Battery removal

[Sinovac]

There were a string of cars that had some ignition board fault and wouldn't let the car start. Seems like they were K models. Simply replace the board and problem solved.

Once again a good question for Italian Joe.

My car is K104. Thank you. I will put this on my list to check.

 

[Sinovac]

Clint and David, I’ll recheck the ground and relay.

 

[italianjoe]

My initial thought was my battery was weak because the electronics would boot up, but when I applied the brake and pushed the start button, all I got was a short hum and a thunk. I load tested the battery and it tested good. I then tried to jump the car. Still not starting, so I’m thinking it’s something else. The battery in the key fob is new. I tried both procedures in the owners manual (placing the key fob under the rubber console mat and also depressing both the brake and accelerator pedals while attempting to start). The warning in the picture below flashes intermittently for a split second and disappears. It happened so quick that I had to take a video and grab a screenshot. It doesn’t flash the warning all the time. Due to the cost of the battery, new tray, etc., I don’t want to replace the parts unnecessarily. If the battery was bad, it should have started while being jumped. Any ideas?
View attachment 70070

Hello sinovac, I have seen this issuse before and the hum noise gives it away. It sounds like the soft start module has failed and is easy to check. Just below the coolant bottle in the rear you will find a rectangular box with two large electrical cables mounted to it. Disconnect the negative battery cable then go to the soft start module and have both the battery cables bolted to one of the lugs reconnect the battery and try to start your car. If it works you need to replace the soft start module.

Hope this helps

Joe

 

[Specracer]

Curious, what does a "soft start module" do if the car will start with this module bypassed?

 

[italianjoe]

Curious, what does a "soft start module" do if the car will start with this module bypassed?

The soft start module allows only the necessary amount of amperage to the starter. If it had full battery amperage all the time to the starter it may cause starter to overheat and/or damage to the starter. The lithium ion battery stores a lot of energy.

Joe

 

[68Rcodeman]

Hill assist in Florida huh? Sounds like it's a GPS problem

No it was a communication fault. No odometer reading and PCM didn't recognize the key was on or button was pushed to start. Hill assist is part of traction control ABS.

 

[Specracer]

The soft start module allows only the necessary amount of amperage to the starter. If it had full battery amperage all the time to the starter it may cause starter to overheat and/or damage to the starter. The lithium ion battery stores a lot of energy.

Joe

Makes perfect sense, learn something new every day (especially with this complicated car), thank you Joe!

 

[fjpikul]

Codeman I am teasing. How many hills are there in Florida?

 

[Sinovac]

Thank you very much Joe. I will check that.

 

[Indy GT]

ItalianJoe is certainly a technical asset to this Forum!!!
Thanks Joe.....

 

[Sinovac]

Joe, you THE MAN. You accurately diagnosed the problem. Please send me a PM with your address. I want to send you something to show my appreciation. I insist.

I will post additional information and photographs for future reference.

 

[Sinovac]

For future reference, the failure of the soft start module in my case started with an intermittent no crank situation, then progressed to a complete failure to crank, similar to what you might experience if the battery was failing. The complete failure causes a short hum and thunk, with no cranking, when attempting to start the car.

As Joe stated, the soft start module can be bypassed to test it. The module is just behind the coolant bottle shown on the left side of the engine in the picture below. This picture shows the coolant access panel on the main carbon panel removed.

 

[Sinovac]

Remove the 3 screws shown here on the carbon fiber panel, and 1 more towards the front, and move the panel aside.



This is the soft start module with the cables in their normal position.



Remove the right front wheel and the inner splash shield, which is attached with pushpins, and disconnect the negative battery cable, which is easily accessible.

Bypass the soft start module by attaching the cables to the same lug as shown below.



Reattach the negative battery cable and start the car. In my case, the car immediately started, indicating a failed soft start module.

Dave, please change the title to this thread to No cranking/soft start module failure or something along those lines for future reference.

Another big thanks to Joe for taking the time to diagnose this.

 

[Sinovac]

Service manual description of the soft start module…

 

[Nafod]

Remove the 3 screws shown here on the carbon fiber panel, and 1 more towards the front, and move the panel aside.

View attachment 70104

This is the soft start module with the cables in their normal position.

View attachment 70105

Remove the right front wheel and the inner splash shield, which is attached with pushpins, and disconnect the negative battery cable, which is easily accessible.

Bypass the soft start module by attaching the cables to the same lug as shown below.

View attachment 70106

Reattach the negative battery cable and start the car. In my case, the car immediately started, indicating a failed soft start module.

Dave, please change the title to this thread to No cranking/soft start module failure or something along those lines for future reference.

Another big thanks to Joe for taking the time to diagnose this.

Nice write up. Thank you Sinovac.

 

[fjpikul]

Seems like the Ford tech writers need some English lessons on use of the word "lessens."

 

[Sinovac]

There is a black cover over the module. Unclip it from the top, then push down to remove.

 

[NSXER]

Is the new "smaller" battery easier to change out at a later date? Is the removal process the same as the older large battery?
Thanks
Brian

 

[italianjoe]

Is the new "smaller" battery easier to change out at a later date? Is the removal process the same as the older large battery?
Thanks
Brian

Hello Brian, my parts manager told me you had called. As for the removal and install......its about the same. The lithium ion batteries are light and not as heavy as a lead acid battery.

Joe

 

[NSXER]

Hello Brian, my parts manager told me you had called. As for the removal and install......its about the same. The lithium ion batteries are light and not as heavy as a lead acid battery.

Joe

Joe,
Thanks for the reply and I received your message. Just trying to decide to put in the smaller battery with the new mount or go with another the same size (lithium of course) and use the "old" mount.