Car sometimes does not unlock from fob and does not start

biomecanoid

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This may be way off but, some cars will refuse to start if the vehicle was locked with a fob and unlocked with key. I found a rebuild kit for the FOB for the 2005 Buick Century online. My 2 cents
Oh that's weird now
 

biomecanoid

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Update

Yesterday I cleaned the battery poles and connectors with a bit of sandpaper. Tested the car late at night and it worked fine and today morning when going to work it started OK.

Seems it needed some cleaning even thought the battery and connectors did not look dirty or corroded. It could be a coincidence because the issue is known to come and go, so I will monitor the problem and let you know if it comes back.
 

Astro14

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The battery posts are not the only connection points that can corrode and cause problems.

Battery hot connection to starter. Battery hot to wiring harness. Battery negative to frame. Frame to engine block ground straps. May be a couple of those.

Pull, check and clean each of those.

You’ve checked two (of a dozen) spots where corrosion can cause increased resistance, by checking the terminals.

Time to follow where the electrons flow, and make sure that corrosion, age, etc. hasn’t caused a problem.

Corroded or broken ground straps from frame to block are a common problem in 15+ year old cars.
 

biomecanoid

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The battery posts are not the only connection points that can corrode and cause problems.

Battery hot connection to starter. Battery hot to wiring harness. Battery negative to frame. Frame to engine block ground straps. May be a couple of those.

Pull, check and clean each of those.

You’ve checked two (of a dozen) spots where corrosion can cause increased resistance, by checking the terminals.

Time to follow where the electrons flow, and make sure that corrosion, age, etc. hasn’t caused a problem.

Corroded or broken ground straps from frame to block are a common problem in 15+ year old cars.

Yes I should check all of the them
 
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Hello,

Some times going to the car after being parked (even not for long), it does not unlock using the fob, you have to use the key and when you use the key only the door you stick the key in unlocks while usually all doors unlock automatically. When you get into the car and turn the ignition car starts normally. This happens like 2-3 times a years so I did not bother with it because if I take it to the mechanic everything would appear to be normal.



Now yesterday and today the same thing happened but the car would not start, you would turn the key and the car would appear dead no sign of life, the dash would not light. To start it you have to turn the key keep it turned for like 10 secs and the car starts. This is a new behavior that just started yesterday this made me wonder so I decided to post here.



Battery and alternator are new and I have also tested them with a battery tester and everything seems OK. Is it immobilizer related ? What could the problem be ? if you want further details let me know.



When this happens radio stations are lost, clock resets, OBDII also resets.

My car is a 2006 Daihatsu Sirion
Yeah, Id replae the battery in the FOB and see if that helps. My wife's Hyundai did the same thing recently and replacing the FOB battery fixed it.
 

biomecanoid

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Yeah, Id replae the battery in the FOB and see if that helps. My wife's Hyundai did the same thing recently and replacing the FOB battery fixed it.
Initially I bought the car used and it came without a FOB. I used the car for about a year without a FOB. Then around the 2nd year I found a used original FOB for about 30-40$ paired it with the car and been working since.

How can a possibly bad battery on the FOB make the car have no electrical power ? no lights on the dash, no radio, no headlights etc and reset the Radio Stations, Clock and OBDII ?
 
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If the battery power is disconnected for a period, then the radio presets are lost, clock reset and normally the fuel mapping is also set to default.

From your first description, it sounds like you have intermittent battery disconnection. And most propably a loose connection somewhere.

Have you checked the fuses the holder and the wiring to them corrosion, loose fitting?
 

biomecanoid

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If the battery power is disconnected for a period, then the radio presets are lost, clock reset and normally the fuel mapping is also set to default.

From your first description, it sounds like you have intermittent battery disconnection. And most propably a loose connection somewhere.

Have you checked the fuses the holder and the wiring to them corrosion, loose fitting?
Yes I have checked the fuse box under the bonnet for obvious issues, moisture, corrosion etc. I have also cleaned with sandpaper the battery poles and connectors. Since I cleaned and tighten down the cables to the battery everything work fine.

I will also disconnect, clean and reconnect any other ground cables I can easily reach probably during the weekend. As far as I remember there are 2 ground cables coming from the battery
 

biomecanoid

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biomecanoid

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Well I did a quick search and found the products attached. I think the most relevant product is WD-40 SPECIALIST CONTACT CLEANER
 

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Dielectric grease, or regular grease. The object here is to keep any stray acid from corroding the metal.

Make sure the terminals are all the way down on the posts, almost touching the top of the battery. There should be some battery post showing above the top of the terminal. If necessary, loosen the bolt fully and spread the metal apart some so you can push the terminal all the way down before tightening the bolt.
 

biomecanoid

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Dielectric grease, or regular grease. The object here is to keep any stray acid from corroding the metal.

Make sure the terminals are all the way down on the posts, almost touching the top of the battery. There should be some battery post showing above the top of the terminal. If necessary, loosen the bolt fully and spread the metal apart some so you can push the terminal all the way down before tightening the bolt.
Nice tip, mine are no as you describe. I will fix them this weekend. I do have regular grease so I can use that, but that will not attract dirt and debris ?
 
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See if you can find some of what is called cosmoline in the US. It is a spray product used to protect machinery from rusting during storage. The army uses it on guns. It has a drying effect so it doesn't stay real sticky like grease would.
 
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Well I did a quick search and found the products attached. I think the most relevant product is WD-40 SPECIALIST CONTACT CLEANER
This may work to clean them but won't do much for protection, then again most people probably don't use anything and have no issues.
Nice tip, mine are no as you describe. I will fix them this weekend. I do have regular grease so I can use that, but that will not attract dirt and debris ?
If that is all you have I would use it but I would check an auto parts store and ask them if they have any battery terminal protection spray, I would find it unusual if they didn't have any. I've been using it for a long time and never have any connection issues with my batteries.
 

biomecanoid

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So will this do ? :

1631208596533.jpg
 
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