My keyless entry just quit working recently. I've searched, but haven't found anything that's been a big help yet. So far I've:

1. Checked fuses under the dash and under the hood.

2. Replaced the battery in the remote.

3. Bought a new remote.

4. Tried programming with both remotes.

No luck. When I try to program, I get the blinkers to flash twice like they're supposed to after inserting/removing key. After turning the key to ACC and pressing the lock button on the remote, though, nothing happens.

If I've done everything correct so far, is there an easy way to tell for sure if a relay or the control box has gone bad (and also what they might cost)?

Thanks for the help.