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Ford Focus MK3 2014: Battery drain causing alarm trigger


Shahman
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Hi all, I've been trawling the forums for a while - and now the time has come to seek some help.

I have a ford focus 2014 mk3, 1.6 TDCi, I usually drive 100miles a day round trip for work. Recently my car alarm has been going off every couple of hours and I think iI've narrowed it down to a possible battery drain.

battery volatge readings were 12.2v with a multimeter - so i bought and fitted a new battery incase it was a faulty battery. However the new battery is now (within 3 days of installing) reading sub 12v and my car alarm went off last night.

 

I have carried out a parasitic drain test:

  • First I measured the mV across the minifuses in the engine bay with a multimeter, however they all fell to 0mV, which indicated no current draw. I was unable to test the fuses circled in red.
    Ford-Focus-2012-2014_20180514114241566_12.thumb.jpg.23dde889f097d02d04c18b54a7ac3518.jpg

 

  • I then used the 10A Current setting to measure the current draw direct from the battery by placing the multimeter leads inline from the positive terminal of the battery and the positive cable. I tripped all the door and bonnet latches to make the car think they were all closed. And i waited 5-10 minutes for the readings to stabilise. This threw up some strange results:
    • While the car was unlocked the readings fell to 0.008mA which is within spec
    • When i locked the car with the remote the draw stayed at 0.400mA - (I wanted to wait longer but i dont have croc clips, and had to hold the tester leads manually)
      So I pulled the fuses in the passenger foot well relating to the PATS system but this didnt affect the current draw.

 

  • The incar displays all turn off when the doors are closed and then locked with the key - so no obvious CAN system fault keeping things awake...

I've got Forscan and Focccus set up and trying to do a little diagnostic there -  Forscan showed a Current draw of -8A when the car was off however some auxilliary system were powered but nothing that should be pulling 8A in my opinion.... It also showed a battery voltage of 11.9v and a SoC of 27%

Another thing i have noticed is my aftermarket DRL now stay illuminated after the alarm has gone off despite the car being off and relocked...

Despite all this my car has no issues turning on and driving.

 

I've read some people with similar issues had faults with the bluetooth / SYNC module but im not sure how to diagnose that. And additionally I've read that washer fluid can leak into the BCM panel and corrode pins - but I assume this is a problem on left hand drive  cars... since the washer fluid is on the opposite side in my car... Also im not sure how to disconnect those wire harness connectors to check the pin.?

 

I've got the battery back on charge - frpm the wall - and will re do the drain test with some croc clips tomorrow hopefully and allow the car to  sit for an 1hr then start pulling fuses if i see a draw....

 

Any tips or ideas  before i give in and go to the dealer or find an auto electrician??

Thanks!

 

 

 

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Did you know that FORScan should have a PID in the BCM that shows you what caused the last 4 alarm events, it would be a good idea to check this to see if it is the battery that is setting the alarm off.

I don't know if you have done this but It is recommended that the BMS is reset when a new battery is fitted. If you did not it may account for the low state of charge reading. You should be able to do this with FORScan or through the series of button presses. 

I have a MK4 and I also have a current draw of around 8 Amps with the ignition on engine off,  double that with the automatic headlights triggered and the heater fan running, and the voltage can typically be between 11.7 and 12. I don't know if the MK3's should be the same.

 

 

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Hey John,

I did check Forscan for the PID for the alarm trigger they all said 'Start Attempt' or something like that - but i couldnt find anything online to what that means

I have reset the BCM through Forscan and manually to no effect - even Forscan recognised the battery was 0 days old.

 

Thanks for the help though!

 

However I may just have discovered something - I just noticed that my dashcam is not turning off once the ignition if off - usually it would turn off as soon as i opened the doors to exit the vehicle after turning the engine off. It seems to remain powered on - i will need go check in 20/30 mins but its drawing about 0.7A while the car if off and centrally locked...

I'm not sure what has caused the 12v socket to stay live / the dashcam not to turn off.... hopefully this is the cause of my problems....

 

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Quick update:

The dashcam shuts off after 20 mins - so it's just the slight delay on the 12v cigarette lighter port...

 

Redone the battery drain test with the ammeter croc clipped onto the battery and waited 30 mins and the current draw falls down to 0.033A when locked... So surprisingly nothing seems to be draining the battery???!?

 

Now I'm completely lost... Brand new battery, flat within 3 days... No battery drain.  

Help!?

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1. Is the alternator charging the battery? What voltage do you read at the battery with the engine running (expect about 14.5v).

2. Did you reset the battery monitoring system when you fitted the new battery?

3. It is possible for new batteries to be faulty.

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Hi Paul

I get 14.5v with the engine running - so i think the alternator is good charging

Reset the BMS both ways through forscan and manually

Possibly the new battery is dud - but unlikely?

 

Checking the OBD2 codes i have an:

Igintion Relay fault - Short circuit to ground 

 

Which lines up with my Alarm trigger cause history:  Start Attempt

 

This could be why my alarm keeps going off - and the alarm is what is draining my battery not a parasitic drain...

 

But i've checked the relay and its operating fine.... although one of the pins in the relay holder reads 1.2V respect  to ground AND positive on the battery,,,, The rest all read 0 wrt ground and 12.3 wrt positive.

No idea if this is normal...

 

Another peice of information - my Auto Start/Stop has not been functioning since a gearbox refurb last year. not sure if this ties in at all....

 

 

I'm going to make a new post becuase i no longer suspect its a battery drain - and hopefully someone with an idea of the OBD2 codes / Ignition wiring can help.

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  • 6 months later...

Hi Sorry had to Jump on this was there an outcome for this as i am having the exact same issues right down to the engine not cutting out until i open my door i have every issue you have posted about this has been over 2 weeks and run out of ideas.

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