: 2005 STS Electric Issue



walshgrad54
11-08-12, 01:33 PM
I have 2005 STS with the 3.6 V6. About 30 days ago I came out in the morning and the doors wouldn't unlock and even after using the key to open the drivers door it wouldn't start. Upon using jumper cables it started right up. I immediately went to the parts store and had both the battery and charging system checked. I was supprised to find that both were fine. I actually had both the battery and charging system checked 2 more times over the next few weeks at different part stores and they continued to check out in good standing. Everything seemed to be just fine until this morning when I went to leave my home and once again the Fob was unresponsive and had to use drivers door key to get in. Once again no luck with the vehicle starting. It doesn't even give me the "no fobs detected" message which I've had before. Once I put a jump on it started right up and has turned on and off with no issues at all. I have no idea where to go from here please help!! Thanks in advance.

Also on a side note betweeen occurances I did replace the fob battery and it seems to work like a dream. I was having a problem with it not responding promptly, but that seems to be great now.

It seems like it must be an electrical issue either harness or connection, but I don't even know where to start.

I love my STS but this is getting old real quick! Thanks again as any advice is appreciated!

B1n2fra
11-08-12, 05:55 PM
Check the battery cables for loose connections. Start there...

EChas3
11-08-12, 10:15 PM
Have you ever had the issue with the other Fob?

sapien
11-09-12, 09:01 PM
how old is the car battery? it may seem to charge up fine but once it starts to go bad, you will have weird issues with the fob detection, auto unlock, etc.

when this happened to me awhile back the battery had gone dead a couple times, but would still charge up. a new (and better) battery cured it 100%

EChas3
11-09-12, 10:03 PM
Some free battery tests are not even worth the time spent. I'd expect at least 1 out of 3 to test it under load, but it could still be bad. A poor connection seems more likely to me.

Good luck.

ddalder
11-09-12, 10:53 PM
I question the ability of a parts store to properly test a battery and charging system. To properly test a battery, it must be fully charged first. Charging systems are much different now than years back. Charging systems are no long on or off. Charging is duty cycled in these cars from (as I recall) 5 - 95% depending on many factors. If a you have the battery properly checked and it is fine, you can also check all the connections (as mentioned). Failing this, I'd be off to a dealership or other reputable vendor who understands and can check modern automotive electrics.

Giddy
11-20-12, 06:43 AM
Did this every get resolved. My battery on my 2008 died on the weekend. We boosted it yesterday and it worked fine all day. (except the radio sounds which I posted elsewhere) We went to use it this morning and its the same thing. Doors won't open and nothing electrical works. This was a new battery about a year ago that was replaced under warranty.

Could it have failed already? Any other suggestions? The Fobs wouldn't cause this, would they?

Ludacrisvp
11-20-12, 08:38 AM
could be a defective battery ...
how are your battery cables looking? does your car have some kind of excessive parasitic electrical draw? Any aftermarket electronics?

Giddy
11-20-12, 10:34 AM
could be a defective battery ...
how are your battery cables looking? does your car have some kind of excessive parasitic electrical draw? Any aftermarket electronics?

Cables look good and the only aftermarket item in/on the car was my cell phone charger which I unplugged this morning just in case.

I boosted the car again and went for a drive with it and watch Voltage Meter go from the low 14's down to the high 13's which I thought was normal range. I was just about home and it suddenly was at about 13.0 and went as low a 12.8. I stayed driving for while longer and it stayed in the 13 range very steady. I brought the car home and let it idle in the driveway for about 20 minutes. I rechecked it and it was bang on 13.0. I have turned of the car now but will try again soon.

One other thing that I am not sure about. The Ultrasonic Rear Parking Assist lights were flashing on and off while driving this morning too. To be honest, I don't recall if the car has always done that. There is no warnings coming from the display saying I have any issues at all.

Giddy
11-20-12, 04:16 PM
Just an update if it matters. Been driving it off and on all day.

The car re-starts at about 13 battery volts, finds its way up to 14.1 volts and then steady declines to around 13.0 where it seems to stay for the rest of the drive.

The Parking Assist lights are working properly again too. Not on or blinking when in drive and do their job in reverse.

Does all this sound normal?

Thank you.

EChas3
11-20-12, 09:45 PM
It does sound like battery cable connections might be the root cause. Has it been garaged?

For the parking assist, clean & check the rear bumper sensors.

Giddy
11-21-12, 06:23 AM
It does sound like battery cable connections might be the root cause. Has it been garaged?

For the parking assist, clean & check the rear bumper sensors.

The battery connections look ok. No corrosion or anything that shouldn't be there. Should I loosen them and tighten them back up again or do something else to them. The car is a daily driver and out every day.

The parking assist seems ok now. This is what has me somewhat concerned. I had no radio sound after the first boost. The radio worked, but my parking assist was blinking after my second boost. All seems ok (touch wood) after several restarts now.

I do appreciate you help Echas3.

Giddy
11-26-12, 01:56 PM
Another update. My mechanic said I needed a new alternator because battery voltage while operating at around 13 battery volts is not good. They called to get a re-manufactured alternator and were told that I did not need one. The alternator re-builder said that the alternator is computer controlled toonly puts out as many volts as needed by the car at that time. It can even go below 12.6 and that's ok if the battery is not in need of recharging at that moment. So, it will go to the mid 14's (which it has on occasion since watching the gauge almost constantly now) and then find its way down to the low 13's or less until additional drain requires more voltage.

I do not think I have read the above anywhere on these forums and would appreciate feedback that anyone might have. I hope its correct and I will save my money.

GG

ddalder
11-26-12, 07:57 PM
Another update. My mechanic said I needed a new alternator because battery voltage while operating at around 13 battery volts is not good. They called to get a re-manufactured alternator and were told that I did not need one. The alternator re-builder said that the alternator is computer controlled toonly puts out as many volts as needed by the car at that time. It can even go below 12.6 and that's ok if the battery is not in need of recharging at that moment. So, it will go to the mid 14's (which it has on occasion since watching the gauge almost constantly now) and then find its way down to the low 13's or less until additional drain requires more voltage.

I do not think I have read the above anywhere on these forums and would appreciate feedback that anyone might have. I hope its correct and I will save my money.

GG
It sounds like your mechanic is not fully up to date on modern vehicles. Duty cycled charging systems have been around for many years now. In the STS, they will charge at anywhere from 5-95% duty cycle, depending on what the Instrument Panel Module determines the SOC or State of Charge to be. This is based on several factors including battery voltage, ambient air temperature and other criteria. The IPM will have the PCM control the field on the alternator accordingly. These systems are not all or nothing like they were many years back. This is why the shop is seeing a lower charge output than they may have expected.

Giddy
11-29-12, 01:51 PM
It sounds like your mechanic is not fully up to date on modern vehicles. Duty cycled charging systems have been around for many years now. In the STS, they will charge at anywhere from 5-95% duty cycle, depending on what the Instrument Panel Module determines the SOC or State of Charge to be. This is based on several factors including battery voltage, ambient air temperature and other criteria. The IPM will have the PCM control the field on the alternator accordingly. These systems are not all or nothing like they were many years back. This is why the shop is seeing a lower charge output than they may have expected.

Ok, not sure I understand everything that you posted. I agree that my mechanic was suggesting a new/rebuilt alternator. The place where he was going to get it from told him I likely don't need one because of it being computer controlled. At least both were honest and saved me some (probably a bunch) of money.

Ludacrisvp
11-29-12, 03:03 PM
Very true. I believe alternator is near bottom of engine therefore would be a few hours labor plus part cost that would likely be in the $400 - $500 range so you might be pushing $1k total.

Giddy
12-02-12, 06:07 AM
Very true. I believe alternator is near bottom of engine therefore would be a few hours labor plus part cost that would likely be in the $400 - $500 range so you might be pushing $1k total.

I was wondering where it is and if I could have done it myself. Just glad I didn't have to try. The car seems to be behaving and the battery volts fluctuate from mid 12's to mid 14's. I just have to make myself stop looking at the reading all the time now. I wonder why they have the volt meter in the car if the reading is meaningless???

DarkMingBlueSTS
12-02-12, 07:56 AM
When I first start mine it reads 14.4 then slowly drops in ".x" increments to 13.0. But that's after like 15 minutes of driving it. I'm assuming that's ok?

ddalder
12-02-12, 11:31 AM
... I wonder why they have the volt meter in the car if the reading is meaningless???
What do you mean by this? The volt meter isn't meaningless, it's in understanding how to interpret what you're seeing.

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If you look in the Owner's Manual, it states "The normal battery voltage range is 11.5 to 15.5 volts when the engine is running." When the battery voltage reaches an estimated 16 volts, an overcharge condition exists and the appropriate warning is displayed. The manual provides specific directions about what to do if this occurs. When the battery voltage is less than 10 volts, or the battery has been drained, a low voltage condition exists. Again, direction is provided about what you should do.

Giddy
12-02-12, 06:53 PM
What do you mean by this? The volt meter isn't meaningless, it's in understanding how to interpret what you're seeing.

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If you look in the Owner's Manual, it states "The normal battery voltage range is 11.5 to 15.5 volts when the engine is running." When the battery voltage reaches an estimated 16 volts, an overcharge condition exists and the appropriate warning is displayed. The manual provides specific directions about what to do if this occurs. When the battery voltage is less than 10 volts, or the battery has been drained, a low voltage condition exists. Again, direction is provided about what you should do.

What is this Owner's Manual that you talk about. :) Actually, thank you for pointing that out as I wanted to hear something along that line to put my mind at ease that the car is ok. Much appreciated.

ddalder
12-03-12, 01:16 AM
What is this Owner's Manual that you talk about. :) Actually, thank you for pointing that out as I wanted to hear something along that line to put my mind at ease that the car is ok. Much appreciated.
No problem. It's pretty dry reading, but it's surprising how much good information is there. I make a point of hunting down the manual for a car before I buy it. That way I know exactly what the features are and it helps me find one with the available options that I want. Sales staff deal with so many different cars that I find they truly don't know any of these cars in depth. This is especially true of pre-owned sales staff that deal with many makes, models and years.