TCM Fault Light Diagnosed As Not Needing New TCM

2014 Focus SE, PowerShift, 60k miles

Here is what has flashed on our dashboard within the past couple weeks:

— Battery light
— Hill assist not available
— Transmission fault, service now

Service rep from dealership noted that the battery light could possibly be going off due to corrosion on one of the battery cables seated below the battery enclosure. We were there for the latch recall as well as to replace a dead radiator fan. Fixed the fan, and we were told that the corrosion could be cleaned off with hot water but not really noted at the time as a big problem. At this point in time, only the battery light was flashing when diagnosing the fan problem at dealer appointment #1.

Cut to a couple weeks later. Next event was the hill assist warning coupled with the faulting transmission warning. These went off while driving back to the house from a nearby park. While leaving the parking spot I noticed the steering was extremely stiff, basically locked in place, it took a couple seconds for it to loosen up, then the two warnings flash on screen. Called dealership next day, learned about the huge backorder on TCMs. Called the two other nearby Ford dealers, found one with least number of Focus's waiting for new TCMs.

Towed Focus to dealer appointment #2, waited for call back with the news that we're gonna need a new TCM. Got the call, turns out we won't need a new TCM, nor clutch. The problem was diagnosed as having to do with our battery system causing the fault in the TCM, they noted the battery cable corrosion as a secondary issue but that the main service needed was:

"BATTERY MONITOR SENSOR, WIRING JUMPER HARNESS TO ACTIVE SHUDDER GRILL, AND CONNECTOR TO GRILL HARNESS (CONNECTOR 1651 3 PIN 3U2Z-14S411-NPA)"

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That is the exact line item quoted from our estimate. Do y’all have any relatable info that would help me understand why fixing these three things will have us good to go, without having to replace the TCM (at least for the time being)? I’m glad we won't be waiting months and months for a new TCM, but this is one of those situations where I'm mostly listening to the dealer without really understanding what they're saying. Thank you!

A bad battery connection can cause all sorts of electrical gremlins. Some systems in the car will get wonky when they don't receive the proper voltage especially those that connect to the PCM or any other module with a computer in the car. Your trans and hill assist which I believe is linked to the ABS/brake system would be dependent on a computer. The EPAS(electric power assisted steering) stopped working temporarily as well which is also computer dependent.
However, the dealer apparently determined that the BMS(battery monitor system) was the cause of the electrical issues. From my understanding the BMS regulates power to various systems and accessories in the car based off the current that it monitors from the battery. To preserve a stabile system wide current it may cut power to accessory powered devices.
The BMS sensor is what they think needs to be swapped to fix it.
The dealer apparently also determined that your grill shudder system wasn't working properly and those are the wiring parts to fix it. I believe cooling related issues are attributed to it and you did say that the radiator fan wasn't working before.

Cobrajet, I really appreciate the follow up—it helped out.

I wanted to go ahead and just put an update here in this thread instead of creating a new one, for sake of continuity. I ended up OK’ing the new BMS, as well as the wiring jumper harness and connector for the grill. It has sort of led to a pretty stressful/drawn out back and forth with the dealer so I’m hoping I can get some straight forward feedback here.

A quick refresh—their service recommendation of a new BMS was what they diagnosed as the solution for clearing out the trans fault light, the battery light, as well as the hill assist not avail+ABS light+traction light. We OK’d the service and received the call it was time to go pick up. We pay the costs before the car is brought around, are given the key, hop in the car and the hill assist light immediately pops up along with the same cluster of ABS, traction, and now the brake light. The brake light was new.

We go back inside to tell them the alerts that weren’t cleared out. My service advisor had already left for the day so we leave the key with the folks up front and we go back home, slightly confused, fairly pissed. I called and emailed service advisor the next day, but didn’t receive an update until the next business day after that—the following Monday.

She replied to the email, attached an estimate PDF, which is clearly just the same estimate from before except it’s been amended with two new line items: “EHCU” for $2k, and a suggestion for a new motor mount. The additional EHCU line item is scarce on details, that is the entirety of what is typed. No part #, no labor breakdown. She explains in the email that the car was “driven and cleared of codes before it was released”—yikes. I took note of what the milage was when I sat in the drivers seat after paying for the BMS service, there was no change in milage from when we originally dropped it off. She then goes on to explain in the email that the service tech is saying that “we now have codes for the EHCU, which is part of your ABS system … here’s an updated estimate.”

I took a couple hours to figure out how to follow up, and we decided to just reach directly out to the service manager. My first call with him was just me explaining who I am, our car, and an order of the events so far. He said that he needed to go talk to the service tech, look into this, and get back to me. I waited til EOD to reach back out and see what he thinks but got his voicemail, so I just left a brief message saying that I’m following up on our convo from earlier and to call me back.

The next morning I woke up to a really early voicemail from my service advisor saying that she’s returning my call from yesterday (?). I decided to just go ahead and email the manager my thoughts on the situation. Explaining how the first work order was written up in a way that shows their service recommendation for the dash alerts was to swap out the BMS and the two shudder grill parts. That we took time off to uber out there, pay for the service, to then see the same hill assist and ABS alerts. How it took them a month to do this BMS swap out. How I’m now beginning to get pretty uncomfortable with any sort of piecemeal approach to finding a fix for this car. And finally how I now feel pretty much stuck and “locked in” to this situation they’ve created where I’ve already put X amount of money into fixing the BMS, but now to get the car fully on the road I’ll need to pay an additional $2k. My original thinking, which I talked to the service advisor about when we first dropped off the car, was that I’m worried the fixes to the car would far outweigh what the Focus is even worth at this point. If I had seen a full diagnosis from the start, with everything laid out, I could have very well made the decision to trade it in and move on. But since I’ve already paid into the original diagnosis, I’m not really in a position to make that type of decision anymore. This was all explained in my email to the service manager.

He calls me pretty quickly after I sent the email, and we have a fairly constructive convo, without dramatic emotions, so that was nice. He explains that the service advisor was mistaken. The car was never supposed to be labeled for pick up. After making his BMS diagnosis, the electronics tech was supposed to hand off the car to the brake specialist for additional service recommendations. My service advisor apparently fumbled this hand off, then sent me an estimate containing only the electronic tech’s recommendations. I explained that I decided to stop going to my Ford dealer that’s right down the street due to a lack of communication and that I was really hoping this new dealer, that is much further away, would turn out better. The manager explained this is not how they normally run their service dept and reiterated that there was a miscommunication on part of my advisor. He asked if we had transportation throughout this past month and I said no, we don’t, and that we were originally told there are zero loaners avail right now. He ended the convo saying again, that he’s going to go talk to the tech and figure out the next steps.

He emails the next day with new numbers, he brought the $2k EHCU down to $1,500 and explained that $1k of it is for the part, assembly, and labor. Then the remaining $500 is for the reprogram. He apologized again for the confusion and said he’ll give us a rental. He explained that since the electrical was fixed, the tech was able to pinpoint the issue to the EHCU for the brake system.

Now on a personal note, myself and my team @ work were laid off recently, so I’m pretty deep in the job finding routine. I am super thin on my patience with this car and spending any more time wading through all this. Though I still feel the way I do about the situation, I’d rather OK the service to get the car back and move on. My spouse is of the mindset that we should probably part ways with the dealer, and find a mechanic that can second this service recommendation and possibly quote a cheaper estimate. But obv that includes us doing further research for a competent mechanic, towing the car there, waiting for diag, etc etc.

My previous car was a 2000 Jeep Cherokee, so this is our first car that contains chips, computers, programming, etc. Is the general consensus to leave all those problems for the dealers to fix? We live in a major city in the south, do these dealer #’s seem in-range for you all? How would you move forward with this situation?

Thanks in advance for your time.

Also, your 2000 Jeep had modules and computers(both have chips in them) that have software and need programming. You just didn't have any problems with them.

Alright, thanks Cobrajet. Please continue with the bluntness (it helps) but let me clarify that the service on the BMS did clear out the trans fault light, as well as battery light. This was the work diagnosed by tech #1 (electrical).

The problem was that instead of handing the car off to tech #2 for further diagnostics, my advisor went ahead and wrote up an estimate, emailed it to me, and I approved it. This led to essentially a half-cooked estimate, where only half of what was supposed to be recommended, was recommended. And of course this then leads to the advisor saying "car is ready", when it wasn't.

So that leaves us with the still-currently flashing dash light cluster of: ABS, traction, and brake, with the hill assist pop-up notification. Tech #2 has since relayed a code to my advisor, who has emailed it to me: U0300-51.

Definition:
Internal Control Module Software Incompatibility: Not Programmed

Failure Type:
Not Programmed
This sub type is used by the control module to indicate that programming is required.

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I've also found a PDF that notes U0300:51 with reference to the ABS system (page 13)

U0300:51

Internal Control Module Software Incompatibility: Not Programmed

Action:
— CHECK vehicle service history for recent service actions related to the
ABS module. This DTC sets due to incomplete or improper flash
programming procedures.

— If there have been recent service actions with the ABS module, REPEAT
the programming procedure as directed by the diagnostic scan tool.

—If there have been no recent service actions, INSTALL a new ABS module
and HCU assembly.

REFER to: Hydraulic Control Unit (HCU) (206-09 Anti-Lock Brake System
(ABS) and Stability Control, Removal and Installation).

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Two more things—it's been clarified that the $500 is for labor and programming, while the $1000 is for the parts (healthy mark ups aside...). As far as I can tell, "EHCU" seems to be some kind of in-house term the dealer is using when referring to the entire HCU/ABS module assembly. So, HCU + ECU = EHCU? I don't know... But knowing the correct term has actually allowed me to pull up old threads here to confirm other folks talking about how Ford prefers to service the entire assembly when they find a problem with either portion.

neal cassady said:

Two more things—it's been clarified that the $500 is for labor and programming

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I see. This now changes things from what I said before. $500 labor for installation and programming makes more sense.

Yes, I think they added an extra E when they shouldn't have. Ford names the part without any E for electronic, it's just HCU. The service tech just confused things by doing that.

I believe the HCU and pump are now only sold as 1 unit. They used to be available separately but no more apparently.

I'm betting the BMS did something to your HCU but idk that for sure. For that to happen at the same time is unusual. In any case, my first assessment of your Ford dealer may have been incorrect since I only had partial information. They may not be total thieves and liars but are at least a bit incompetent, at least that service advisor is.

I'd still call around and ask another dealer to price out the cost and labor for replacing the HCU/pump assembly. It's probably not going to be all that much cheaper though. If the software in it is corrupted then I think you have to go to a Ford dealer to have them retrieve it from their system idk.