Parasitic draw - help needed

[Diagnostic Dad]

We have a 2011 Ford Edge Limited which my daughter acquired in the fall to use at a college.  At school she rarely uses it.  After a couple months she started getting symptoms of a dying battery.  She started getting "battery saver" messages on the display.  After couple more weeks it would not start without a jump.  We figured it was just an old battery so we had her get a new battery.  They did a test of the charging system and said there were no problems.

 

A couple of months later the new battery was dead.

 

When she came home I did some in-depth diagnostic testing.  I put a multi-meter in line with the battery to monitor the current draw.  Once the vehicle is "sleeping" I've monitored the current draw.  The normal steady-state is about 17 milliamps.  The problem comes every 15 minutes.  The current draw suddenly spikes up to 2 amps, stays there for around 10 seconds, then slowly drops down to 1 amp over another 20 second before finally plunging back to the idle current of 17 mA.

 

Note that the frequency is a bit faster when the vehicle first goes to sleep.  Initially the frequency is every 5 minutes.  It takes about a half hour before it goes to the 15 minute interval, but it then stays at that interval for a long time.

 

To try to find the problem I started pulling fuses one at a time and seeing if the cycle continues.  I tried all of the "small" fuses in the engine compartment fuse box first with no impact.

 

I then moved on to the interior fuse panel.  The most significant change happened with fuse 6.

Fuse 6 is listed as "RF module".

 

As soon as I pull that fuse the 15-minute high current draw stops.

 

I figured that this circuit is probably for the remote keyless entry system.  Sure enough, with that fuse unplugged the remote doesn't work at all.

I was thinking she could live with using a key to get in, but it also makes the Start button not work.  In fact, when you hit the button the car thinks it is being stolen and the alarm starts going off.

 

Anyway, more research pointed me at TSB 13-6-18.  This specifically deals with a current draw due to the remote system keeping the electronics awake.  I took it to the dealer and they confirmed we had old software and updated the VMCU to version 2.2.14 at a cost of $140.

 

When we got home I put my multimeter on again, waited the car to go to sleep and then watched what happened.

No change.  Every 15 minutes it's still drawing 2 amps.

 

I'm open to suggestions on next steps in tracking this down as long as it doesn't involve leaving the car with the dealer with a blank check.

 

Thanks

 

[WWWPerfA_ZN0W]

you may actually need to replace the module, they do fail from time to time. usually it is the RKE module not the antennas at fault.

 

every time a new battery is installed the battery management system has to be reset so it can recognize the new battery and charge it appropriately.

[Diagnostic Dad]

Many thanks for the feedback.

 

I found this page describing the parts to some degree:

https://www.quirkparts.com/v-2011-ford-edge--sel--3-5l-v6-gas/electrical--keyless-entry-components

In the section near the bottom there are two modules listed, but one is discontinued.

The first module is listed as a "control module" BB5Z-15k602-N, and the description just makes it sound like a radio receiver.

The second module is just called "module" BT4Z-19G481-F and no description of function is given.

Would you happen to know which is the "RKE" module?  If it is the second one is there a replacement part?

 

I hadn't realized about the BMS reset.  The videos I've found all show a car with a key and not push-button ignition.  I'll keep searching for for a video showing this configuration.

[enigma-2]

Do you have an aftermarket remote system? Any electrical modifications done? Any repairs?

[Diagnostic Dad]

No modifications or repairs.  We also don't keep anything like phone chargers plugged in.  I'd say it is completely original.

I'm going to work on on tracking down the modules so I can replace them on her next visit home from school.

[Machman64]

Hey diagnostic dad, I am having the same exact problem on my wife's 2011 edge. It pulls 2.06 amps sporadically, sometimes it's a few minutes and sometimes its five to ten minutes. It stoos when I pull the rf module fuse. Did you ever figure out what the problem was?

[Diagnostic Dad]

Hi Machman64.   No, we never found a solution.  We tried replacing the RF module with a new one and it didn't help.

I'm limited on the time I can work on it because my daughter normally has the vehicle at college.

 

I did end up finding that the RF module seems to be triggering the current draw, but it isn't the circuit actually drawing the current.  In other words, it seems like when the RF module wakes up, it wakes up other systems in the car which cause the current draw.

I've done a bunch more research on it and the module seems to handle both the remote keyless entry as well as the tire pressure monitoring system.  I'm wondering of something with that is causing the waking-up, but I still don't know how to actually fix the problem.

 

Lastly, I ended up getting Forscan with an OBD2 connected in hopes that I'd find something there, but no luck.  When the vehicle goes to see the OBD interface also goes dead, so I can't see what is happening when the vehicle is supposed to be sleeping.

 

My current plan for a workaround hack is to put a physical switch in-line with the circuits that draw current and leave the RF module active.  That should allow the remote entry to continue to work and once in the car she can flip the switch before starting the car.

 

Hopefully someone will post a solution eventually.

 

[Machman64]

Thank you for your response. My next step was going to be to change out the rf module. But it sounds like that's a waste of time. I will keep working  on it and if I figure it out I will let you know.

[Haz]

Below is a PDF download link to a job aid on parasitic current draw analysis...

 

Parasitic Battery Drain Job Aid.pdf

 

Good luck!

 

[Diagnostic Dad]

Slight update.  Still no resolution to the problem.  We have a workaround in place now where I put a switch in-line with the RF module.  We use the physical key to unlock the door then flip the switch to make the key fob work for starting the Edge.  When parking for the night (or longer) we lock the doors by hand and turn off the switch to stop the drain.

 

On a possibly related note, we kept getting the battery saver message even after a long trip when the battery should be fully charged.  We replaced both of the current sensors near the battery and it seems to have resolved that problem.  The radio will keep playing after turning the car off now.  Unfortunately there was no impact on the parasitic drawl.

 

In doing research it seems like this is not an uncommon problem.  I would have hoped someone would have identified the root cause.  I wouldn't mind replacing a module or two if it fixed the problem.

[Cerberus]

3 hours ago, Diagnostic Dad said:

Slight update.  Still no resolution to the problem.  We have a workaround in place now where I put a switch in-line with the RF module.  We use the physical key to unlock the door then flip the switch to make the key fob work for starting the Edge.  When parking for the night (or longer) we lock the doors by hand and turn off the switch to stop the drain.

 

On a possibly related note, we kept getting the battery saver message even after a long trip when the battery should be fully charged.  We replaced both of the current sensors near the battery and it seems to have resolved that problem.  The radio will keep playing after turning the car off now.  Unfortunately there was no impact on the parasitic drawl.

 

In doing research it seems like this is not an uncommon problem.  I would have hoped someone would have identified the root cause.  I wouldn't mind replacing a module or two if it fixed the problem.

while this would not locate or resolve the cause of the problem, this idea may work as a solution to the battery going dead..

have you considered a solar panel on the dash board to charge the battery while the car is parked & counteract the parasitic draw?

 

[ylwpaul]

Hello Diagnostic Dad, 

 

I have a 2011 Edge that has been displaying the same behaviour as what you’ve written about. I get a parasitic draw of 2.2A every 90secs for about 10-15secs. At first I disconnected the instrument cluster because I heard a relay or something making a sound, a tick when the draw started and then a double click sort of noise when the draw ended. But I think that was just a symptom. I also disconnected the APIM and noted that the 2.2A draw dropped to around 450mA but again I think that was just a symptom. Now I believe that the RF module is waking up for some reason which in turn wakes up the instrument cluster and APIM. So the problem I think is the RF Module. I’m wondering where and how you installed your switch? Did you install your switch on the RF Module power supply? Thanks

[enigma-2]

One easy (if not drawn out) method is to hook a ammeter across the battery positive lead and wait until the draw begins. Then start to withdrawal fuses, at the power fuse box in the engine compartment, one at a time. If the draw stops, you may have found the circuit (you'll need to wait until the next parasitic draw begins in 90 seconds to see if drawing out that particular fuse stops the drawl.

 

These can be wierd. I remember one draw was found at a rear wiper. The gears had broken and not allowed the wiper blade to park.

 

Every few minutes the wiper module turnd on to check if all of the wipers are parked. When checking the rear wiper, it found it wasn't parked and attempted for 15 seconds, to park it. Then parked or not, its programmed to stop and begin a timed wait cycle again.

 

15 seconds, hour after hour, the draw added up (after a few days.)

[2016 Edge Titanium AWD]

Good morning All,

 

Add our 2016 Edge Titanium to the group of vehicles experiencing parasitic draw when the vehicle should be asleep. To put context around this, I now believe this has been a hidden 'ghost' issue since we bought the vehicle in June 2019 at 44,000 Kms.

 

Whatever killed the battery actually brought it well below 11 volts over a 4 hour period sitting in the driveway two days ago. The windows were part way down to allow heat dissipation in the cabin, there were no lights on or doors / hatch open and one would think that the vehicle should be asleep. 

 

We were going to go out for an early dinner, and the message on the Sync screen said it had shutdown all unnecessary modules to preserve battery power. The vehicle would not start and putting a Fluke voltmeter across the battery terminals gave a measurement of 3.56 volts. I mean really? 3.56 volts? I attempted to put my electronic battery charger on the battery set to 2 amps, but it kept kicking off because the draw on the battery from whatever was drawing power was much greater than the charger could handle at 2 amps. Didn't try boosting with another vehicle. 

 

I noticed that there was this clicking sound coming from the AC compressor clutch when the electronic charger was first activated, and the symptom would cycle on and off with the compressor clutch clicking on and off every 15 seconds. 

 

NOTE: This is the second CarQuest DieHard battery the vehicle has had since we bought the vehicle used in 2019.  

 

CarQuest was closed so we bought a new Kirkland battery at Costco and installed that in the vehicle so I could at least get the windows up and lock the vehicle.

 

Meanwhile the DieHard battery, immediately taken from the vehicle, slowly recovered to 12.6 volts over night without any help, so I don't think the battery was the root cause.

 

I checked the standby voltage of the new Kirkland battery at 12.27 volts fresh off the shelf, which is a normal reading (with a build date of 11/24 BTW) and proceeded to install it. You can install the battery positive first and then attach the negative cable, but it is easier to connect the negative first, slide the battery back into place and then attach the positive cable. Well, I wasn't particularly expecting a significant spark when I attached the positive cable to the battery, but there it was. And the compressor clutch clicked on the moment the battery was reattached. 

 

OK, now the charging system has a reliable power source and the engine will start and run. I haven't done the battery reset function yet, but I read somewhere that just sitting for 8 hours the battery monitor will reset to the new battery. I may be misinformed. I think there are at least 4 different recommended procedures on YouTube to reset the battery monitor.

 

So then I went into diagnostic mode trying to figure out what was drawing the power (still had no idea how much of a drain it was), but perhaps my 30 year old $300 Fluke meter can help me do that.

 

I've noticed that remote entry may be misbehaving from time to time, for example the vehicle self locks on me at the gas station while I pump gas. In this scenario, the only way to unlock the driver's door (normally by touching the handle) is to open the rear passenger door first. Rolling my eyes!

 

Refocusing on the parasitic draw issue, I noticed that if I leave the AC button on when the vehicle is shut down and parked, there is 'something' drawing power because the voltage will drop from 12.6 volts standby to as low as 12.11 volts over an 8 hour period. However, if I turn the AC off before I shut the vehicle down, standby voltage stays around 12.6 volts. And Oddly, I have two batteries I can monitor as my 'benchmark' for standby voltage, - the recently replaced DieHard that sits at 12.6 volts on the garage floor and the heavy duty 10 year old 12 volt battery in my 1978 Tbird that also registers 12.6 volts while disconnected.

 

I could now pull the fuse on the AC compressor clutch (now that I know where it is), to see if that reduces the parasitic draw, because obviously there is something drawing power when the vehicle should be asleep. BTW, the vehicle has been sitting locked up since 8:30 last night and as of this posting it is 13 hours in sleep / standby. The AC was shut off last night before shutting the vehicle down and locking it, so I'll see what standby voltage is now and report back.

 

I was going to replace the AC clutch relay thinking that possibly it was sticking on when the vehicle was parked but now, after reading through the original poster's story, I think this is more of a symptom than a root cause.

 

Summary:

 

Vehicle Mileage: 101,750 Kms or about 63,240 miles

 

I think that whatever killed the original factory battery 3.5 years into its life may well have been the result of some 'ghost' parasitic draw from some module in the vehicle.  This 'ghost' also killed the first DieHard battery two years after it was installed (and it probably didn't need replacement), and then this parasitic draw attempted to kill a second DieHard making me believe this is not a faulty battery issue at all. It would be great if a simple software update would fix this, but I am doubtful.

 

Thoughts anyone?

[2016 Edge Titanium AWD]

Opening the vehicle to release the hood latch partially woke the vehicle up, and first measurement of standby voltage was 12.38 volts. However, as the vehicle went back to sleep, the standby voltage rose to about 12.45 volts and climbing. Hood is open now, so I'll check again in about a half hour.

 

Update: 12.56 volts standby 

 

Cracked the rear windows open and put the sun shade on the windshield; - a tad warm here in Niagara Falls Ontario today - 31C with the Humidex: 38C 🥵

Edited 14 hours ago by 2016 Edge Titanium AWD

[gonesail]

a fully charged 12v battery at rest is around 12.6 or 12.8 volts. but i have learned that these vehicles all have some level of parasitic draw. even staying alive waiting for you to unlock the doors takes something. but taking a battery down to 3.56 volts will definitely shorten battery life. i always turn the AC and wipers off before shutting the car down but that's just me.

[2016 Edge Titanium AWD]

One final note while many of the folks on the forum wait for a solution that works to be posted. After installing the new replacement battery, my wife took the vehicle shopping the next morning. I had turned the AC off the night before and reminded her that it would likely still be off when she started the vehicle. It was off, but she insisted that before she turned it on the re-circulate light was on even though the AC was off. Of course it automatically turns on the re-circulate when the AC comes on to help cool the cabin down.

 

Went out later and tried to duplicate the scenario where the AC is off but the re-circulate comes on anyway. I wasn't able to duplicate it but something completely unrelated happened while I was doing my checks. The engine check light came on, and so I shut the engine off, and tried to see if it was an intermittent fault be restarting the vehicle several times. No dice.

 

Figuring that the most likely sensor to trigger the ECL was EVAP, I shut the engine off, took a rag with some mineral spirits and wiped the inside of the 'fast fill' cap where the inner flap touches the inside of the filler neck. Let it dry for 5 minutes, re-started the vehicle and the ECL was now out.  OK, I'll take that as a win!

 

Which all leads me to wonder if every root cause of parasitic draw may be different based on what module is misbehaving. In one case it may be the RF module, or perhaps the HVAC module or even both at once (I believe there is even a trailer towing module) which further leads me to believe based on how many modules make up the complete vehicle, any combination of them could cause parasitic draw individually or in combination.

 

Need to get back to basics I think. My '78 Tbird only has a fuse panel with 8 or 10 fuses, and pressing the trunk release when the AC compressor kicks in will blow the fuse because they are both on the same circuit. Go figure!

 

Cheers, Everyone