Electrical problems

Beastie93

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Rugby
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Ford Fiesta Titanium 2015
#1
Hi, I'm new to the forum, and I am seeking some advice.

My 2015 Ford Fiesta Titanium has today shown some concerning issues.

I got in the car to pop out to the supermarket and instantly noticed the Air bag warning light was on on the dashboard. Odd I thought... never seen it before. Didn't think about it too much until I started driving, and noticed that I no longer could flick through the features on the dashboard, and when I got to mileage it was showing in km and not miles. I could not change this. Also, i could not change anything on my radio, and my demisters did not come on either. The window controls have switched round (passenger switch operates drivers etc). After some further inspection the indicators on the mirrors do not work, the mirrors can not be adjusted and most concerning of all, I cannot lock the vehicle. Even with the manual key.

Any suggestions? Is this a battery issue? Does the ECU need replacing? Car does still start with no problems which something

Short term all I want to be able to do is lock my car until I can get this looked at.

Any help would be appreciated.

Dan
 
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'17 ST
#2
Check your voltage. The battery may start the car, but it may be weak. The electronics are fussy when they're not getting the correct power. My bet is a new battery will get it working right.
 
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Beastie93

New Member
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Ford Fiesta Titanium 2015
Thread Starter #3
Check your voltage. The battery may start the car, but it may be weak. The electronics are fussy when they're not getting the correct power. My bet is a new battery will get it working right.
Thanks for your reply. The voltage is at around 144/145 while running.
 
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City
Northern
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CA
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2015 Fiesta SE HB Magnetic
#5
Battery more than likely; but check/clean your main grounds first. It's amazing nowadays how a battery with just a minor issue with amps can mess with all the electronics.
 
Messages
104
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59
City
Grand Rapids
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MI
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United States
What I Drive
2019 Ford Fiesta SE HB
#6
Prepare to...

Roll up Sleeves...
Get some Baking Soda...
Toothbrush - or small Wire brush...
Elbow Grease...

Begin to take / Remove - the Battery Tray, It's cables, wire ground and even the PCM - using

10mm Socket - Ground Cable, Battery Cable main post, Battery cross bar holder (Deep socket works best)...
12mm Socket/Wrench for main LUG to Positive Battery post - that "RED" buss terminal...
8mm and 7mm as needed for PCM to loosen and swing it away...
Long 6" or 8" or 12" extension to fit your socket set you're using...
TORX 27 External "star" tool to remove the Drivers side Headlamp...
TORX "Star" set to help remove Airbox top even it's main assembly as needed to obtain clearance...
Phillips #2 to help with removing Fasteners that are not using TORX heads
Long reach thin blade Standard Screwdriver - to pry off trim and holders to obtain access to BUSS wiring
Battery Post/Terminal cleaner...

Start cleaning
1610576124608.png

Best to remove the Cable entirely and inspect it and the mounts make sure they are clean and not eroded...


PCM - Removal (CAREFULLY HERE...)
1610584076572.png

The biggest of the job, is to get the Battery and it's tray outta' there so you can get at, and get room for, the work and cleaning that may need to be done. Rusted bolts are no fun, but the sooner this job is completed and put back together, your efforts in costs of doing this job will be rewarded by not just the satisfaction of doing this yourself, but learning how this is all put together on top of the less problems you'll encounter with this electrical scenario later - you won't be bothered by or be sorry for, the work you did to protect your investment here...

The Main "battery ground Lug" to the engine was, (on-mine) - located under the battery tray between Main Block and Transaxle...

It's "lug" (Battery) to Frame - located UNDER battery Tray, on Engines Compartments (to the Inside on Frame) Frame by Tranaxle Motor Mount under Tray.

Want some relief? Relocate that "frame" to Battery ground point.

One thing I do recommend - REMOVE THE DRIVERS SIDE HEADLIGHT - unclip it's harness, undo those 2 - #27 TORX bolts, and 1 Philips head plastic screw holder from the front cowl and grasp the headlamp and cradle it, then; in a lifting-up motion yank it up firmly but lift it carefully out - set it aside on some cloth to protect the lens and case - and so you can see more and have the room needed to do your cleanup.

Locate your Other Lug Battery Ground terminal at the Drivers Strut tower, (OEM) it too can become your "ground point" - BOTH Cables can be BOLTED together here at the STUD bolt where the Towers' Frame "tang?" can be SANDWICHED between both lugs with a bolt thru to hold and pass current thru both terminals and main vehicle Frame.

It's now protected from the leaking Acid that can occur when the battery "Boils" on hot days - or you wind up with leaks because it's tilted from you're forced to stop at weird parking angles or intersections - even traffic jams. These moments are rare but where leakage from the battery vents can collect and drip down onto the frame and cross member and your wiring harness and their ground points. The Ground cable can be rerouted to a new location where the Battery Cable Ground and the Engine to Frame ground can share the same "WELD-BUSS" point. This is at that Strut tower ABOVE all that mess.

I only had to undo the main Frame lug side, it uses a simple bolt threaded thru to a WELDED nut, it's nut on the inside of the frame and spot welds, so you already know you're borrowing time - so the sooner this rewire is done, the longer the battery, connections and your vehicle - will last. There is a side benefit to this effort as well, your wire runs and voltage drops are minimal when you connect all your grounds to one tie off. Simplifies the inspection and reduces the maintenance effort required to keep things clean.
  • In the above starting photo, you'll see where I soldered the wire cable to it's lug. I highly recommend this but not everyone is able to do this simple job...
  • You can get burned from using high heat and molten solder is not your friend. I had to use a mini-torch to heat the lug and allow the rosin core solder a means to flow onto and melt into the cable and fill in the gaps in the strands - it's takes effort and time and patience - but done right it's worth it.
  • Flux is used to not just clean, but also allow the solder to wet, and flow onto the copper "stranded wire" the #2 AWG cable is, this helps in waterproofing and reducing the chances of having a failed connection in both voltage drop and amperage pull from the seemingly minor ohmic drop - a lot of heat can be generated from simple engine cranking - that's the ohmic loss converting to heat
It's easy enough to resnake that engine ground cable thru, under the tray, PCM and around the harness - the main effort is to do this while you have the Battery, it's tray, PCM and all wiring - freed up from the confines of that battery and it's tray. What is nice here, is the review and cleaning - repositioning as needed - parts and harness covers braces, brackets and bolts along with a series of grommet push-plugs that are for the Airbox, Harness, Tray and PCM - you can easily go over these areas and clean them up and inspect for wear, damage and if needed what you'd be up agaisnt if the damamges in corrosion are too severe for simple cleaning and requires more of a rebuild repair

1610575850946.png

The Battery work you'll need to gain access to is located under the Battery and behind the Airbox.
1610577064330.png
Your main problem? May be at that BUSS point off the Positive Battery Cable side.

That section uses simple Lug to Spade tangs to hold their position.

There is very little to protect them from the elements so they may be corroded and causing your intermittent problem.

1610577398916.png
See that Red terminal block? It uses two bolts - one for the Battery post, the other is a steel chrome plated "feeder" system that - after going thru the Fusible link - breaks out into a BUSS system of contacts using Bolts to hold lugs and or spaded terminals.

When you undo the 12mm nut, the Buss and the Battery terminal separate into two pieces, one for the Battery post, the other is to those various wires that; for two of them; one is for your Starter and the other is from your Alternator.

There are other less hefty terminals off of this BUSS that are branches to provide power for various systems - like; Engine compartment Fuse Block, Passenger Compartment Fuse Block and other systems bolted to the vehicle in one place or another.

When you lose good connection or have corrosion at these connections - their lifetime to support the current draw and provide the least level of voltage drop - becomes limited - shorter. Terminals use metals - that are conductive when they are refined, but when they are in their reduced state of ore, are more like insulators - don't conduct power as efficiently as when they are refined.

Mother Nature Abhors A Vacuum - (ST - Spock)​
1610590274371.png
So once the metal loses it's "ore" and obtains Conductive, Conducive status - nature is already at work finding ways to reduce it back into it's original form. This is corrosion it is a process of REDUCTION - so it simply uses the Oxygen that is always present - and the efforts of moisture, salt, dust, dirt and road film and its' toxins - added together form a methodology that when a trickle power of voltage and current is placed across it - accelerates its reduction, an Electrolytic as well as a Galvanic action takes place.

This is where your problem may be occurring, past the battery, but in the BUSS transfer system that takes all the current and breaks it out into a set of wires piping that power to places that Ford fits - where they see fit - to fit them.

So, when life deals you a "Lemon" - make Lemonade!
 
Last edited:

scotman

Senior Member
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Grass Lake
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#8
I firmly believe that electrical issues will soon eclipse most all mechanical issues. Including the DPS6 dual clutch transmission.
Battery condition and clean terminals and ground points, including the ones under the seats are absolutely paramount.
I also like to apply a petroleum jelly (aka Vaseline) after I clean and reconnect the ground connections. That stuff is the perfect combination of highly effective and dirt cheap to stop corrosion dead.
So many of the controllers and relays are VERY sensitive to drops or spikes. It's not that they need steady supply of high voltage. They live on very, very minute values that must be reliable. When the battery voltage drops due to cranking demand or even something as innocuous as cranking up the heater blower and then tapping the rear defroster on Could cause a systemic power crisis. That is when the canbus communication failures will fill the whole laptop screen.
 

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