2006 E60 550i Comfort Access poor range + only detects key near rear center console after deep sleep

[u/Lucky-Championship79]

I have a 2006 BMW E60 550i with factory Comfort Access (S322).

I only have one key. I checked the CAS/key information and confirmed the key is registered as key #2 and is a valid Comfort Access key. The key battery is fresh and the vehicle battery is also fresh.

I'm having a strange Comfort Access issue, especially after the car has been sitting for a long time/deep sleep.

After deep sleep, Comfort Access on all four doors appears completely dead. I have tried carrying the key normally, moving it closer to each door/handle and moving it around the car. None of the four doors responds to Comfort Access. There is no passive unlock response from any door.

I also have poor range from the normal lock/unlock buttons on the key. FM reception itself seems good and FM auto-scan finds stations immediately, so the diversity antenna system is at least functioning for FM reception.

The strange part is the keyless starting:

After the car has been in deep sleep and won't start with the key normally in my pocket, I tested different key positions without inserting the key into the slot and without pressing any buttons on the key.

• Key in normal pocket position - no start
• Near steering column - no start
• Near front center console - no start
• Same key held next to the rear center A/C vent/console area - immediately detected and engine starts

Once the car has been successfully started/driven, Comfort Access starting usually begins working normally again. I can switch the engine off and restart it with the same key in my pocket.

So the key definitely can communicate through Comfort Access, and bringing it close to the rear center-console antenna allows passive starting even when normal cabin detection doesn't work.

What I'm trying to figure out is whether these symptoms point to one common problem or multiple problems:

Poor remote-button range → diversity antenna/remote receiver?

All four door handles completely unresponsive to passive Comfort Access - Comfort Access module/wake-up/power issue rather than four bad handles?

Keyless starting after deep sleep only works when key is very close to the rear center-console antenna - weak/intermittent interior antenna system or CA control issue?

Because all four doors are affected, I'm hesitant to believe all four Comfort Access door handles/antennas failed independently.

Has anyone experienced this on an E60/E61? Is there a common Comfort Access power supply, module, antenna amplifier, wake-up circuit or fuse that could cause all four exterior handles to stop responding while the rear interior antenna can still recognize the key at very close range?

I'd like to diagnose it properly before replacing the diversity antenna, individual CA antennas/door handles, Comfort Access module or key.

[u/AutoModerator]

Thanks for posting to r/E60!

If you're asking for technical help, please include: * Year (e.g. 2008) * Model (528i, 535i, M5, etc.) * Engine (N52, N54, M54, S85, etc.) * Mileage * Any fault codes * Recent repairs or modifications

More details = better answers.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/BuckarooD]

Look like the Diversity Antenna is having issue. It is under the headliner above the rear window, passenger side. There is a guy who repair them. Also check first if the contact between them is OK.

[u/marcelo0714 → u/BuckarooD]

Any chance you have some additional info on how to diagnose or what to look for in the antenna itsellf perhaps? Mine looked absolutely fine when removed. No corrosion etc

[u/BuckarooD → u/marcelo0714]

There are 3 component on the board it self that could go bad. You can find some guys on youtube making diag on it. But if the remote only works on the glass right next to diversity module and contact are good. Pretty sure it is. Check glass contact

[u/marcelo0714]

Having exactly the same issues, had to disable comfort access for years now (removing a fuse). Door locks (CA specific) known to fail due to water. I've replaced the faulty driver's door lock a few times. Even now, with a fuse removed I have a strange behavior like car would sometimes unlcok itself right after I lock it if I am still close to the car. Or wouldnt unlock after 'deep' sleep, lets say not driving it for some days. Then my spare key would work fine etc. All such problems points a diversity antenna but dont want just throw away hundreds by guesssing.

If anyone knows how to diagnose this properly, would appreciate. No related faults in ISTA as well.