Hello, my key fob stopped working some time ago, I am quite certain it was after I installed the amplifier. I tried changing the battery on the remote, but without any results. I can lock/unlock only the drivers door only with the key itself (not the remote), the alarm does not go off either. I can fully lock everything from the inside tho. Note that the key fob does not react to the car no matter which button is pressed.
After I took out the car battery for recharging and installing it again there was a message on the dash display saying alarm service required, although it disappeared. Any ideas?

 

I've heard of others that bothered the car's main brain while fooling with the audio, especially if the battery wasn't disconnected. I've tempted fate myself.

If you had two key fobs, you could confirm that it was the car, not the fob. (As you probably know, it takes a dealer and at least $250 to set up a second key.)

A reading using the DiCE / VIDA system will tell you what is wrong. You can either take it to a Volvo-specialist indie, a dealer, or use a Chinese Clone DiCE unit of your own. If it takes reprogramming, you'll have to go to one of the first two.

 

The remote does not work the doors or alarm. Will it start the car?

 

Volvo has FOUR (count'em, four!) overlapping locking systems for its "conventional" ignition setups:

• The remote fob: This communicates with a small transceiver on the top of the DIM, which forwards the signal to the CEM for a smooth lock-unlock experience for body locks, headlights, and interior lights. Failure modes include low fob battery, corroded fob parts, and/or defective car-mounted transceiver operation.
• The lock/unlock buttons on the doors: Their function is similar to the remote's, including the "roll all the windows down/up" function. This sends a command directly to the CEM to coordinate all these services.
• The blade key: This is the failsafe door opener. As a bonus, it always sets off the car alarm. (Personally, I figure that anyone using a KEY is authorized to open the door. I guess they do it differently in Sweden.)
• The RFID chip in the neck of the key fob. This is the actual ignition lock. It is somewhat more reliable than the key fob (judging by the number of forum posts). It works on a VERY short range sensor in the ignition switch itself.

A failure in one system will not affect the other systems.