Troubleshooting Factory Integrated Electric Brake Controller on 2008 F-350

Published 12/13/2019

Question:

Checking the factory-installed integrated brake controller in my 2008 F350 diesel, we noted the controller lit up with tester attached, the bars of electricity going to the tester hooked to the rear plug went up and down with either the brake pedal or manual slide applied. But the voltage was high 12 V when set at maximum with the engine running, truck at a stand still, pointed slight uphill. Voltage with the brake pedal was present but minimal under these conditions. I assume because the truck wasnt moving and, in fact, slightly uphill that the circuitry that integrates the brake pedal and controller simply wasnt putting out much voltage and this is normal. Am I correct and the controller appears to be operating properly?

asked by: Thomas R

Helpful Expert Reply:

It sounds like the brake controller is working properly and is acting normal. The factory integrated brake controller on your 2008 Ford F-350 Diesel is a proportional brake controller. It applies the brakes to the trailer in the same intensity and time as your truck, however there's a small amount of voltage constantly running through the circuit so your F-350 can detect if the trailer is hooked up or not.

So with truck was sitting still and the engine running, you should not have any voltage rise when the pedal is pressed, if you do it will be very minimal because the brake controller realizes you are sitting still and doesn't see any deceleration.
However if you slide the manual override you should have a rise in voltage. The manual slide will apply the brakes whether you are moving or not, but only when the trailer is hooked up.

You can check out the article I linked for more information on the different kinds of brake controllers and how to test and adjust them.

expert reply by: Robert C