean you can't turn the key to the off position or you can turn the key to off but the car won't shut off ?
It sounds like you have a Power Mode Mismatch
The ignition switch is an input to the BCM - body control module an if something happens to the system , the BCM will keep the vehicle in the last known mode Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the power mode master (PMM) fail to send a power mode message. The fail-safe plan covers those modules, using exclusively serial data control of power mode, as well as those modules with discrete ignition signal inputs.
You could have an ignition switch problem or something wrong with the BCM .
Discrete Ignition Signals Those modules that have discrete ignition signal inputs, also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 volts, the modules will fail-safe to OFF-AWAKE. In this state, the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.
This is one you need to take to the dealer because they have a factory scan tool !

although you can open the door with a key ,unless the alarm system senses a fob key signal it will assume that the door is being opened illegally and will set of the alarm
keys can be cut for all cars requiring a key fob unit but the alarm is not cancelled and the engine will not start
you may have to get another key fob and have it programmed to the ECM system

Firstly you need a good fob not a used one from another car as it is programmed to your vehicle "once" and cannot be programed from another car,this is a security procedure set with a PIN # assigned to your VIN # obtained from your Chrysler dealer,other wise any one could program a fob to your vehicle and drive away.Usually if a wrong key is detected either it won't start or will start momentarily then die,security light will flash with wrong key (fob)signal depending on year.

I think you might even have your car battery checked as it is the heart of all activity. Batteries can build up overnight and react differently in heat.

Along that line is the transmitter for your key-less, the mate to your FOB which needs and uses radio signals to operate. The heat may have gotten to the part inside your car. Heat messes with electric components and may drop the strength of the signal. This is what it sounds like happens if the FOB needs to be over the hood of your car to operate. The car part of the system does not have a strong enough signal to respond to the FOB. Could be a gap in the antenna in the responder.

I doubt it, why? most late model key fobs are transponders that signal the security system you are the owner.

hi,when you remove the key from the ignition,does the little flap in the barrell flip down?.if not the key fob wont work.it thinks the key is still in the barrell.after a tiny bit of wd40 on the key it was ok.it pickled me head for ages.maybe its that. paul