GMC Express 2011 Owner's Manual page 269

The seven-wire harness connector
contains the following trailer circuits:
Light Green: Back-up Lamps
(10A fuse)**
White: Ground
Dark Blue: Trailer Brake Signal
Dark Green: Right Rear Stop
and Turn Signal*
Red/Black Stripe: Battery Feed
(30A Fuse)
Brown: Trailer Park Lamp
Supply Voltage (15A fuse)**
Yellow: Left Rear Stop and
Turn Signal *
The four-wire harness (without
connector) contains the following
circuits:
Black: Ground
Red/White: Battery Feed
Dark Blue: Trailer Brake Signal
Light Blue: CHMSL/Stoplamp
Supply Voltage
* If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for both left/stop trailer
turn and right/stop trailer turn
signals. However, the cutaway
lighting connector will have a
10 amp fuse for each signal.
** If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for trailer park lamps and
cutaway rear lighting connector park
lamps. Also, a 10 amp fuse will be
shared for trailer back-up lamps and
cutaway rear lighting connector
back-up lamps.
Driving and Operating
Tow/Haul Mode
This button is on the instrument
panel, to the right of the steering
wheel.
Pressing this button turns on and off
the tow/haul mode.
This indicator light on the instrument
panel cluster comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See Tow/Haul
Mode on page 9 31 for more
information.
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