[golfbrah]

Do I need to replace my fried CAS3 module with the exact same part number?

Or, can I simply purchase any CAS3 module and program it to work?

Thanks!

[gbalthrop]

1) WHAT symptoms, fault codes, or Scan Tool Error Message causes you to believe your CAS (Car Access System) Module is "fried"? Do you know which two fuses power that Module on your model, and have you tested them?

2) What are the Last-7 characters of your VIN? So we can lookup circuit/fuse information on your vehicle and provide you with CORRECT wiring diagrams & test procedures.

3) What Brand/Model Scan Tool or Diagnostic Software do you have? What Fault Codes are read in the CAS Module, or if your Software/ Scan Tool says "No Communication" with CAS, are you able to "See" or "Communicate" with all ~ 20 OTHER Modules in the Vehicle? What Error Message related to CAS do you see exactly?

4) If the CAS were totally inoperative, you could NOT:
1) Lock/ Unlock the car using a Remote Key;
2) Have Radio come on when Remote Key inserted in Insert Compartment;
3) Have Instrument Cluster light-up when you press START button WITHOUT pressing Brake/Clutch;
4) Have ANY accessory powered by 30G relay operate when START pressed.

How many of the above apply in your case?

I realize this does NOT answer your question, but your initial post offers NO suggestion that you have correctly diagnosed the issue. Also, the use of the word "fried", and interchanging "CAS" module (which ALL E9x vehicles have) with "Comfort Access" (option) raises doubts about the diagnosis.

With answers to those questions, we can help,
George

[golfbrah]

You're right, I wrongly assumed CAS3 = Comfort Access/Passive Go

My Passive Go module is fried. Neither of the door handles work and the engine won't start without a key inserted into the slot. Looks like this one is easy to replace...?

[gbalthrop]

Do you have TWO remotes or only ONE? If TWO, does ANY function of either work? Have you removed & tested Remote Battery voltage, or Replaced the Remote Battery?

Why do you believe something is "fried"? Connectors get corroded or knocked loose. Fuses fail.

Have you checked the fuse for CA? Depending upon the build month/year of your "tbd" (which you never told us ;-) the fuse is F19 (built BEFORE 3/1/2007), F33 (built 3/1/2007 - 8/31/2007), or F61 (2008 & later).

Was any repair or disassembly done in the console area (or elsewhere in the vehicle) prior to the remote NOT working as previously?

There are FOUR (4) Antennas in the system, PLUS the Antenna Diversity. If BOTH doors quit working at that same time, it is NOT at all likely that BOTH door handle units quit working at same time. See the attached ISTA ScreenPrints. Since I didn't know what vehicle you have, I used 2008 & later E90 Sedan. I would suggest using Multimeter to test for 12V+ at Pin #14, Red/Yellow wire, of Connector X13354 at the A215 Module with Ignition ON. ALSO check for Continuity to Chassis Ground at Pin #16, Brown wire, Connector X13354.

Loose or corroded connectors or wires are MUCH more common than faulty control module electronics.

George

[gbalthrop]

Attached as described in prior post.

George

[Andystobbs]

Can't those symptoms present when a door handle goes down and jams the TAG bus. I'd be unplugging door handles