: Memory doesn't hold



Sinhue
11-21-08, 03:36 AM
Help. I just installed a double din touch screen stereo in my 1999 Eldorado, and now the memory settings don't stay, such as the trip meter, MPG, and
my presets on the stereo don't work either.
We have checked the wiring on the stereo and they all seem correct.
Any suggestions would be helpful..Thanks!

**I got the idea for the stereo from a pic in a post that I attached..
*****This is not my car****

CadillacSTS42005
11-21-08, 11:08 AM
please search
this problem has been beaten to death
there is no constant wire on the radio harness
you must run your own constant from the battery

Sinhue
11-22-08, 01:59 AM
I have searched and I have found your posts regarding the direct wire to the fuse, and/or to the battery, but does that also affect the memory settings in the car's computer such as MPG and Trip and all those settings ?

CadillacSTS42005
11-22-08, 10:23 AM
if you have the wrong adapter
aka the pos 20 dollar gm32b from metra instead of the gmos-03 which is required to maintain the data class signal
then yes
again this has been posted many times before

Sinhue
11-26-08, 01:58 AM
Well, I found the problem. The settings were resetting b/c the power line for the amp was occassionally twisting and causing some sort of
short, or it triggered some security feature that shut the electrical system down. I tightened that up so it didn't move, and spliced the constant 12 from the stereo into the amp power cable which works out well b/c it was pretty convenient to do..
Thanks for the help!

K_cin_az
12-26-08, 06:48 PM
Well, I found the problem. The settings were resetting b/c the power line for the amp was occassionally twisting and causing some sort of
short, or it triggered some security feature that shut the electrical system down. I tightened that up so it didn't move, and spliced the constant 12 from the stereo into the amp power cable which works out well b/c it was pretty convenient to do..
Thanks for the help!

Hello Sinhue,

This is exactly what is happening to me. I have a double din installed with the GRMC-03 and a constant run direct to the head unit. The same thing is happening where something is getting triggered messing with the car's trip settings and the key fob. The constant is spliced from the power wire running to the amp. So you found that the wire was simply "twisting and needing tighting?" Did this fix your problem. What did you do just eliminate any slack? Any more details you can provide would be great of how you fixed this problem.

(I also never jumped wires e6 and f6 *purple data class wires* together)

N*Caddy
12-27-08, 01:24 AM
Normally you don’t really need to jump the data wires together, but if you have a problem with the car data bus circuit in the same network loop where the radio use to be integrated (say MSM and/or SDM) you can get into some problems.
Possible problems:
- Air bag will not deploy in that exact moment when you need-it (let’s hope you won’t need-it to begin with)
- The memory seats will suddenly stop working.
Then other strange stuff (cascade effect) like BCM internal error. It happened to me the night I took the Radio and Climate Control Module out to change the lights with LEDs. The BCM “forgot” to turn off the headlights and guess who was jump starting the car next morning?
So again normally you don’t need to jump the wires; the car is designed to work with one missing device in each network loop but think to the unthinkable…

K_cin_az
12-27-08, 01:07 PM
thanks n* , I will jump the wires next time i get the head unit out to see if that helps anything out...i think you were right on the other post in the eldo thread that it more than likely the contstant from the aftermarket hu draining the battery to a point that it messes with the electronics. Seems kind of odd to me though that a constant would drain that battery that much., dont most headunits have a constant power source?

Sinhue did you ever get to the bottom of the problem? Were you able to get a constant run that didn't cause these problems anymore?

N*Caddy
12-27-08, 02:08 PM
I actually believe the problem was indeed an occasional short like Sinhue mentioned above. Come to think, if the continuous wire will slowly suck the life out of the battery you should see at least some of the following codes:
B0856 - Battery 2 Out of Range
B1981 - Battery Voltage Low
B1652 - Loss of Keep Alive Memory (KAM)
B1327 - Vehicle system voltage below 9.0 volts
None of the above codes (with the exception of KAM) will show for a short occasional voltage drop.
The strange part is the problem occurred only after prolong periods with the engine OFF. Normally if the car is OFF no bumps thus no reason for a wire to touch another one and cause a short.

K_cin_az
12-27-08, 02:18 PM
Yeah never have seen any of those codes pop up and as you mentioned only happens when the car has not been turned on for I would say over 10-15 hours or so....

N*Caddy
12-27-08, 02:36 PM
Seems kind of odd to me though that a constant would drain that battery that much., dont most headunits have a constant power source?

About that, most of the aftermarket units do have a constant wire because are not integrated in the car data system (generic use). So for example if the unit has a clock then you need power to run-it (not the case with the OEM units witch receive the time from the data bus). And is not only the clock that requires continuous power some temporary memories (like the RAM in your computer) also need power to be kept alive. The OEM units are designed with the full car electrical system in mind and to save power as much as is possible, off course price is a huge part in the equation (unfortunately). An aftermarket unit is designed mostly for look and perceived performance, but you do have to compromise few things (like the steering wheels controls, the chime and the driver settings plus possible network issues). So unless that unit is darm good in sound quality (i.e. pretty pricey) there is no reason to make these compromises. I wouldn’t. If all you need is to be louder (for some reason?!) you can always add amplifiers and just change the speakers. Keep in mind, if you do that, the control wire to power the amps is not the power antenna wire witch only works with the unit ON. The chime needs to work even with the HU OFF, so the remote wire for additional amps should be tapped on the power pin of the HU amplifier chip. It is a little off the topic, but is something to consider when you modify the sound system.

K_cin_az
12-27-08, 05:10 PM
well i put in a double din ipod/nav unit so it really wasnt about loudness other than putting a toy in there, its my fun car so wanted to put in a cool deck, didnt realize the havoc having a au in there would cause with the constant wire....

Sinhue
12-30-08, 04:03 AM
I fixed both problems: the stereo losing memory and the car DIC losing memory.

Stereo = Wire the aftermarkets HU memory directly to the battery (as STS300 has stated before.)
1. I tried wiring to the factory constant.. didn't work
2. I tried wiring directly to the fuse... didn't work.
Bypass factory constant..

DIC = wire e6 and f6 together. I have not lost memory settings since I did this. has been about a month..

K_cin_az
01-02-09, 06:26 PM
thanks, I will do the fuse of wire e6 and f6 together and maybe that will fix my problem. So do you think that is what fixed your problem and not a twisted wire?

I have the constant wired but like N* mentioned it seems to be drawing too much power as after about 8-10 hrs of sitting their it triggers the electrical system shut down where the DIC gets reset and it also turns off the key fob. Man that would be sweet if fusing the wires fixes the problems, will try it out shortly!