Alright, here's the situation - I have a 2008 TL with Navigation... On Sunday, I decide that I'll try the baking method to see if it will "temporarily fix" my HFL module (unfortunately, it didn't work).

That brings me to the point ---The next morning, none of the following functions worked: memory seats, key fob/security/door locking, bright lights, turn signals, windshield wipers (except on high), and Navigation. The hazard flashers DO work though.

So, as any reasonable human would do, I go about checking all the fuses in BOTH the under hood and interior fuse blocks. No blown fuses found. Next, I go to the forums for insight... From what I could tell, I was having an issue with the MICU, which is integrated into the interior fuse block. After doing a little research, I decide I should seek professional help and took it into the dealer. 5 hours and $125 later, they tell me that they've isolated the issue to the MICU and I'll need to replace it/interior fuse block... OK - I'll buy that diagnosis. So, I buy the part at a reasonable $70 and install it tonight (after disconnecting the negative lead on the battery). Guess what - no dice!! Replacing the interior fuse block/MICU did not solve any is my issues.

Does anyone have any other wisdom to impart on this subject? What else do all of those functions have in common?

I plan to take it by the dealer again tomorrow and leave it with them, in the hopes they figure out what's wrong with it.

In advance, thank you very much for any guidance or advice!

-John

 

So you baked the HFL and the morning thereafter none of the posted components worked?

 

Right, I removed the HFL module, baked it, reinstalled it, and, the next morning, I noticed the problems. So, I'm thinking my mistake was in not disconnecting the battery prior to removing the HFL. After removing the HFL and before reinstallation, I did disconnect the battery...

 

Quick update - just heard back from the dealer and, apparently, the overhead interior light plug was actually plugged into a service port and they disconnected the (malfunctioning) HFL module. After doing so, all the errors seem to resolve themselves. I'm going to pick the TL up in just a few minutes and we'll see if everything is indeed corrected.

 

Didn't think that was humanly possible given the length of the harnesses...but there's a first for everything. Hope it works out.

 

Clarkbmw, I have the exact same problem you just described. So it was just the HFL module?