My keyless remote doesn't work anymore to open my car doors an to set alarm, while walking away to or from vehicle...bought new battery for remote an it still doesn work...have to lock an unlock by hand now. is alarm active when locked with hand?....are they very expensive?

To arm content theft alarm.
1. Open the door.
2. Lock the door with the power door lock switch or
the remote keyless entry transmitter. The
SECURITY light should flash.
3. Close all doors. The SECURITY light should go off
after approximately 30 seconds. The alarm is not
armed until the SECURITY light goes off.

If a locked door is opened without the key or the remote keyless entry transmitter, the alarm will go off. The headlamps and parking lamps will flash for two minutes, and the horn will sound for 30 seconds, then will turn off to save the battery power.

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20 out of 32 products in Alarms, Remote Car Starters, Keyless Entry & Locks ..... ofKeyless Entry & Car Alarms allow you to lock and unlock power door locks.
How to program your keyless entry keypad - Ford Ownerhttps://owner.ford.com/.../locks.../how-to-program...Ford Motor CompanyDiscover how to lock and unlock your doors and how to program memory settings that will adjust seats & mirrors for each driver.SecuriCode™ Keyless Entry Keypad - Ford Ownerowner.ford.com/.../locks.../securicode-keyless-entr...Ford Motor CompanyLearn how to set a 5 digit SecuriCode on the Ford keyless entry keypad. ... Sign out. Register/Sign In · Your Vehicle. Service & Maintenance. Service & .... vehicle's SecuriCode keypad to lock and unlock your doors without having to use a key. ... Thekeypad will go into an anti-scan mode if you enter the wrong code seven ...How Programming Your Keyless Entry Can Make ... - Ford Life

Sounds like the contacts in the buttons are not making contact.. you may want to try taking the remote apart and cleaning the contacts and seeing what happens. If the remote is truely dead you may need a new remote

check remote battery if that doesn't work could be a fuse blown, the accuators are bad but if its doing both doors unlikely theyd both go bad at same time however some vehicles will not work on either if one of the 2 is bad that's me assuming you have a 2 door vehicle. same for 4 door but rear may work as front doors wont or all 4 could not work depends on vehicle. If its not accuator you could have a problem witht he alarm brain and for that take it to a stereo shop they do alarms and most places will check it for $25

Testing would need to be done , scan tool hooked up checking DTC'S - diagnostic trouble codes . View data etc...
Keyless Entry System Description and Operation - Active
The keyless entry system is a vehicle entry device. The keyless entry system is used in conjunction with the door locks to unlock the vehicle. Keyless entry will lock/unlock a door or open the rear compartment lid when a corresponding button on the keyless entry transmitter is pressed. This is accomplished by the transmitter sending a radio frequency to the remote control door lock receiver (RCDLR). The RCDLR interprets the signal and activates the requested function via a serial data message. A low transmitter battery or radio frequency (RF) interference from aftermarket devices, such as 2-way radios, power inverters, computers, etc., may cause a system malfunction. High RF traffic areas, such as gas stations that use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction. Keyless entry allows you to operate the following features:
• Door lock/unlock
• Rear compartment lid release
• Illuminated entry lamps
• Panic alarm/Vehicle locator
• Remote vehicle start

Your best bet , take it to a qualified repair shop . Dealer

Your battery is probably dead in the vehicle and /or the fob. Just use the key.

Is this an issue with all 2008 HHR remotes??? Highly doubtful , probably the vehicles keyless entry system . Taking the vehicle to a qualified repair shop an having the keyless entry system checked for DTC'S - diagnostic trouble code's . Do you know what a DTC is ?
The keyless entry system is a vehicle entry device. The keyless entry system is used in conjunction with the body control module (BCM) to remotely activate certain vehicle features. Keyless entry will lock/unlock the doors, or release the rear compartment lid when a corresponding button on the keyless entry transmitter is pressed. This is accomplished by the transmitter sending a radio frequency to the remote control door lock receiver (RCDLR). The RCDLR interprets the signal and activates the requested function via a serial data message to the BCM. A low transmitter or vehicle battery or radio frequency (RF) interference from aftermarket devices, such as 2-way radios, power inverters, computers, etc., may cause a system malfunction. High RF traffic areas may also cause interference that could lead to a malfunction. Keyless entry allows you to operate the following components:
• Door locks
• Liftgate lock
• Remote rear doors (Panel only)
• Vehicle locator/panic alarm
• Illuminated entry lamps
• Remote vehicle start
The keyless entry system has the following components:
• Keyless entry transmitters
• Keyless entry antenna
• 2 Way Advanced Remote Start RCDLR
• BCM

Guessing will not fix this .

need to have keyless entery module replaced

should not be using fob buttons for entry or locking for emergency only .if keyless entry walk up to car with fob do not press any buttons see if door opens then walk away from car with fob about 20m then go back to car without fob and see if door locked if so all working fine .indicators will not flash if the above dont work take back to main dealer for diagnostics keys may need to be reprogrammed

that is incorrect the alarm is jsut like any other it should only sound if there is a problem, which in this case there is, whoever you bought the car from is lying to you, i would have to say that the contrl module for passive alarm is bad