C0040 brake problems

Reply Subscribe

Thread Tools

Search this Thread

Aug 4, 2024 | 04:31 PM

Tideman

Thread Starter

Fleet Mechanic

Joined: Nov 2008

Posts: 1,443

Likes: 9

From: South Alabama

C0040 brake problems

2015 f350 6.7. 133,400 miles Driving home yesterday and cruse would not engage. Few miles down the road several things flashed on the dash including traction control, ABS and check brakes. Turn signals blinked rapid. Drove 40 miles to the house without a problem except cruse would still not work. It would turn on but not set. Got home and brake lights will not turn off. After an hour I pulled the fuses. Only code other than C0040:73-48 is a DEF code that has been on for a year. Can’t figure it out. Help

Aug 4, 2024 | 05:18 PM

senix

Super Moderator

Joined: Aug 2008

Posts: 37,377

Likes: 1,861

From: Frederick, MD

when it the last time you put in new batteries?

Did you drive in the rain?

Aug 4, 2024 | 05:24 PM

Tideman

Thread Starter

Fleet Mechanic

Joined: Nov 2008

Posts: 1,443

Likes: 9

From: South Alabama

Batteries are 2 years old and strong. Yes I do drive in the rain. Was not raining yesterday when this went haywire

Aug 4, 2024 | 06:31 PM

djousma

Logistics Pro

Joined: Mar 2005

Posts: 3,530

Likes: 2,494

From: West Michigan

Check/unplug/plug the large connector by the e-brake. It has been known to work loose causing these kinds of problems

Aug 4, 2024 | 08:03 PM

Tideman

Thread Starter

Fleet Mechanic

Joined: Nov 2008

Posts: 1,443

Likes: 9

From: South Alabama

Going to try that tomorrow. Can’t get my old hands up in there. Will get neighbor to do it. Thanks for the reply

Aug 5, 2024 | 05:09 PM

Tideman

Thread Starter

Fleet Mechanic

Joined: Nov 2008

Posts: 1,443

Likes: 9

From: South Alabama

The final on this is it was the brake petal switch. I called myself checking that but evidently I didn’t. Thanks to you guys who replied.

Remember C0040:73-48 was the DTC an odd one