Throttle body / limp mode / ECU issue?

[kmarnes]

I don't really know what's wrong with my car, but it's happened since I bought it new -- but it was super rare like maybe once or twice per year. Always when going up hills when accelerating from a stop or from a slow speed. The steeper the hill, the easier it is to repro.

Last couple weeks, it's happened 5 or 6 times, so it's time to get it looked at. I made a video, so hoping someone can confirm the issue. I think the car is going into limp mode where I get minimal power. When I floor it, it just goes super slow but it pulsates brief accelerations.

A couple years ago I asked the service people about it and they couldn't repro the issue. And it didn't happen often enough to be super concerned. This has never happened in highway conditions. Just milling around town.

It's super unsafe because I was turning left at an intersection and lost power halfway through the turn.

I only have 37,000kms on the car -- it's almost 5 years old now.

 

[Odrapnew]

Seems like it could be the throttle body not opening or 'flapping.'

Didn't some of these have an issue with the throttle body not responding to pedal inputs?

 

[peterk9]

The 2016 was known for throttle body issues.

Peter

 

[peterk9]

I don't really know what's wrong with my car, but it's happened since I bought it new -- but it was super rare like maybe once or twice per year. Always when going up hills when accelerating from a stop or from a slow speed. The steeper the hill, the easier it is to repro.

Last couple weeks, it's happened 5 or 6 times, so it's time to get it looked at. I made a video, so hoping someone can confirm the issue. I think the car is going into limp mode where I get minimal power. When I floor it, it just goes super slow but it pulsates brief accelerations.

A couple years ago I asked the service people about it and they couldn't repro the issue. And it didn't happen often enough to be super concerned. This has never happened in highway conditions. Just milling around town.

It's super unsafe because I was turning left at an intersection and lost power halfway through the turn.

I only have 37,000kms on the car -- it's almost 5 years old now.

It usually only goes into 'Fail-Safe Cooling' (limp mode) when the engine overheats. Sounds like a trip to the dealer may be in order. If you are a DIY person, you could try cleaning the throttle body first. Powertrain warranty runs out at 5 years or 100k kms.

Peter

 

[kmarnes]

It's a 2017 Sport. It's definitely not an overheating issue as another frequent location for me is a popular crosswalk near my home on the way to drop my kid off at school. When I stop, I have a chance of limping. It's on a hill as well. I also have an extended warranty, so not concerned about that.

Also it seems to only happen going up hill. Once things "reset" by mucking with gears, manual shifting etc and I'm on level terrain again, everything goes back to normal, and I've never experienced issues on long road trips.

 

[kmarnes]

Update: Ford diagnosed it today -- was able to repro the issue. Looks like my transmission fluid was short 4L... which seems like a lot! May be covered under warranty, but they topped it up and added some tracer material to it and want me to come back in a week. Doesn't seem like it's leaking, so it's a mystery where it's going. Stay tuned.

In any case, didn't encounter any issues going up hill after picking it up!

 

[peterk9]

Thank you for the update, That 4L, or just over 4 quarts U.S., is about half of the transmission's capacity (8.5L).

Peter

 

[kmarnes]

Driving the car around since the top-up, it feels like a new car. Loss of power was an extreme example, but another problem I struggled with since day one is clunky confused shifting. Like say I was going 50km/h and hit the gas... the car would often take a couple seconds to think about it -- while stalling slightly before suddenly surging. I adapted my driving style by going more soft-touch on the throttle. I always attributed that to a 6 speed clunky transmission, but seems I may have been wrong.

I'm starting to suspect that I've been driving the car short on transmission fluid since the day I bought it. No indication of leak. But only 37,000 km in 5 years. Car feels new now and acting the way I expected it should be.

I'll find out more later this week after they take a second look at it. But I'm pretty happy!

I don't have any of those issues anymore. No hesitation, smooth shifting, no loss of power in any scenario.

 

[kmarnes]

Okay it's officially fixed. My factory warranty expired one day after I dropped it off, though because it was diagnosed before that, I would have been fine anyway. They pulled the transmission and redid the seal. So if anyone wants the technical details, here's my service documentation. If anyone else encounters sudden loss of power when going uphill, get the dealer to check transmission fluid level. If it's really low (4L-6L out of 8L) then this is likely your fix. Mine got worse gradually over time. Initially it was super rare, but then became very common once it got down to 4L.

About 20 hours of tech work. Right now with Covid and part shortages, my car was unnecessarily in the shop for a full week waiting for parts despite everything being setup in advance. At least I had a loaner.

diag for loss of power going up hills. diag found the transmission
is down 4L of fluid. will need an inspection for the transmission leak.
possible leak from a drain plug. CLEANED AND RE-SEALED
TECH 8223. REMOVED INTAKE. REMOVED BATTERY TRAY, REMOVED UPPED BELL
HOUSING BOLTS REMOVED SUB FRAME. REMOVED RIGHT SIDE TURBO, REMOVED PTU,
REMOVED TRANSMISSION. BENCH MOUNTED TRANSMISSION. RESEALED CASE HALF AS
PER TECH 9792 DIAG. REASSEMBLED. PERFORMED ALIGNMENT CHECK AND ADJUSTED
FRONT TOE, PRINT OUT WITH PAPER WORK ROAD TESTED OK.

Automatic Transmission Assembly (7000) - Remove and Install or
Replace 6F50/55,3.5L GTDI 7000A<8.2 Refer=t Operation: 30010"
check and adjustmentwhen=requiredby..the Workshop Manu

Extra time if equipped

Extra Time For A Post-Rep
Extra time to mount transn
Automatic Transmission §
7F401)- Replace 635 700
Transmission Case Haly
Caster, Camber, Toe-In= c
Caster, Camber and Toe-in (3B

Turbocharger Assembly (6K682/ 9G438/ 91T514)- Remove and Install or Replace