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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
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Experience:  16 years experience
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2011 F150 XLT, 5.0, 12-2010 build date. 4.2 amps of

Customer Question

2011 F150 XLT, 5.0, 12-2010 build date. 4.2 amps of parasitic current draw after 12 minutes of KOEO all lights off, door switches shut, locked and armed. Pulled fuse 18 from fuse block located at passenger foot well and current dropped to 20mA. Plugged fuse back in and current rose to 1.2 amps. After a few minutes current dropped to 20mA. Fuse 18 is for brake-shift interlock, keypad illumination, PCM wakeup, PATS. What is not allowing the PATS, PCM to go into sleep mode after KOEO?
Submitted: 8 months ago.
Category: Ford
Expert:  Adam Legler replied 8 months ago.

Hello, my name is ***** ***** I am a Master and Advanced Level Certified Automotive Repair Technician with over 12 years experience and I've personally worked on over 25,000 vehicles. I see you have a question about your F150 and I think I can help you.

About 2 weeks ago I took care of a client that had the same concern as yours. I know we have a suspect of the PATS, however what I would like to do first is a simple yet effective test. With the vehicle off, doors shut, do you notice that white lights on the cluster are staying on?

Again, please feel free to ask any questions that come to mind. It is my goal to determine the cause and remedy for your concern. I look forward to a speedy repair! Thank you.

Customer: replied 8 months ago.
The cluster lights stay off after BCM countdown.
Expert:  Adam Legler replied 8 months ago.

Interesting. And just to confirm you do NOT have any type of aftermarket electronics installed in the vehicle? Meaning remote start (other than factory), alarms, radio, topper, light controllers, etc...

Customer: replied 8 months ago.
All factory. I do hear an electronic "noise" like a faint hum around the alternator area.
Expert:  Adam Legler replied 8 months ago.

Ok, that's great info. The buzzing around the alternator is very interesting, have you tried simply unplugging the small connector from the alternator?

I'm sorry I have to ask this next question:

On the next post I'll have one more test for you...

You are waiting 45 minutes before taking your draw reading and you are testing the vehicle will all doors and hood "shut" or at least tricked shut? This is fords walk-down on how to properly test for a parasitic draw. Hope you understand why I have to post this, just want to make sure we're all on the same sheet of music.

Informational Bulletin Only. This bulletin was created to address the correct procedure for detecting a battery draw on newer Ford, Lincoln and Mercury vehicles. To test, have the driver's door open and latch shut to simulate a closed door and be able to access the interior fuse box. Next, disconnect the negative battery cable and install an ammeter between the post and the cable end. With the meter connected, momentarily reconnect the cable end to the battery post to recharge the capacitors in the vehicles modules without disturbing the meters leads. You may use a jumper cable to jump from the post to cable end if it is easier. Depending on the vehicle and number of accessories, current draw at this time will be between 110 Milliamps (MA) and 850 MA, (with most vehicles ranging between 200 and 500) for a period of up to 50 minutes. This will be a normal reading until the vehicle enters sleep mode. At this time the draw should be under 50 MA. An input such as a door being opened, a button on the Key Fob or the Remote Keyless Entry pad (if equipped) being pushed, lights being turned on or a key placed in the ignition will cause the vehicle to wake up again which requires another "wait to power down sequence" to start. If the draw is higher than normal before sleep mode or never goes to sleep and fluctuates up and down there would be an input to a particular module commanding some response. To diagnose, start pulling circuit fuses and leave out until you find the one that puts the value at the expected awake mode reading or under 50 MA if the vehicle was in sleep mode and address that circuit. Never pull the module fuses or relays as this will change the values when re-installed.

Expert:  Adam Legler replied 8 months ago.

It sounds like you have the testing part down pat though

Expert:  Adam Legler replied 8 months ago.

attached is a picture of connector C405 in the rear of the truck, I have read instances where this connector can corrode on the inside an back-feed voltage to the BCM.

Simply pull down the connector and see if there is any corrosion growing inside or on it. It may look like white scale, however more commonly it is a green colored type of calcification.

Customer: replied 8 months ago.
I've tested just like your description. The truck has to be started (with a large gauge cable attached between the disconnected negative cable and the negative battery post) then shut off, 4.2 amps well after 1 hour of waiting.
Customer: replied 8 months ago.
I did pull apart c405 last Sunday. I found water in the connector but no corrosion. I did blow dry out both ends and inserted dielectric grease into the pin holes. Truck did not start next morning.
Customer: replied 8 months ago.
Start/run PCM?
Customer: replied 8 months ago.
Btw, brand new battery, reset BMS for new battery with Bosch DTC hand held,
Expert:  Adam Legler replied 8 months ago.

Great, it seems you know your way around. The 2012 F150 5.0 that I repaired the other week was a bad gearshift unit, and according to my research at the time, it was actually the number one cause for a parasitic draw. For testing purposes, I'll share the diagnostic steps:

Please let me know if you have any questions for me prior to proceeding. Since there is specific testing involved I'd like to know you're comfortable with the above steps and tools necessary for accurate diagnosis. I will lay out the procedures and you can report back your findings.

  1. Monitor the voltage signal of the Dark Green (DG) wire at the brake shift interlock connector using a multi-meter. This circuit should indicate low (grounded) voltage with the ignition on and the transmission in Park. With shift lever out of the Park position should indicate over 8 volts, again, with the ignition is on.
  2. Failure of the shift lever unit to ground the DG wire in the Park position of the transmission will generally cause the P in the PRND2L display to not illuminate in Park and the noted cluster lights will stay on when the ignition is turned off, creating a drain, this can also be an intermittent concern.
  3. If the Dark Green (DG) wire shows low voltage even when the transmission shifter has been removed from Park, disconnect the shift lever connector and verify that the voltage of the DG wire increases to more than 8 volts indicating failure of the shift lever unit.
  4. If the voltage on the DG wire is low even when the shift lever connector is disconnected, check for the DG wire to be grounded in the wiring harness running between the cluster and the shift lever unit.
Expert:  Adam Legler replied 8 months ago.

a battery was on my list, apparently the ford electronics are getting like GM's now: power hungry, average battery life around 2-3 years.

Expert:  Adam Legler replied 8 months ago.

Additionally, there are instances of alternators causing this issue as well as that connector C405

Customer: replied 8 months ago.
Adam, I am not able to perform your prescribed testing for about 45 minutes. I will report back after
Expert:  Adam Legler replied 8 months ago.

No worries, I need to step away from work for a minute to run a couple errands. Simply post your findings and I'll reply back as soon as I check back in. Thanks again!

Customer: replied 8 months ago.
I don't have test leads small enough to fit in the connector
Customer: replied 8 months ago.
I sent 2 videos your way. Let me know if they prove correct operation of brake/shift interlock
Expert:  Adam Legler replied 8 months ago.

Ok, sorry about that delay. I have not received any videos yet, did you use the attachment feature?

And I wanted to suggest if you dont have test leads small enough you can always "poke" into the wire with a safety pin and read off of that, just be careful that it does not touch anything! In my electrical testing drawer I have little "t" handle pins that are used for small wood hobbies.

Let me know on the videos though, I'm anxious to see them.

Customer: replied 8 months ago.
Ok. The videos are too large. I now have proper test leads. Am I measuring between DG and chassi ground?
Expert:  Adam Legler replied 8 months ago.

correct, since we are testing for voltage you will connect the other lead to a really good chassis ground. If in doubt on where to ground, a good place is the door striker on the b-pillar, that is where the latch grabs on to and holds the door shut.

Sorry about the videos, I've noticed sometimes the iPhone videos are very large file sizes, if that's what you have

Customer: replied 8 months ago.
Ok. A lot of info here....
Millivolts in park, key on engine off
10.2 volts when I pull the shifter
Also the little white disk pops out when I press the bake pedal
Customer: replied 8 months ago.
Something to note;Key off but left in ignition, doors closed, wait until courtesy lights go out, pull key out of ignition and the PRNDM21 light flickers and the tach and speedo needles bounce a bit
Expert:  Adam Legler replied 8 months ago.

Very interesting! We may be defiantly looking at the shifter assembly, one moment please.

Customer: replied 8 months ago.
Now the needles don't bounce when I pull the key out. The cluster lights flicker while pulling out the key. Is that due to a relay turning on the dome lights?
Expert:  Adam Legler replied 8 months ago.

Ok, I've determined that our issue lies in a faulty gear shift lever unit. Since the DG wire did read over 8 volts according to Fords diag tree this is a faulty unit. If you want to done another test, you could ground pin 3 at gear shift assembly (green wire) and the lights should shut off after 3 seconds approx.

Let me know if you would like to have the remove and replacement steps for the lever unit. As you can imagine it will be a dealer only part.

Thanks for letting me assist with your concern, definitely keep me posted on your repair progress!

Customer: replied 8 months ago.
I'm a bit confused. DG does read higher than 8 VDC when not in park. 10.2VDC. When I put it back in park DG reads .014VDC
Customer: replied 8 months ago.
Also I've been reading 4.2 amps of current draw for 40 minutes. I pulled all of the connectors in the steering column. The current still is 4.2 amps. The feedback noise is still around the alternator.
Expert:  Adam Legler replied 8 months ago.

I apologize, it looks like I read your answer wrong. No worries! Did you try to pull that small connector out of the alternator?

Expert:  Adam Legler replied 8 months ago.

Also is the "P" for park illuminating on the dash when the vehicle is turned on?

Expert:  Adam Legler replied 8 months ago.

getting deeper into this possible shifter, i assume you do have the column shifter correct? Not too much different if you have the floor shifter, but it does change the wiring diagrams

Customer: replied 8 months ago.
column shifter. Key off or on the P lights up when gear shift lever is pulled. I can hear the switch click on and off.
Expert:  Adam Legler replied 8 months ago.

Well, judging off the 8+ volts OUT of park, the ground while in park, the "P" indicator working correctly, it sounds like we've almost ruled out the shifter, however the cluster lamps flickering throws the whole diag tree off kilter. Give me a moment while I look for any info on that IPC going out/staying on

Expert:  Adam Legler replied 8 months ago.

Did you try unplugging the connector out of the alternator?

Customer: replied 8 months ago.
I'm having a terrible time getting the alternator plug out.
Expert:  Adam Legler replied 8 months ago.

yeah, i can imagine so being on the bottom left of the motor, the insulting part is the labor guide lists a whole whopping 0.5hrs to remove and replace it

Customer: replied 8 months ago.
I cannot get the plug out of the alternator without removing the entire alternator. So while under the truck I thought "geez, sounds like the feedback noise is coming from the EPAS. I unplugged both of the connectors at the EPAS and a few minutes later I heard a relay click and my current draw is back to 20mA. Yikes!
Expert:  Adam Legler replied 8 months ago.

This is such an odd issue. Between the power steering staying on, the gauges flickering, and full circle to your ~5amp draw, and fuse 18 eliminating the draw, its possible "something" is not allowing the vehicles ACC delay relay to turn off. If this was 5 years older I'd have you looking at the door ajar switches within the door itself, however that not being the case I'm sorry to say that i am running out of ideas.

I ran this info across a colleague at Ford, he's got 30 years as a double master Ford certifed technician and he stated the only things he's seen cause this on this generation of f150 are bad batteries, he did say not to use a Bosch battery, the shifter unit, or the alternator. He agreed that the PCM power relay may not be getting the ground from the PCM to deactivate once the vehicle is off, and that could be due to a bad relay, wiring, or even a PCM, but he had never had an instance of that.

I'm going to pull a wiring diagram of fuse 18, bear with me one moment

Expert:  Adam Legler replied 8 months ago.

okay, so I could not find a specific diagram having to do with Fuse 18 out of the passenger footwell, but I have connected a couple dots. That fuse block is the BCM (Body Control Module), the accessory delay relay, which basically handles turning the vehicles power on and off is physically part of the BCM internal circuit-board (on most models). I also came across a recall FOR the BCM having to do with a wiring issue causing a fire hazard. I wonder if this potential short could be happening causing your draw and your gauges bouncing all over. I've attached the first page of the dealer recall, it may apply to your vehicle, if I have your license plate number I can tell.

Expert:  Adam Legler replied 8 months ago.

NOW I have attached that page

Expert:  Adam Legler replied 8 months ago.

also let me know what state the license plate is from

Customer: replied 8 months ago.
Very strange indeed. Now I have put everything back together and my current draw is now about half and the feedback noise from the alternator/EPAS is gone. Can I ask why you need my license # ***** of the VIN?
Expert:  Adam Legler replied 8 months ago.

just an easier way for most people for me to get the vin number, a lot of people have no clue what it is

Expert:  Adam Legler replied 8 months ago.

and that is still A LOT of draw, unless were still within the 50 minute waiting period.

Customer: replied 8 months ago.
a lot of draw, but only about 30 mins. in this test. VIN# *****
Expert:  Adam Legler replied 8 months ago.

Darn, no active recalls.

This is an excerpt from the CARFAX Vehicle History Report.

DateMileageService Performed

02/19/201641,000Passed emissions inspection

02/12/201418,000Passed emissions inspection

08/19/201314,771Maintenance inspection completed
Computer reprogrammed
Tire condition and pressure checked

05/29/201312,538Maintenance inspection completed
Airbag clockspring/reel replaced
Body electrical system checked

04/15/201311,478Maintenance inspection completed
Cruise control switch replaced
Battery/charging system checked
Engine/powertrain computer/module checked
Tire condition and pressure checked

Expert:  Adam Legler replied 8 months ago.

So lets review:

Expert:  Adam Legler replied 8 months ago.

Common causes of draw on this model

  • gear shifter
    • ruled out by "p" in operation on IPC, over 8 volts when out of park and ground when in park
  • draw eliminated by fuse 18
    • brake-shift interlock, keypad illumination, PCM wakeup, PATS
      • The PATS system cannot stay on by itself, it would have to be on with the IPC
      • Same with the brake interlock, it will work normally regardless of key position for the sole function of the brake lamps
      • key pad illumination - uses LED's, impossible for the actual light to cause that large of a draw
      • PCM wakeup, or accesory delay is the only possibility
        • no way of actually testing the relay since it is part of the BCM, a Ford IDS would be able to tell us if it was remaining on
        • this function also NEEDS to see all door and hood closed, regardless if they're open or not
        • also we have made sure that NO aftermarket accessories are present
  • Possible alternator
    • unable to test due to location of connector

And now the draw is half of what it was just from reconnecting everything. Odd issue indeed.

So based off this, the only thing TBD is the alternator, and possible BCM issue.

I'm sorry I cannot help narrow this down anymore than that. Officially at this point I'll be opting out of this discussion, opening it up to someone else. I hate to do that considering the time I and WE have invested in the issue, however I feel if we continued I would be doing you a disservice. If the vehicle was at ford they would most likely at this point throw a BCM at it and program it, in the technician world this practice use to be very common, the diagnostic tree ended with "replace with known good part".

Thanks for working thru this with me and your patience. When you do get your concern remedied I'd love to know what it was. If you have any additional questions please let me know, I'd love to help.

Customer: replied 8 months ago.
still 2.1 amps at the 50 minute mark. Not sure what's next. I need to call it a night however.
Expert:  Adam Legler replied 8 months ago.

No worries, thanks again

Expert:  Chris (aka- Moose) replied 8 months ago.

Welcome, I'm Chris (aka Moose). I normally log in after 3 pm central. Please make sure to let me know exactly what is needed from me so I can provide EXCELLENT 5 STAR service.

Different tech here, the other opted out. Would you like me to try and figure this out?

Customer: replied 8 months ago.
of coarse. I'm still having the parasitic draw issues. Are you able to review the history of what the previous tech has gone through with me?
Customer: replied 8 months ago.
Hi Chris. I'm hooked up and parasitic draw is 4.2 amps at 10 min. in. Feedback humm can be heard from around the alternator
Customer: replied 8 months ago.
I started pulling fuses in the power distribution box. When I pulled fuse 53, the run/start -PCM fuse, my current dropped to 86mA. Still a little high but only 20 mins in on draw test.
Customer: replied 8 months ago.
Just now final communication took place. Current jumped to 1.2 amps for about 10 seconds and is now 40 mA
Customer: replied 8 months ago.
I wish I could get some confirmation on this:So earlier when I pulled fuse 18 (brake shift interlock, keypad illumination, PCM wake up, PATS) located in the passenger footwell fuse block the current dropped due to opening the relay that switches the run/start relay. Now how to replace the run/start PCM?
Customer: replied 8 months ago.
Or is it something in the ignition switch? Hello? Buhler?
Expert:  Chris (aka- Moose) replied 8 months ago.

Can you conform your doing the battery draw test like the Ford link below shows?

https://dl.dropboxusercontent.com/u/90220402/draintest.pdf

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On your screen you should see a rating 1-5 stars. Please make sure to select one. I am not compensated by the website unless a customer rates. Rating only pays me from the deposit you have already made, it does not charge you more, nor close the post. Also all follow ups are free and welcome.

Thanks Chris

Customer: replied 8 months ago.
Pretty much just like that.
Expert:  Chris (aka- Moose) replied 8 months ago.

So after 40 minutes what is the draw with no fuses removed?

Customer: replied 8 months ago.
4.2 amps
Expert:  Chris (aka- Moose) replied 8 months ago.

Thanks, ***** ***** remove the fuses one by one leaving each out is there a fuse that gets the draw at or below 50 mA?

Customer: replied 8 months ago.
Fuse 53, run/start PCM
Customer: replied 8 months ago.
Is someone else available that can help me diagnose this?
Expert:  Chris (aka- Moose) replied 8 months ago.

I doubt there is anyone else wanting to help on this concern, since one tech has opted out already and you had to wait 4 hours for another tech willing to try. Though all posts are always open and anyone could take over.

I log in give or take around 3pm central daily like I mentioned in my first contact. I do not work on here in the morning when you are responding.

Fuse 52-53-54 are all on the same circuit so each would have a draw on them, is that what you got?

This fuse is powered but the run start relay, does removing that fuse stop the draw?

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On your screen you should see a rating 1-5 stars. Please make sure to select one. I am not compensated by the website unless a customer rates. Rating only pays me from the deposit you have already made, it does not charge you more, nor close the post. Also all follow ups are free and welcome.

Thanks Chris

Customer: replied 8 months ago.
Sorry for sounding upset. It's just starting to really get frustrating. So today I retested the parasitic draw test. Waited the full 50 minutes before pulling fuses. 4.2 amps of current. Pulled fuses one by one noting current on my meter. Pulled fuse 18 in the BCM. Current dropped to 1.2 amps then after a few minutes dropped to 20mA. Reinserted fuses current stayed 20mA. Put my large gauge wire back on the negative post to connector so I could turn the key to on for a few seconds. Turned key off and removed large gauge wire after lights went out. I have the door switches engaged so the PCM thinks they are shut. Waited 50 minutes still 4.2 amps. Opened up the BJB and started removing fuses one at a time. Fuses 52 and 54 do not drop the current. 53 did. Also while waiting the feedback noise got rather loud. I jumped under the truck and I could hear little pop noises coming from the transmission pan area. I unplugged the O2 sensor connectors, noises still there. I unplugged C1575, the transmission 16 pin circular thread on connector and the noises and feedback sound went away. I also heard the PCM relay in the BJB open. Got out from under the truck and my current was at 400mA. Waited for 2 minutes and current dropped to 20mA. A slight amount of water was in the trans connector. I'm going to blow dry it out and put some dielectric grease in the pin holes and test again. I'll have to test tomorrow due to my battery being at only 10.8 VDC. I've got the battery on trickle charge
Expert:  Chris (aka- Moose) replied 8 months ago.

Can you get the battery charged and see if fuse 53 has power with everything connected. This fuse should not even be powered key off, thus it should not be able to cause a draw.

Customer: replied 8 months ago.
I will and post the results. Is it possible that the Wisconsin winter salt could short between the comm pin and ground and cause the PCM to stay "awake"?
Expert:  Chris (aka- Moose) replied 8 months ago.

Corrosion and water intrusion can be to blame for many wire and connector issues, so yes that is possible.

Customer: replied 8 months ago.
my parasitic battery draw still exists. The noises last night were probably due to voltage dropping so low. Fuses 52, 53, and 54 all have 2.3 VDC on them. So something is back feeding.
Customer: replied 8 months ago.
I've unplugged the transmission connector c1575 and the feedback noise stopped and my current draw dropped to 2.2 amps
Customer: replied 8 months ago.
Fuses 53,53,and 54 still have 2.3VDC on them.
Customer: replied 8 months ago.
I took the alternator out. Performing parasitic draw test now. With alternator out and transmission plugged in 3.9 amps of current draw and humming noise back. Looks like something internal on the PCM is holding the stay alive power after key off engine off. The PCM has not had a reflash since 2011. Any chance there is updates that could solve this with a reflash?
Customer: replied 8 months ago.
if I remove F75, F53, or F18 the feedback noise goes away and so does the parasitic draw.
Customer: replied 8 months ago.
Now I pulled connector c2280F out of the BCM. Feedback hum and parasitic draw remained for about 2 minutes. Headlights flashed, him and draw gone.
Customer: replied 8 months ago.
it would make sense that the field effect transistor (FET) in the BCM on circuit F18 is not changing state at loss of excitation when the BCM times out and signals sleep mode.
Expert:  Chris (aka- Moose) replied 8 months ago.

If you remove the run/start relay under the hood does power on fuse 53 go away?

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