Fellow TL brethren, I've got a really weird electrical issue that is about to drive me batsh*t! This has been going on for several months now, but up until this started, I've had no real issues with the car.


So here's what happens: I set my dash nighttime brightness (headlights on) for a little less than 1/2 bright and daytime (headlights off) one notch less than maximum. I usually reset the trip odometers A/B after gassing up.


So, I drive the car, arrive at destination and shut off ignition. Then, about 80% of the time when I put the key back in the ignition and turn it on, my dash brightness is reset to maximum for night/day and the A/B trip odometers are both reset to zero. Also, I usually set the center display to show the outside temp and that choice gets reset and the MID only shows trip A.


It's worth mentioning that not only do the trip meters get reset, but all stats in the "trip computer" get reset to zero as well (time, MPG, avg MPH, etc).


What's bizarre is that it doesn't do this every single time. There have been *rare* occasions where it will be ok for a day or so.


My battery tests good (plus I still get these resets even when actively charging) which seems to me, eliminates the battery as the potential sore spot.


I've got the service manual and I did a diagnostic test of the MICU. There were a handful of DTC's relating to loss of comms with XM and the power seat (which I presume were all old - probably from me disconnecting the battery at some point). I cleared the DTC's, cycled the ignition switch several times, replicated the reset issue then checked for any new DTC's and there was only one - complaining about the passenger side mirror position sensor.


I'm all stock except for LED turn signals (with modified relay to eliminate hyperflashing), LED interior lamps, LED's for license plate and an ATLP J-pipe.


Anybody got any ideas WTF is going on? It's really, REALLY annoying to have the dash go full bright at night and have to lower it every time I start the f'ing car.


Thanks in advance for any help on this!

 

Im having the same problem with my '08 Tl-s which has been happening since a week ago. Does the below freezing temperatures cause this? Thanks in advance!

 

Using the same keys?
If so, I would next check the fuses that store the memory features. It's 1 or 2 fuses and I remember reading about those fuses when dealing with HFL issues.

 

Not sure if it's the same or related but I have an 08 TL Type S and occasionally have the Avg MPG and Avg MPH reset for no reason. I have not noticed the trip meters reset or the dashboard brightness change, but definitely do have the trip computer zero out and/or reset. There is seemingly no rhyme or reason to the frequency and as mentioned it happens occasionally.

I have only used one key fob and ambient temperature doesn't seem to be a causal factor. I do find it interesting that three of us are having somewhat similar symptoms and are all driving 08 TL Type S models. FWIW, I'm at 52.8K on the odometer.

 

I will check that out. I usually use key fob #1 but since the past week i had to use key #2 for a day. I'm not sure if that caused the problem or not. After that day i started to notice the navi would ask for the radio & navi codes. Today i drove to the store and started the car it asked for the navi code.

Another thing i noticed was when starting the car it would ask for the navi and radio codes. Then after putting in the codes it would have all the trip computers reset. I am going to try unplugging the battery for a night and see what happens. I have a little bit over 79k on my Type S.

 

Y'all need to check your battery and alternator condition using a multimeter.

 

I will check that out. I got a new battery just over a year ago. I'm starting that it has to be something with the alternator because before all this happened i disconnected the battery to Nokya yellow fog lights.

 

Set your dash brightness and trip display to your preference , I believe heat/cool settings too and try to set this for both Driver 1 and Driver 2 on the door panel. Oh an see if anything is blocking that half a sphere thingy close to the windshield the one that tells the nav system where the sun is.

 

Actually that sensor works along with the MICU and adjusts a couple settings.

 

This has been happening occasionally for years. By that I mean before and after battery replacement and although I haven't had the alternator tested, I bought my car as a CPO at less than two years old. While its possible, I don't think there is anything wrong with the alternator seeing other than this anomaly at seven years old it's is still charging my battery fine and have no other electrical issues.

If its asking for Radio and Nav codes, I suspect there is an issue with you battery. How old is it?

 

I got the battery a year ago. Would you think the HFL would be draining the battery causing it to ask for the Radio and Navi codes?

 

That's possible. The parasitic drain caused by faulty HFL has been well known to drain batteries.

This thread may be helpful - https://acurazine.com/forums/audio-b.../#post15334910

 

Thanks, I haven't had time to unplug the HFL at the moment, but this past couple of days the Avg trip computer reset about 4 times. It would ask me for the navi code which is really annoying. Hopefully disconnecting the HFL works

 

In addition to checking battery and alternator health, make sure to check your grounds. Bad grounds lead to very odd electrical issues as well.

 

I disconnected the HFL and cleaned the battery terminals and ground. If these don't fix the problem i will check the alternator health.