FORD 2011 F-550 v.2 - Manual (Page 254)

2. Hook up the trailer and make the electrical connections according to
the trailer manufacturer’s instructions.
3. When a trailer with electric brakes is plugged in, the TRAILER
CONNECTED message will display in the instrument cluster message
center.
4. Use the GAIN adjustment (+/-) buttons to increase or decrease the
GAIN setting to the desired starting point. A GAIN setting of 6.0 is a
good starting point for heavier loads.
5. In a traffic-free environment, tow the trailer on a dry, level surface at
a speed of 20–25 mph (30–40 km/h) and squeeze the manual control
lever completely.
6. If the trailer wheels lock-up (indicated by squealing tires), reduce the
GAIN setting; if the trailer wheels turn freely, increase the GAIN setting.
Repeat Steps 5 and 6 until the GAIN setting is at a point just below
trailer wheel lock-up. If towing a heavier trailer, trailer wheel lockup may
not be attainable even with the maximum GAIN setting of 10.
Explanation of instrument cluster warning messages:
The TBC interacts with the instrument cluster message center to display
the following messages:
TRAILER BRAKE MODULE FAULT: This message is displayed and
accompanied by a single chime, in response to faults sensed by the TBC.
In the event this message is seen, please contact your authorized dealer
as soon as possible for diagnosis and repair. The TBC may still function,
but performance may be degraded.
WIRING FAULT ON TRAILER: This message is displayed when a
Short circuit on the electric brake output wire has occurred. If the
WIRING FAULT ON TRAILER message is displayed and accompanied
by a single chime, with no trailer connected, the problem is with the
vehicle wiring from the TBC to the 7–pin connector under the bumper. If
the message is only displayed with a trailer connected, the problem is
related to the trailer wiring; consult your trailer dealer for assistance.
This can be a short to ground (i.e., chaffed wire) or a short to voltage
(i.e., pulled pin on trailer emergency break-away battery) or trailer
brakes drawing too much current.
Note: Your TBC can be diagnosed by your authorized dealer to
determine exactly which trailer fault has occurred; however, if the fault
is with the trailer this diagnosis is not covered under your Ford
warranty.
Tires, Wheels and Loading
254
2011 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)