Car bucks when slowing down to a stop

[ewdixon99]

I have a 2013 ford fusion energi (hybrid plug-in) and the car is bucking when slowing down to a stop. Not all the time but I notice it's doing it when the engine is running to charge hybrid battery. I'm thinking it's the transmission. The car is no longer under warranty (130,000 miles). Can I take it to any transmission repair shop or should I take it to the Ford Dealer?

[eisbaer]

Ford dealer $$$$$

other shop $$ (depending)

do you have any experience or do you need to have someone else look at it?

[ewdixon99]

I don't have any experience with this type of transmission. I'm a take to the shop and get raked over the coals kind of guy. Trying not to do that anymore. 

[2014FordFusionSE]

8 hours ago, ewdixon99 said:

I have a 2013 ford fusion energi (hybrid plug-in) and the car is bucking when slowing down to a stop. Not all the time but I notice it's doing it when the engine is running to charge hybrid battery. I'm thinking it's the transmission. The car is no longer under warranty (130,000 miles). Can I take it to any transmission repair shop or should I take it to the Ford Dealer?

 

Get a few opinions for sure.

You'll probably hear different things so be prepared for that.

[eisbaer]

11 hours ago, ewdixon99 said:

I don't have any experience with this type of transmission. I'm a take to the shop and get raked over the coals kind of guy. Trying not to do that anymore. 

ok, just checking. It may have nothing to do with the transmission is why i ask. But best to get it looked at. Either the dealer or a third party diagnosis but get a few different opinions. They may charge a fee but dont tell them you have had others look at it and their personal UN-purswayded diagnosis.

Let us know, goodluck!

[murphy]

This is an eCVT transmission (electric constant velocity transmission).  There are no gears to shift.  Reverse is achieved by reversing the rotation of the electric field in an electric motor.  It is impossible for the engine to move the car in reverse directly.  You need someone that has worked on a Ford hybrid or a Toyota hybrid.

 

[lolder]

It's unlikely that it's the transmission unless it has been making a grinding noise for a long time. common to early 2013+ FFHs.  There's nothing to cause "bucking" in it, no clutches, bands, torque converters, valves, actuators, etc. It's only gears rolling on gears. Check brakes and other components. 

[ewdixon99]

Thanks I will get a few diagnostic test done and see what they say! 

[aschulz261]

I have noticed that mine does it, but ONLY when in hill descent mode, the battery is full and the ICE is running to help maintain speed.  It is not smooth at all when coming to a stop.  It seems to be a rare set of circumstances that I don't think the programming is especially good at.

[ewdixon99]

Had a diagnostic test done and it cost 130 bucks. Then I get a code scanner in the mail today. I run the scan and I get the same code plus one more!

Basically, it seems to be an issue with the ECM/PCM and the BEC. It's an computer issue. My mechanic says I should take it to the dealer to fix. He can't do it.

?

[2014FordFusionSE]

You've probably googled it and found this:

https://repairpal.com/obd-ii-code-u0100-lost-communication-with-ecm-pcm-a

 

How old is your 12v battery?

 

From the link above, one of the items is:

Check the battery

Before proceeding, a technician will make sure the battery is fully charged. The PCM needs a proper power supply to function. Charge or replace the battery as needed.

[Vlad Soare]

Did you by any chance find out what the problem was? Mine (2017, 20K miles) behaves the same. There's a sudden jolt when I brake hard. I suspect something in the transmission, but I don't know what it could be. Theoretically there's nothing in the transmission that could explain it.

Edited August 30, 2020 by Vlad Soare

[ewdixon99]

Yes the issue was the speed sensors on both front wheels were the problem. It was a $500 fix but car is so much better now. My first dealer experience wasn't a nightmare.    

[Vlad Soare]

Thank you. That's reassuring. I was afraid that the transmission might be failing.