Ford Focus BCM and the Technician BS Meter
A few weeks back I was asked by a shop to program a replacement BCM for a Ford Focus. Due to software hiccups, I was not able to get the IDS software to work so I used IO Terminal instead. After installation the BCM worked perfectly. Key fobs working, keys working, door locks, ect… My job was done and I went on to the next one. Then last week I get a call to the same shop on the same Ford Focus. It seems that the just replaced BCM failed. WTH?
This next part I have to give credit to Richard at Extreme Auto Service in Centerville, UT. Previous to my arrival to program second BCM he had researched high and low on the internet and came up with the reason why the BCM failed so quickly. This is where the BS meter would have normally pegged. Remember the Jeep Grand Cherokee that would eat rear O2 sensors on a regular basis? The reason for the Jeep was a leaky PS pressure sensor. It would wick oil all the way through the loom to the O2 sensor. The O2 sensor relied on getting it's comparative O2 supply through the gaps between the strands of wire instead of a vent in the O2 itself. Pretty wild, yes?
This solution is not as wild but very close. It seems that the windshield washer pump on these Focus models fail in a very similar way. The fluid pushes through the wires and back to the BCM where it dumps into the BCM contacts. POP GOES THE WEASEL and now the BCM is again toast. I was told when the technician removed the now faulty BCM, washer fluid came out. I would imagine this would be difficult to figure out during the summer when this connection dries out. It was obvious with the first BCM moisture was getting in. We all assumed it was condensate from the A/C or a windshield leak. Pretty far out there to be washer fluid. The fix was to overlay new wires to the BCM, Replace windshield washer pump and replace the pigtail again. Of course a replacement BCM was needed. Programmed it up and we are good to go!
This is very good to know, thank you for your time. I thought I had heard something on this before. I try to read all of your posts.
The washer fluid in the BCM is pretty wild. Who would even guess at the connection?
Wow, will need to stick that in the back of my mind for when I see a failed BCM. Any pressure sensor or a washer pump. Thanks for sh….
Definitely gonna keep that one in the back of my mind. Was there any evidence that the washer pump had been replaced with aftermarket previously? Or was this a problem with the factory pump?
Tyler, I replace these BCMs all the time with the blue/green color in the connector. I always assumed it was the copper oxidation but now wondering if it is the blue dye in the washer fluid. Since I see it so often I would say that it is an OEM issue.
Wow, sounds like a bulletin is in order. Hope Ford reads ALL your posts, just like I do. Happy New Year Mike.
Land Rover had a similar problem where an oil or power steering leak would drip onto a wire and inside the casing causing electrical problems.
Hi Mike. Catching failures such as those are always interesting and never forgotten! An enjoyable read and thanks for sharing. I experienced something similar circa 1998, was on a Chevy Blazer or 1997 vintage. The tech in the next bay had handed a warranty R.O. back in after “No Fault Found” conclusion as to why the A/C wasn't cooling intermittently, but when it worked it worked well. In…
Martin, That is pretty incredible! That is a great story. I am so glad you figured it out before something started on fire. Wins like that need to be recorded. You touched on something that is a systemic problem in the industry, The labor allowance of .3 hours is hardly enough to drive in from the parking lot. Then the OE expects the technician to figure out a strange and unusual problem within…
Very interesting,thanks for sharing
A common problem in the UK unfortunately SY Diagnostics does some good case studies on Euro Fords and VW group m.youtube.com/watch?v=aJigtE…
Thanks Michael, also very common for passengers in the front left seat to kick the BCM plugs loose on our version of the Focus!!!!
The white colored BCM makes the color easier to see. We do have a few with White cases but most I see are Black cases. Now I need to call all the shops I programmed these for and explain the defect so they can make their customers aware of the issue.
Another great post Michael! Readers should also be aware that due to the way Ford wired this circuit, a significant parasitic draw can/will also result. Turns out, Ford uses 2 relays in the box to control the voltage to the pump. In concert the 2 relays will apply power and ground to make the pump turn in one direction for front squirt and the same load wires are reversed by the relays to turn…