Car sometimes does not unlock from fob and does not start

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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
 

biomecanoid

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Electronics today .... (n)
Does the Key Fob have its own battery ?

Mine does and I will be changing it 'before' it starts acting up.
It has a battery yes, but I don't think its the fob, because when this happen the car is DEAD, no electricity at all. Plus since yesterday it does not start. You have to keep it turning the ignition for about 10 seconds and the magically it starts
 

Astro14

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If the radio stations and other presets are lost, then you have a problem with the car’s primary battery voltage. You state that the battery is new, and the alternator is new.

But that battery is failing to provide proper voltage to the car, so it either has to have a bad connection to the car, or is poorly charged.

Go over your cables and connections, particularly ground connections.

And put a new battery in the fob, they’re what, $3? Eliminate that as a potential cause.
 

biomecanoid

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If the radio stations and other presets are lost, then you have a problem with the car’s primary battery voltage. You state that the battery is new, and the alternator is new.

But that battery is failing to provide proper voltage to the car, so it either has to have a bad connection to the car, or is poorly charged.

Go over your cables and connections, particularly ground connections.

And put a new battery in the fob, they’re what, $3? Eliminate that as a potential cause.
I have this TOPDON battery tester:


Checks battery, alternator and load tests. Everything checks out fine car battery health 100%, voltage and alternator is good.

I will get another battery its not a big deal, but the fob is independent and not part of the key, they are 2 pieces how could that made the car not start ?
 

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Complete electrical failure ? Nope , not the fob . But you'll probably get more people tell you to change the battery in it ...
 

Astro14

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Again, your battery may check out fine.

But the connection from the battery to the car is intermittent, or failing. So, you have resistance that causes a voltage drop.

The voltage drop causes the failures that you’re seeing, the no start condition, and the loss of radio stations.

You need to check the battery and cable connections.

You‘re looking for loose, broken, or corroded connections.
 

biomecanoid

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Again, your battery may check out fine.

But the connection from the battery to the car is intermittent, or failing. So, you have resistance that causes a voltage drop.

The voltage drop causes the failures that you’re seeing, the no start condition, and the loss of radio stations.

You need to check the battery and cable connections.

You‘re looking for loose, broken, or corroded connections.
Thanks

For the time being I cleaned the battery poles and clamp connectors with a bit of sandpaper.

Is there another way to test the battery and alternator instead clamping the tester directly to the battery ? Can I use the tested connected to the positive side of the battery and then the negative somewhere on the chassis in an attempt for the tester to register the voltage drop or resistance ?

If so where should I connect the negative clamp of the tester ?
 

biomecanoid

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Did you have this problem before you replaced the battery and alternator ?
Yes I had the problem but it was less severe. The car would not unlock from the fob but when inside the car would start fine and this would happen rarely like 2-3 times a year. Now it happened once yesterday and 3 times today

The alternator was changed because it was weak and not charging the battery properly and like 1-2 times a year I needed to disconnect the battery from the car and charge it at home. Once the car died and all electrical systems gone but luckily I was almost home. It would be a real problem every 6-7 months lets say so I lived with it for a while since the remedy was easy.

Now I have a brand new alternator and bigger higher capacity and CCA battery.
 
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It has a battery yes, but I don't think its the fob, because when this happen the car is DEAD, no electricity at all. Plus since yesterday it does not start. You have to keep it turning the ignition for about 10 seconds and the magically it starts
If truly nothing; no lights, chimes, etc., and you are loosing memory settings and the battery isn't drained or bad, I'd be looking for a ground problem like others have stated. Don't take it for granted that it can't be the battery/alt or connections just because you just replaced them. Go back over them. Take them off, clean the posts and connectors on both ends, reattach snug, check for bad spots all along the cables, etc. and don't just concentrate on the battery. Chances are something got loosened or a cable is broken/bad elsewhere that just moving it around when making repairs is causing it to not contact like it was. Check those battery and other cables and wires all the way along the line; not just at the connections.
 
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Thanks

For the time being I cleaned the battery poles and clamp connectors with a bit of sandpaper.

Is there another way to test the battery and alternator instead clamping the tester directly to the battery ? Can I use the tested connected to the positive side of the battery and then the negative somewhere on the chassis in an attempt for the tester to register the voltage drop or resistance ?

If so where should I connect the negative clamp of the tester ?


Did you check the ground?
 
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biomecanoid

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Is there a test I can do to check ground continuity with a multimeter ? or use my battery tester ?
 
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Is there a test I can do to check ground continuity with a multimeter ? or use my battery tester ?

yes, put the voltmeter on the battery ground connection and anywhere on the engine block or head that's metal. Do this with electric loads on like rear window demister, lights and interior heater fan. The voltage should read very close to 0, but if you have a bad ground it could read several volts
 

biomecanoid

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yes, put the voltmeter on the battery ground connection and anywhere on the engine block or head that's metal. Do this with electric loads on like rear window demister, lights and interior heater fan. The voltage should read very close to 0, but if you have a bad ground it could read several volts
Thank you I will try it tomorrow
 
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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
 
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