Parasitic drain/draw

10780 Views 68 Replies 15 Participants Last post by murcod, 16 d ago

alcatraz

Discussion Starter · Aug 12, 2021

2017 Escape Titanium 2.0L FWD no aftermarket additions, new battery less than one month ago, ForScan BMS reset,

I disconnected the battery about 4 hours after driving it, contrary to the latest recommendations as to how to do it without disconnecting the battery, but if I don't do it for this test I'll have to disconnect it if it's not driven every day. Tested amps between positive post and cable. Initial draw was 4 amps, and then over the next 4 minutes it gradually dropped milliamps through the ranges down to .370 and stayed there. I'm wondering what the most likely culprit is. The underhood fuse box has lots of square larger amp fuses which will have to be pulled to check, so I can't just use the probes on them like on the smaller fuses (I don't think that's possible...correct me if I'm wrong.) Checking all the smaller fuses yielded no results--0.0 on all. Battery was at 12.7 volts, and the automatic charger at 2 amps does not indicate a full charge, so I'm leaving it on for a few hours. Is the alternator a prime suspect on these? I'll disconnect it and see if it makes a difference. I'm guessing that has to be done from underneath. I have a spare alternator, but are the diodes in these easily replaced. I like to have a spare with me on long trips. Thanks for any similar experiences you may have had.

1 - 19 of 69 Posts

murcod

· #2 · Aug 13, 2021

Assuming the 2017 functions similarly to the earlier models, the light circuit is powered for about 12 minutes after the vehicle is locked. That's going to interfere with the measurement you got after 4 minutes.

You haven't mentioned why you think there is a parasitic drain, what exactly has been happening? Is anything left plugged into the cigarette power outlets as they're permanently powered.

murcod

· #6 · Aug 13, 2021

alcatraz said:
Reattaching the battery cable creates a pretty good spark when it first touched the post.

That's totally normal and not a sign anything is wrong with your vehicle.

murcod

· #8 · Aug 14, 2021

alcatraz said:
I haven’t disconnected the alternator yet because lying on my back under a car always makes me nauseous but looks like I’m going to have to do just that.

Pulling the relevant fuses would be far easier.

murcod

· #33 · Oct 9, 2021

ForScan is the best way to see what's going on - then you can directly read the SOC figure the BCM has calculated. Using voltages to determine the SOC can give false readings. Also check the charging voltage while you're driving and see what voltage/ charge current ForScan says you're getting fed into the battery.

murcod

· #35 · Oct 10, 2021

Your charger should be charging the battery up to around 14.2 to 14.4 Volts, it should hold the battery at that voltage for a period of time (a couple of hours) and then drop it back to a "float voltage" of around 13.6V.

It could be worthwhile (given the issues you've got) buying a Bluetooth battery monitor. They hook up across the battery and log the voltage - so you can get a voltage vs time graph which shows you what is happening - whether it be charging the battery, leaving it sitting or driving. In Australia they cost around AUS$50 and there's an app that you run on your phone. (Something like this https://www.amazon.com/QUICKLYNKS-Battery-Monitor-Bluetooth-Device/dp/B01MT4583U/ ) You don't need your phone connected all the time as the monitor stores the voltage data and downloads it to your phone when you next open the app.

See less See more

Reactions: 2

murcod

· #37 · Oct 11, 2021

If it's a smart charger (three stages or more) then it would be safe to leave it connect permanently when you're not driving it. Perhaps give that a try as your battery may not be fully charging.

I've got a spare Bluetooth battery monitor (basically the same as what I've linked to on Amazon) so I might install it on my Kuga. It will be interesting to see what actually happens (charging voltage wise) while driving.

(I'll also split some of these charging related posts into their own thread- given we're in a thread on resetting the battery monitor system.)

murcod

· #38 · Oct 11, 2021

@alcatraz @wiz043 @ralph7up I've moved the posts discussing the battery charging/ voltage drop when left sitting from the BMS Reset thread to this thread.

Reactions: 1

murcod

· #41 · Jun 8, 2022

BNault said:
I was able to get it isolated down to MEGA 4 50 Body Control Module (see below) wire, with this disconnected i was under 1 amp draw.

I've got the 2013 model wiring diagrams and it shows Mega Fuse F4 as going straight to the BCM on plug C2280G pin 2, Mega Fuse F9 also is shown going straight to it.

I'm wondering - you disconnected all the BCM connectors on the side where the fuses are? C2280G is the plug directly above the fuses on the BCM with only two large gauge wires going in. Disconnecting that should have the same effect as pulling Mega Fuse F4 and F9. (Unless there's details missing on the wiring diagram?)

Are both your battery terminals and the BMS sensor wires in good condition with no corrosion?

murcod

· #42 · Jun 8, 2022

F41 in the engine bay Battery Junction Box is also listed as supplying the BCM (with "F85,F86" listed after the "BCM"), I'm guessing that's to signify those fuses on the BCM are supplied by F41. Perhaps try pulling that with the Mega Fuses fitted and see what happens.

murcod

· #43 · Jun 8, 2022

F22 is also connected to the BCM via the BMS current sensor.

murcod

· #45 · Jun 8, 2022

Also try pulling F23 in engine bay Battery Junction box (with the Mega Fuses installed), that supplies power to the Ignition and Acc Power Delay relays, which are earthed out by the BCM to switch them on.
F41 is also supplying power to the BCM.

murcod

· #46 · Jun 8, 2022

The BCM contains quite a few relays inside it- so possibly one is stuck closed?

BNault said:
Side note if i remember right I seen the remote start receiver spliced off that red wire before it got to the BCM, and I didn't see that in the diagrams (it was disconnected same time I did the BCM).

So that's an aftermarket/ dealer fitted accessory that's been added?

murcod

· #48 · 12 mo ago

BNault said:
I found that opening MEGA 5 (Electric Booster Heater)

Is that Electric Booster Heater something fitted in cold climates?

You're making good progress with the fault finding.

murcod

· #49 · 12 mo ago (Edited)

Some info:

The BCM switches on the electric booster heater depending on the following parameters:
-Engine coolant temperature is below 60 °C (140°F)
-Ambient air temperature is below 10 °C (50°F)
-Sufficient generator capacity is available
The electric booster heater electronics activates three output stages depending on a PWM signal generated by
the BCM . The output stages switch the three heating elements of the electric booster heater ON or OFF
individually, allowing the heating periods of the individual elements to overlap. Due to the variable switch-on
duration, continuously variable temperature control is possible. The overall heating power of tee heating
elements is linearly proportional to the PWM signal. If the PWM signal is below 10% or above 95%, the
electric booster heater is not activated.

Edit:

F5 is shown as connecting directly to the Booster Heater.
BCM plug C2280F pin 17 goes from the BCM to the Booster Heater (along with heated seats etc.) It's 12V IGN supply via F85. I didn't find the PWM signal feed from the BCM.

See less See more

murcod

· #51 · 12 mo ago (Edited)

BNault said:
Not sure if it's fitted in cold climates mainly, but that would make sense.

I know with the Kuga there are different climate "specs" listed on ETIS. Mine doesn't have the heater booster and ETIS says "Warm Temp Zones", "Less Heated Windscreen", "Less Heated Washer Jet", "Less Engine Block Heater", "Less Auxiliary Heater" in the specs. I know the UK gets some sort of heater booster and also a windscreen defroster (heated wires built into the screen.) Perhaps all North American vehicles get the heater booster?

murcod

· #57 · 3 mo ago

Pilottjl said:
My bill states it was circuit CDC34

What year model is your Escape?

I found that circuit mentioned for a 2010 and 2012 model here :

2012 Ford Escape XLT 2.5L Run Circuits

All run circuits intermittently stay live, so vehicle does not shut off. CDC34 white w/ orange tracer does not power down even if you disconnect the ignition switch. I traced the problem to the portion of the circuit going to the smart junction box, i.e.,t...

www.iatn.net

2012 Ford Escape XLT 2.5L Run Circuits

All run circuits intermittently stay live, so vehicle does not shut off. CDC34 white w/ orange tracer does not power down even if you disconnect the ignition switch. I traced the problem to the portion of the circuit going to the smart junction box,

https://f01.justanswer.com/dcraig1000/dae56ca4-22a0-470c-bd34-efa9b1b94dc9_eee.pdf

CDC34
(WH-OG)
18
SWITCH - IGNITION #
RUN; START

I've got the workshop manual for the 2013 Escape and don't get any hits searching it.

See less See more

murcod

· #63 · 27 d ago

IrnBru said:
The selling dealer has offered to take the car back for what we paid since the Ford dealer says its unrepairable. Hard to believe a 2019 Ford with 60,000 miles that has battery drain is unrepairable.

That's crazy. They must have run out of flow charts to follow in the WSM .... so threw the towel in! 😆

Are you going to take up the offer?

murcod

· #67 · 26 d ago

IrnBru said:
Probably, we looked at a 2019 Rav4 last night

Yes, I had a look at one when I bought a Yaris in 2020- they're very nice inside compared to my 2016 (Sync2 update) Kuga. The drivetrains aren't very inspiring though.

murcod

· #69 · 16 d ago

IrnBru said:
We did get the Rav4 and it's very nice. I'm so disappointed in the quality and ability of the Ford to be repaired. I was born into a Ford family but I'll probably never buy another after this experience.

I always buy whatever brand/ model suits my desires best. I don't understand people who have to buy the same brand all the time, but know a few people who do that.

Good luck with the Rav4.

1 - 19 of 69 Posts