Comfort Access Only Works On Hatch/Ignition (Not Doors)

[bquicksilver]

Any ideas what could be the cause?

- I've check every fuse listed with the *door* icon (in both boxes). All were fine. (27,28,30,124,132,135, 145-148). Are there other CA fuses?
- I've replaced the batteries with quality replacements in both FOB's.
- The behavior is consistent, not associated with rain/car washes, etc. It has this issue of only doors not working 100% of the time.

Other Possibly Relevant Info:
- No CA features work on the 2nd key FOB
- I replaced the driver door handle due to heat buildup. No longer hot, but still no CA function.
- Doors do not lock or unlock via CA. Pushing buttons fine on both key FOBs.

[ninja_zx11]

Try to scan with a bmw software.

[bquicksilver]

Any DIY thoughts or cases of a similar issue?

[heatmizr]

Remove mittens?

[bawareca]

Try disconnecting the battery overnight if you didnt already. Many times when new parts are replaced they need to be properly "introduced" and that happens on power-up. It is a rule in the VAG world.

[bquicksilver]

No luck disconnecting the battery.

Dealer suggested replacing every door handle "and wiring". Wasn't too impressed with their diagnostic. (thankfully they agreed and waived the fee) They did get both FOB's to work with the ignition and hatch.

Ideas?
Would one bad antenna disable every door?
Any idea how to ID a bad handle with it out of the door? (I'd pull them all if I knew how to test them)

[bawareca]

Why am I not surprised by the dealer's suggestion
It will be fuel for the infinite improbability drive if all 4 door handles went out of order at once and everything else is working fine. And you replaced the driver side with a newer, less used one. If it were me i would leave the handles alone and look at the control unit. I dont remember if your CA was working when your door handle was heating up, but it may have damaged the control unit, or it may need coding after replacing the handle. If you look at the CA document I posted in the other thread you will see that the 4 door handles communicate with the CA thru 1 line, and all other antennas (that work) are using different channel. The dealer tech probably checked the actual values and saw no communication with the door handles and decided they are all bad, but if it were me i would suspect the CA module.

[mega]

I hate bumping old threads, but I'm hoping you found what was wrong?

Ours just started doing this, doors do not lock/unlock but I dont have to put key in ignition.

not sure how to diagnose comfort access in ISTA/D it does not seem to have a function test for the door sensors

[bquicksilver]

Still no luck. I wish someone with more electrical knowledge than myself could suggest how to individually diagnose the handles. I don't mind having the dealer swap out control units and code, but them swapping out painted handles indiscriminately at ~$500+ea doesn't settle so well. I just wish I could diagnose those handles.

[swanpoint]

Same issue w/ 2011 X5, 35i. Started with drivers door; I didn't take the dealer's $650 offer to replace the actuator on the drivers door. Year later, the other 3 doors stopped working.


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