FFHinVA

I think using the extension wand/tube is pretty critical to covering all surfaces. The fluid is sprayed 360 degrees out from the tip, perpendicular to the tube. You push the tube back in as far as able and slowly withdrawal, going forward and aft. I think that pretty much gives you full coverage. But something is definitely better than nothing.

I don't have a sunroof (and thus no drains), so I can rule that out as a water entry point for my rocker panel rust issue.

WD-40 is a good temporary fix. But it isn't a thick coating that will cling to vertical surfaces, and it eventually dries off. I would Google "Rocker panel internal rust proofing" or similar words to get an idea of what everyone is using. You don't need to coat and paint it. Just coat it. You also need a long tube(3' or so) or wand to coat the entire internal area. I've been all over the internet looking into this. The Fluid Film with the long extension tube, seems to be the best (based on cost, application ease, and effectiveness) by my research. I bought this on Amazon: Fluid Film 11.75 oz. Spray 3-Pak, Spray can Extension Wand. It's enough to do both sides. Just push the tube in as far as it can go in all directions and then spray, and pull the tube slowly out (mark the hose with a marker so that you know when you are getting close to pulling out completely).

Concerning the hole left from the air deflector, I had same concern. I used a piece of waterproof rubber tape (T-Rex or Gorilla?) to cover the hole, but then inserted a plastic tube (ink pen part maybe?) at an angle down, and pointing aft. If water did accumulate it could drain out. Note that there are also drains in the crimped metal seam used for jacking. (See the white spot on side view pic. Although I guess they didn't work so well.) This was installed back in March (2021) and is still holding up. The debris inside the tube is the Fluid Film.

Inner wheel well panel is easily removed. Need to take wheel off first. See the diagram on my 23 March 2021 post for attachment points. Looking at Robinsone pics above, I didn't have the extreme amount of debris behind the cover, nor did my welds look bad. There could be multiple water entry points. As far as an inside preservative, there's a whole slew of fluids tried and compared on YouTube. To me, Fluid Film seemed to be the best (thin enough to spray and flow, but sticks), and most easily obtained. There is a new PB Blaster product that is also good, maybe the best. Check out "I Finally Found The Best Undercoating On The Market... Blaster Surface Shield" by Repair Geek. This guy is thorough, logical, and articulate. But, he is focusing on exposed surfaces. Inside the Fusion rocker panel is a somewhat protected environment, except for the humidity.

That may hopefully be the case, IE its road salt related, and not purely due to water intrusion. But, moisture being trapped anywhere will eventually be a problem. Salt just accelerates the corrosion. But, in any case, when this happens, it seems to happen very quickly. And it's not very noticeable because its way low on the rocker panel underneath the undercoating. The undercoating works as a structural surface or glue of sorts that keeps it all together even though its rusted through. (So, it may look ok today, but next month who knows.) I noticed when I wash my car (or if it was raining), that the water runs down the side, and wraps underneath down to the air deflector, and then flows underneath into where the air deflector is attached. So, water is being trapped or obstructed by the plastic piece, and it might just be a lot of water hitting that one area where there is access to inside the rocker panel. You can pull the plastic piece off and look inside the hole with a borescope for rust. (Borescopes are cheap, on Amazon.) Or have your local garage take a quick look. You can't really let it go, because although at first its cosmetic, it then becomes structural because that's a jack lift area.

This really needs to be a Ford TSB send out, or an "urgent rust alert" on this forum so that everyone will check their rocker panel in this area. And at least clean off the deflector (maybe). And... maybe remove the deflector completely, if that's the fix. Time is not on anyone's side. (Also wondering if road salt is the culprit. And not just moisture. Do any Florida, Arizona or Ca owners have the same issue?)

Maybe the rear "air deflector" (#11778 on diagram attached, PN 5411779) is catching all the debris from tire rotation (counterclockwise) and pumping it inside the rear rocker panel area? Maybe solution is to tape/caulk seam or lip inside wheel well where deflector sits on edge? Or maybe front edge of deflector is picking up thrown water and debris from front tire? Maybe just remove deflector altogether?

2010 Hybrid started having water bubbles on rocker panel just in front of driver side rear wheel. I slit open the bubbles and water came out. Painted undercoat peeled back. I pulled off the mudflap/deflector and trapped debris and sand came out. (Is the hole under the mudflap another drain hole?) (See 2 attached pics of bubbles on side, mudflap, and hole ) I started poking around and pushed through a thin section in the bottom. (see pic) I opened up the hole and looked inside with a borescope. Majority of rust scaling seems to be in the back (near wheel), not in the front. and heaviest on bottom and then moves up the side of the rocker panel. There are four drains located on the pinch weld, maybe one inch raised area each. One is right next to mudflap. There weren't clogged. I could see the plastic line I inserted from inside with the borescope. The drains though, don't drain the outer recessed section. There is maybe a 1/4" depression, couple inch wide (you can see from bottom) that could retain water. There should be drains or cleanout plugs in these lower sections. Note that the rocker panel seems to be a a cosmetic panel because there is a thicker beam inside. The beam and the rocker panel converge in the back into a very tight area that would not encourage drying if wet. Also, the road debris collected on the mud flap may be working it's way in. (Not sure I even understand the purpose of this mudflap. Others call it an air dam that routes the air around the tire. Maybe just remove it completely? Is this the source of the moisture?) There are two videos on You Tube: "2010 Ford Fusion rocker panel rust" (Really bad!) and "2011 Fusion leak fix? Stop the rust!". (Thinks water is getting in via the wheel well liner retainer-I don't think so). For my car, I'm trying to clean the scale out with a wire and fingers, and then I'm going to shoot Liquid Film (Amazon) into the cavity, and then close up the grinded out hole with a rubber plug. And then sand, repair, repaint outside. This defect in the design completely surprised me. If this was 1970, I would understand, but this shouldn't be occurring in a 2010 car.

Hybrid EV mode works again! Success at the dealer! Had similar lack of EV capability on my 2010 FFH (111K miles) that everyone is describing starting about a year ago. Tried everything including the battery rebalance at the dealer back in 2019. I also started having a "wrench" light and the "Stop Safely Now (SSN)" triangle occurring. I was going to try myself (via allen884 directions - And thanks to allen884 for taking the time to publish!) the battery clock set back, but needed a Windows10 laptop, got sidetracked, etc. , and didn't get around to it. (I did install the FORScan lite on my android phone, but this doesn't allow any changes to be made to the software). But then the urgency increased due to the SSN triangle. I also saw where the TSB 20-2142 (attached) came out in April 2020 to correct the EV issue. Also, TSB 11-7-31 was already out there since 2011 which addresses the wrench issue, and I wasn't sure if it was done on my car. And, interestingly enough, the dealer wasn't familiar with the TSB. Just thought the batteries were getting old. So I decided to get everything checked and hopefully done. In summary (For $262, 20Nov2020)… 5 modules were re-programmed: BECM, PCM, IPC, BCM,TCM Performed BMS reset and Adaptive Strategies reset. TSBs 11-7-31 and 20-2142 reviewed and applied/conducted (through re programs). And now I'm back to 42mpg in town, and can get up to 30-40 mph on electric again (within 20 mins of leaving the dealer). Also, I complained to Ford in 2019 about the EV loss, under case# 17514618, and I received no notification about the TSB being released. Nothing, at all. No wrenches or triangles yet either, but time will tell on those. TSB 20 2142 for reduced EV mode MC-10174404-0001.pdf

Hybrid EV mode works again! Success at the dealer! Had similar lack of EV capability on my 2010 FFH (111K miles) that everyone is describing starting about a year ago. Tried everything including the battery rebalance at the dealer back in 2019. I also started having a "wrench" light and the "Safely Stop Now(SSN)" triangle occurring. I was going to try (myself) the battery clock set back, but needed a laptop, got sidetracked, etc. , and didn't get around to it. (I did install the FORScan lite on my android phone, but this doesn't allow any changes to be made to the software). But then the urgency increased due to the SSN triangle. I also saw where the TSB 20-2142 came out in 2020 to correct the EV issue. Also, TSB 11-7-31 was already out there since 2011 which addresses the wrench issue, and I wasn't sure if it was done on my car. So decided to get everything checked and hopefully done. In summary (For $262)… 5 modules were re-programmed: BECM, PCM, IPC, BCM,TCM Performed BMS reset and Adaptive Strategies reset. TSBs 11-7-31 and 20-2142 reviewed and applied/conducted (through re programs). And now I'm back to 42mpg in town, and can get up to 30-40 mph on electric again (within 20 mins of leaving the dealer). No wrenches or triangles yet either, but time will tell on those.

I thought with the large hybrid battery, and the large electric motor, that a bad or failing 12V battery would not cause start issues. The 12V controls relays (from forum discussions) for the hybrid battery. If the 12V is failing everything shuts down. This seems to be a common topic on the FFH forums. Good insurance around here (Virginia) is to replace 12V batteries every 4 -5 years ( for all cars).

You are totally correct. My 2010 (bought at 64K, now at 104K miles) has always frightened me whenever I needed to merge into traffic. It's dangerously hesitant. It is the one primary issue that has caused me to maybe think about selling it. (And now I have the aging battery no EV mode issue - the 2nd major issue.) What is odd, is that if a Tesla can put down instantaneous torque at 0 rpm, why can't the FFH give me that (albeit, not as much)? I brought this issue up in an office conversation, and one of the younger guys said he had same problem in a Kia or Hyundai hybrid. A friend reprogrammed it, and it made a world of difference. Almost gave it a Tesla-like acceleration response. So, I'm going to look into reprogramming. There may be a downside, but the precedent has been set with Tesla. But also recognizing that the hybrid electrical inter dependencies may complicate things...but it's just engineering. I tried to find specs for the electric motor for torque. 100ft lbs? If its a DC motor, it should come on full at 0 rpm. But a Wikipedia entry said AC, which makes no sense. Maybe full specs are on this website somewhere, or someone can provide. Time for some hybrid hot-rodding!