FORD 2008 F-550 v.4 - Manual (Page 249)

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 messages:
The TBC interacts with the instrument cluster message center. These
messages, accompanied by a single chime, will be displayed when the
TBC determines a malfunction in the trailer connection, TBC system, or
in the trailer. These messages are listed below:
TRAILER DISCONNECTED (if equipped with message center) or
CHECK TRAILER (if equipped with mini message center): This
message is displayed when a trailer connection was determined and then
a disconnection, either intentionally or unintentionally, has been sensed
during a given ignition cycle. It is also displayed if a trailer fault occurs
causing the trailer to appear disconnected. This message is also
displayed during manual activation without a trailer connected.
TBC FAULT: This message is displayed in response to faults sensed by
the TBC. In the event this message is seen, please take your vehicle to
an authorized dealer for diagnosis and repair. The TBC may still function,
but performance may be degraded.
WIRING FAULT ON TRAILER: The TBC is capable of determining
certain faults in the vehicle wiring and trailer wiring/brake system. These
faults do not mean there is anything wrong with the TBC. This message
is displayed when one of the following faults has occurred:
• Short circuit on the electric brake output wire: If the TRAILER
FAULT message is displayed with no trailer connected, the problem is
with the vehicle wiring from the TBC to the 7–pin connector in 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.
Points to Remember:
• Remember to adjust gain setting before using the TBC for the first
time.
2008 F-250/350/450/550 (f23)
Owners Guide (post-2002-fmt)
USA (fus)
Tires, Wheels and Loading
249