I have been having problems with remote keyless entry on my 99 Expedition for some time (entry using the keychain transmitter, not the keypad - that works fine). From reviewing some online articles and comparing to my symptoms it seems to be a receiver problem, so this needs replacement. My questions are two:
1. I am a bit confused about which module actually contains the receiver - I have found the module above the parking brake pedal which I have seen referred to by a couple of names including "RAP", and which is marked "Keyless / Anti Thft. The dealer has given me a part no. (1L3Z15607AA) which I have seen called variously "VATS", "PATS" and "TRCVR ANTI THFT". Are these the same module? Does this control all the keyless entry functions as well as the PATS key functions? (To add to my confusion the part no. on the module in my car does not match the number above).
2. Is this module a replacement I can do myself or would it be a dealer job for reprogramming of some form? If this same module deals with the PATSkeys then I certainly don't want to lock myself out of the car.
Any info or help most gratefully received.

 

Have you changed the battery in the key fob ?

 

I have changed batteries in both FOBs with same result. The FOBs can be re-programmed and will operate the locks most of the time if they are held underneath the steering column in close proximity to the RAP module, but will not work once the range is increase by even a couple of feet.

 

Why not take the opportunity to upgrade the unit. Just leave the original one where it is (RIP) and add an aftermarket unit. For $300 and 3 hours of work, I have a remote starter, keyless entry, and alarm. Once you have a 2-way remote, you'll never go back. It confirms back to you that the doors have locked or the car has started - whatever. And the range is much, much better than original.

 

Antennae is internal to the RAP module and must be replaced as a unit. Prior to removal of the RAP module, it is necessary to upload the module configuration information to New Generation STAR (NGS) Tester. This information needs to be downloaded into the new module once installed. For additional information; refer to Section 418-01 .
Newly released modules will require configuration after being installed. All configurable modules will be packaged in a kit which contains a warning label and a sheet re-emphasizing the requirements to configure replacement modules.

NOTE: The powertrain control module (PCM) has to be flash programmed using a flash cable.
Sounds like a dealer job, or else what heterodox1 said.