Brake Controller Question

[BradJ]

Hey guys,

All of the sudden on my 1996 F250 PSD I would be going down the road and the transmission will "free spin". Thats the best way I can describe it. It is like it is getting ready to downshift "for no reason" and then slides back into overdrive. Now, you get the exact same response if you just lightly tap the brake..its like a release of some type. Is there a brake switch or something that makes this happen? I can also adjust the gain on my brake box and get the trans to do it at will while drving down the road. Is some connection on the brake box loose or something? I think it is all connected to the problem though.
Thanks for any help or ideas.

Thanks,
Brad

[tractor nut]

youre brake controller should have nothing to do with the tranny unless someone wired it up and hooke the hot wire to a wire running to a sensor in the tranny. but the controller should not affect the tranny

[Dave]

Originally Posted by bobalex

maybe this post from Ford has something to do with it

2005-01 January 4, 2005
Trailer Brake Controller [TBC] 2005 Ford SuperDuty Vehicles
Ford Motor Company asks you to communicate with inspectors and educate them about advances in
technology so inspection practices may be revised accordingly. Customer communications regarding
the integrated Trailer Brake Controller [TBC] installed on the 2005 Ford SuperDuty vehicles indicate that
inspection programs in some states and provinces are incorrectly ticketing vehicles for inoperative trailer
brake systems because they may not fully understand the installed TBC system.
The current inspection entails using a trailer brake controller to manually activate the electric trailer
brake system with the motor vehicle at rest in order to verify the operation of the trailer brakes. Please
note that no regulation requires a manual activator for electric trailer brakes. However, it is common
practice on most existing trailer brake controller designs and hence was available for use in the
aforementioned inspection. After performing the test, it is assumed that the trailer brakes are operating
correctly if the towing vehicle and trailer remains at rest with engine idling, automatic shifter in drive, and
no application of vehicle service brakes.
However, the Ford TBC works differently from all currently available aftermarket trailer brake controllers
because of its integration into the vehicle giving it the knowledge of the vehicle's behavior (speed, brake
pressure, etc). This difference is why some inspection stations have been ticketing Ford vehicles. The
Ford TBC has a manual activation device as do aftermarket controllers; but, it does not function in the
exact same manner. At very low speeds, including at rest, the Ford controller sends a proportionally
smaller amount of output voltage (though not zero) to the trailer brakes to provide smoother stops. This
low-speed adjustment is the reason manual activation of the Ford TBC cannot be used to verify the
operation of the trailer brakes.
1
2005-01 January 4, 2005
Trailer Brake Controller [TBC] 2005 Ford SuperDuty Vehicles
The TBC output voltage also is adjusted according to the gain setting – for lower gain settings (which
are assumed to be the case of a lightly loaded trailer) the output voltage can be very low and, for a
gain setting of zero, the voltage will be zero.
The Ford TBC manual activator is to be used to calibrate the appropriate gain setting of the TBC. This
gain setting determines the maximum available output to the electric brakes. Calibration is performed
by driving at speeds between 15 and 25 mph (24 and 40 km) and manually activating the trailer
brakes. If they lock up, the driver is to tune the gain setting down to the level just below wheel lockup.
For a heavy trailer, the gain setting may be set high; for a lightly loaded trailer the gain setting may be
low, but these also will depend upon road conditions. This is the primary and only suggested use by
Ford for manual operation of the Trailer Brake Controller. In addition, the Ford TBC is capable of
detecting and indicating certain faults in the tow vehicle wiring and the trailer wiring/brake system to
the operator.
At zero speed, the trailer brakes are operable with the Ford TBC by activating the towing vehicle
brakes and therefore satisfy all applicable brake operating regulations. The trailer brakes will be
controlled and operating as designed, but not at the application level that can be expected from
aftermarket TBCs due to the circumstances noted above. Since Ford has evolved the state-of-the-art
in TBC technology, we recommend that inspection criteria evolve to accurately assess correct trailer
brake operation regardless of which TBC is used.
2
2005-01 January 4, 2005
Trailer Brake Controller [TBC] 2005 Ford SuperDuty Vehicles
The first suggestion would be the use of the break-away battery on the trailer to test the trailer brakes
and the emergency brake-away system as required in section 393.43 of the Federal Motor Carrier
Safety Regulation and Standard 11 (b) of the Canadian National Safety Code when the towing vehicle
and trailer are at rest.
The second suggestion would be to drive the towing vehicle and trailer at 15 mph (24 km), at the
maximum gain setting (10.0 for Ford TBC) and manually activate the Ford TBC. If a large
deceleration is felt (a "jerk") the trailer brakes are operating correctly.
If it is absolutely necessary to have a test initiated with the system at rest, a third suggestion would be
to set the controller gain to maximum (10.0 for the Ford TBC) and manually activate the controller with
vehicle in PARK. Have the inspector kneel beside the trailer axles and listen for the "hum" an electric
trailer brake will produce when current is being sent. If the hum is present, the trailer brakes are
operating and the Ford TBC is sending its speed-adjusted output.
Another suggestion for a test with the system at rest would be to disconnect the trailer wiring from
vehicle. Using a wire with clip on one end and a needle on the other (rated for 30A), attach the clip
end of the wire to the battery charge terminal in the vehicle connector attached to the bumper. This
pin corresponds to the black wire, and when looking at the vehicle connector, is in essentially the "1
o'clock" position (or the first pin when traveling clockwise from the 12 o'clock position – refer to figure
below). Then rest the trailer hookup connector so it won't move around easily and insert the needle
end of the wire into the brake output pin on the trailer connector. This pin corresponds to the blue
wire, and when looking at the trailer connector is in essentially the "7 o'clock" position (or, the 4th pin
when traveling clockwise from the 12 o'clock position). This will essentially send 12V to the trailer to
charge the trailer brakes, but will not cause any potential damage to the emergency breakaway
system of the trailer. Take the vehicle out of PARK with engine at idle and make sure the trailer
brakes have engaged by verifying system resistance or trailer wheel lockup after the truck has
traveled a short distance.
3
2005-01 January 4, 2005
Trailer Brake Controller [TBC] 2005 Ford SuperDuty Vehicles
NOTE: When you disconnect the trailer, the Ford system will alert you of trailer disconnection by
blinking the trailer icon (in red) on the TBC face for 30 seconds. This is normal operation of Ford TBC.
The display will then be blank until the trailer is re-connected.
The Ford Integrated Trailer Brake Controller is more advanced and capable than other controllers in
the market as it uses multiple pieces of vehicle information to provide smoother and more balanced
stops proportional to how the vehicle is braking. It adapts to a broad variety of driving scenarios and
provides significantly advanced diagnostic capabilities.
This Inspection Bulletin should be circulated to all inspectors and officers in the field for their
information and guidance. We appreciate your time and assistance in helping resolve safety
inspection issues associated with the release of this more advanced design.
4

That applies to the 2005 and newer trucks with the integrated brake control

[Turbodude]

hey that release is your torque converter clutch unlocking...it will unlock at a ceratin speed as well as when you tap the brakes...i hated it thats why i got a torque converter lock up controller...i was pulling a boat down a pretty steep hill and it was holding, holding, holding, then it unlocked and i went flying down this hill which at the bottom of it had a stop light which conveniently turned red as i was barreling down the hill...i ended up having to smash the throttle to get the converter to lock back up...my advice is to get a lockup controller...everynow and then they have them on ebay for 50 bucks...thats where i got mine from and it works great. and once you get it you can turn your EBPV into an exhaust brake because it will hold as long as you have the torque converter locked.