C1175, C1297, C1222, C1296: Replacing rear wheel ABS sensor

Entrapment.  My top fear, right after heights and too thick (or thin, for that matter) a glaze on my creme brulee.  No matter what I do to ensure my car is properly lifted and secured, there's a nagging fear in my head my repair work will end tragically, where my last sight is the under-body of a Ford Freestyle before my demise; at least I will have the happiest widow in the tri-county area.

Lifting the rear of the Freestyle requires more forethought, because there's not a good lift point aft of the front door where I can fit a jack and then a jack stand to bear the weight while I'm working.  To lift the car, I jacked the front enough to lift the rear tire off of the ground and then placed a jack stand at the rear of the car on the unibody rails where one would put a scissor jack whilst doing a road-side tire swap-out.

Once the wheel was off, the sensor was nicely exposed and I had (just!) enough clearance to do what I needed to be done.

C1175, C1297, C1222, C1296: Traction control sensors; the beginning

Not that RCA.

Root cause.  The next few posts will be about root cause analysis disguised as automobile repair. Properly doing an RCA means identifying the problem, understanding it well and then fixing it.

For those in engineering fields, RCA, root cause analysis, has deep office-politics ramifications: doing an RCA for most below average engineering groups (half of the engineering groups fall below the average!) means somebody will be blamed for things not working at at risk of losing a chunk of their annual bonus.  Fingers will get pointed.  And people will scurry to avoid the RCA fickle finger of fate.  All of this is too bad, because when we learn the root cause of something, it presents the easiest way to fix the problem with the most certainty the same issue won't return.  Turns out, the real world is a bit more messy.

P0171 and P0174, solved!

The CEL started to glow and the resulting error codes were P0171 and P0174 both mean that the engine is running lean, which means too much air and not enough gas.

Not being sure what the problem was, and starting with the "not enough gas" theory because, well, that just seemed a good place to start.  Up went the hood and the problem became a bit more obvious

The line from the brake booster, which is powered by the suction of the engine as it's taking in air (an engine behaves as an air pump) became disconnected and that resulted in more air making it past the throttle than the engine management system expected. 

Here's what things look like after proper assembly

Eighteen seconds later and my repair was finished.  Not having my phone handy, I used my old-timey OBD scanner tool to read the codes and then clear them from the system

The codes didn't return after 100 or so miles, so this was definitely the problem.  In anticipation of the problem being the fuel filter, I have a new one of those on hand, I'll post when I get to replacing the existing filter which appears to be old and in need of swapping with a new one.

P0171 and P0174

After a few weeks of smooth running, I see the check engine light, I thought it was the fuel cap not tightened.  Fired-up Torque and the codes P0171 and P0174 came forth from the engine management system.

P0171/P0174 means the fuel/air mixture is too lean.  That means a) too much air b) not enough fuel c) some combination of a and b or d) a defective sensor.

Air?

In the case of d, we'd be looking at the mass air sensor, but let's assume our sensor's telling us the truth and we're not getting enough gas or too much air.  Let's start with the air: I checked under the hood and the path from the filter to the throttle looked OK.  That leaves the intake manifold seals.  Not sure how old those are, could be the culprit.  Alldatadiy recommends that I also check the EGR system as well, that seemed to be OK.

Gas?

Next the gas: No leaks.  The filter (sorry, no picture!) appears to be old -- could even be original.  The fuel pump might not be moving the fuel to the I'd start with replacing the fuel filter and see if that helps.  But first, I'll clear the code.  If the code appears again, I'll know it's not just a ghost in the machine.

Environment? 

It must might be the unseasonable temps and the huge dip in temperature the last few days.  Here's last week weather thanks to timeandate

Maybe there was some condensation where there shouldn't have been with the quick dip in temps.  Or couplings cooled at different rates, allowing for some leakage. If the code doesn't come back, I'd attribute it to the sudden shift in weather; but, I think that's wishful thinking and something will need to be fixed in the near future.

Limp Home U0101 et al...

Just doing my errands, heading home from the grocery store and what do I see but the return of the wrench and engine lights along with the RPMs leaping as the engine decides that limping home is the best way home. Fortunately, we were just a few miles from casa del 500 dinero coche, on roads where the top practical speed stays below 35MPH, so no biggie.  Can't say my passengers were all that happy, even though the car performs well most of the time, they expect to be stranded for every outing.

I was able to get the codes from the car using the Android “FordSys” program (more on that later), here’s what I have:

Code	Meaning
U0101	Lost communication with TCM (transmission control module)
P0641	Sensor reference voltage ‘A’ circuit open
U0415	Invalid data received from ABS (anti-lock braking system) module
U1900	No description
B1318	Battery voltage low
B1342	Electronic control unit is faulted

After letting things rest (and the super-cap drain so things reset), the engine started no problem, no wrench light and the check engine light turned off after the second engine running cycle, just like the last time this problem occurred.

Sometime a few months ago, I broke down and laid-out the $29, or something like that, for an AllData DIY subscription for the Freestyle. For the error codes in question, there’s a bunch of “pin point” tests to check for continuity and wiggle checks for the connectors.  What All Data doesn't provide the full schematics for the car, as I'd like to see where +5v circuit A goes, as I have an intermittent issue with some segment of that wiring it seems.

Looking at the codes above, I’m guessing a short or disconnect (somewhere?) resulted in a few components going into reset due to a voltage drop or the networking between the components failed due to signal integrity. Before replacing parts, I need to make sure the communication between said parts works properly, or I won't be fixing the problem by swapping what's at either end of a bad connection.  I’m presently replacing the brake lines on my kid’s Grand Am, so the actual checking will need to wait for a bit.

FordSys

All of the diagnostic information comes to me complements a program on my Android phone called FordSys. A regular code-checking program returns no problem codes, because what’s reported above aren’t in the standard inventory of codes for engine trouble a generic code reader reads. I very much like FordSys, I’m not so crazy about the intrusiveness of the ads.What was small ads on the bottom of the screen has morphed into full screen overlay ads. I’d much rather pay the developer, who deserves the money for his hard work, and not be bothered with ads at all.

Christmas tree and a trip to the mall

We went to our local tree farm (being out in the country, there are several tree farms to pick from) to slay our Christmas tree.  The "product" of a fresh-cut tree involves climbing on a tractor, being abandoned in a field with a saw and hauling the tree home atop one's car after the tree has been baled. Wondering around in the field looking for a tree means that quite quickly, nearly all trees begin to look the same.  Only once it's home does one notice the bald spots and general crookedness of a tree that looked just fine in the field.  Buying a used car is pretty much the same experience, what looks to be great in the lot with its companions seems to loose its luster once you've gotten it home. Buyer's remorse?  Maybe it's just too difficult to process so much information at one go, so our brain fills in the details, dents and scrapes.  When we're looking at one car, we can the concentrate on the finer details.

Probably won't fall off, maybe?

 We didn't always go Christmas tree hunting, in our family, BC (Before Children, or, BCE, Before Children Existed for the folks with a knot in their kickers and variously colored hair.), we celebrated Christmas sans a tree. Having a $500 dollar car means not having to worry about dents/scratches incidental to getting the tree home, all one needs to do is heave the tree on the roof and secure it with some twine.  No padding or a tarp, just get close and lob.  It wasn't always like this, when we drove an overpriced Honda SUV or pricey minivan, we cared about the roof.  Dents?  Scratches?  Sap? Mud? All of that used to matter when our car monthly payment approximated the purchase price of the Freestyle.

One feature of the Freestule that I just love is the raised roof rack.  This made securing the tree much easier, as I had an easy place on which to loop the twine and make knots.   In the process poorly securing the tree to the car, I looked down and what did I see by an expended hypodermic needle.  It's probably flotsam from a friendly neighborhood injectable drug user, either getting their tree or working in the fields.  Maybe a diabetic?  Most diabetics fanatically keep their sharps safe, so maybe, but unlikely.

A trip to the mall, some more Christmas lights

Limp home mode

The next day, we got the first snow of the year: better than a light dusting, maybe one or two inches. On my way to the mall, after dropping my kid off at work who didn't want to drive in the snow I felt the AWD system kick-in and then my troubles started.  The car went into "limp-home mode".  An Eat 'n Park was close by, so we stopped there for brunch and after eating we'd see if the problem went away, as stopping for a quick road-side reboot of the engine didn't help.  I didn't have my code reader handy, I'm not sure what problem occurred, but we got the combination wrench and check engine lights, as the picture shows.  This can mean either transmission, transfer case or throttle problems.

Former furniture store

Post breakfast, the engine started without an issue.  We needed to head to the mall for some shopping, which was close. If the car became cranky again, the plan was  to have the better half shop while I called for a tow.  I'd have a nice place to wait at the mall for a tow truck and would return to the mall with a working car.
My last visit to the mall was... I can't even recall when I was last at the mall, but over the years, there's been a shift from retail to personal services.  Now, however, the transition now seems to be from personal services to just empty spaces, not unlike the transition many small town's main streets in the area endured in the 1970's as retail fled main street for the mall, store fronts turned into exercise and tattoo parlors before the front windows served to hold news paper concealing the empty insides.

Earlier this year, before the retail season, Sears closed at the mall.  When the Beaver Valley Mall opened in 1970, Sears was an anchor tenant (along with Gimbels and Horne's), maintaining the same location for 40+ years: a dependable source of tools, lawnmowers,

As always, an empty lot around Sears

boots, Levi's and something polyester your grandmother would wear to a cousin's wedding.  The next biggest tenant, Macy's, doesn't look to be sticking around, as the upper floor has been closed and the range of merchandise greatly decreased.  Meanwhile, across the street, Wal-Mart's lot brimmed with shoppers.