Jump to content
Do Not Sell My Personal Information

Parasitic Battery Drain


Recommended Posts

Hello I have recently had a parasitic battery drain on my Focus 2012 TDCI 2.0. (using a new thread since the old one was about chimes)

After running a few tests, 1.1amps was escaping the battery over the course of the day nonstop. This has led me to jump starting the car as I don't have access to the vehicle or another person who can make sure the battery stays alive as I have read across the forums that leaving the battery below a certain percentage is not the best thing to do, unfortunately this has been the case for the last few days, as I do not have access to the car outside of 8+ hours at a time some days.

The battery was changed as the garage initially thought it was the battery at first, and the problem persisted. In the end, I decided to do a few tests and see what was wrong. The alternator and the battery are in working order, 1.1 - 1.2 amps were being picked up by the meter during sleep mode. (30 - 40 minutes later) After taking out fuses one by one once the car had been idle for 30 - 40 minutes, I managed to get the amp reading down to the lowest off 0.02, with the highest being 0.04. The culprits being the following:

Fuse 2 Boot - Keyless Vehicle Module (5amp) | This I can understand as I have had issues with the keyless entry to the vehicle 9 months ago, I can lock the doors by using my hand, but cannot open the doors by placing my hand behind the handle. I have also had issues in the past (2 to 3 times) where the key was not recognised until the alarm went off as I had to use the key manually to open the door.
Fuse 69 Passengers - instrument Cluster (10amp)

Removing one or the other would reduce the amp reading from the battery to 0.6ish, removing both would take the reading down to 0.04.

Any help? thanks! Unfortunatly eletronics and cars are not my strongest point, thankfully forums and the internet are full of information, I know I have to follow the circuits and find a potential cause, but thought I would ask if there is any alternatives first.

Link to comment
Share on other sites

giving you a few mins to think " whats this idiot on about. "
probably the kve is staying awake and keeping the cluster awake .
try fixing the door handle issue.
needs removing, dismantling, cleaning all parts with clean water then spraying with the above spray.

  • Like 1
Link to comment
Share on other sites

Those faults are probably linked the key less module isn't telling the instrument cluster to go to sleep hence the drain.  I would start by checking the wiring to the keyless module to make sure the connection isn't loose and check for corrosion.  To be honest there isn't a lot a DIYier can do with CANBUS systems as they are quite complex.  Might be worth running a diagnostic check on the car using ford scan to check all modules for faults.  Ford might also be able to update the software to correct this fault.

Link to comment
Share on other sites

  • 5 months later...

My daughter has this problem with a blue keyless focus. Both myself & my son are electronic engineers and we have been trying to solve this for over a year. Symptoms are over the weekend if not used or charged the battery dies. There is a drain and we have come down to the radio and front windscreen fuses but haven't got any further. Daughter decided to DOR and found that if she didn't use the keyless system then the car is fine. Its been three weeks now. I have read about the PCN module and the microswitch. Has anyone actually cured this problem themsleves as all I read about is moans and you cant trust a dealer to tell you the truth.

Link to comment
Share on other sites

  • 2 years later...

Has anyone found the cure for this fault. I’m having parasitic drain over night, if I remove 10 amp fuse 2 for keyless vehicle module the battery does not drain, however the car will not start then unless I put the fuse back in. When fuse is fitted the key fob works to unlock doors and I can then start the car.

Link to comment
Share on other sites

  • 3 months later...

So many of us have this issue and yet no-one seems to have a fix for it, not even the garages!!!! It's so frustrating 

Link to comment
Share on other sites

Latest Deals

Ford UK Shop for genuine Ford parts & accessories

Disclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via the club

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...