Electric trailer brakes are kicking out due to anti-lock brakes

Check for the trailers brakes dragging.

I would think the anti-lock brake system would prevent you from being able to lock up the brakes.
If the truck is hard to stop, there could be a glazing on the pads and rotors.

TBC means Trailer Brake Controller fault.Check for moisture/water in the trailer plug connector at the back of your truck. Water/moisture will cause TBC error codes. Look for moisture at all connections to the plug and inside the plug.Trailer brake controller that is built into your dash. If you are hooked up to a trailer it could mean you are losing your connection or ground to the trailer. If you are not connected to a trailer it means there is a problem with your brake controller possibly a short in the wiring caising the fault code. ----- It means either A) you have a bad ground on your trailer. Or B) your cable on your trailer is too short and causing it to pull out of the plug or C) you have a short in the factory trailer harness wiring or the plug is gunked up. --------- get this possibilities checked.It will help.Thanks.Helpmech.

2006 Sienna Standard towing specs:

2WD or 4WD: Max Tongue Weight: 200 lbs
Max trailer and cargo weight: 2,000 lbs;
(over 1,000 lbs requires trailer brakes)

Max trailer and cargo weight: 3,500 lbs WITH the factory tow package

Thanks for using FixYa!

look in the driver door it will tell you i pull a gooseneck with 30000 on it all the time with no prolbem my wieght is 30000

That is your trailer brake controller that is built into your dash. If you are hooked up to a trailer it could mean you are losing your connection or ground to the trailer. If you are not connected to a trailer it means there is a problem with your brake controller possibly a short in the wiring caising the fault code.

Check your electric brake setting, you need to adjust down the sensitivity setting, check the voltage at the lead where you connect the trailer plug with brakes applied then check the same plug on your RV and compare the two... Check grounds in the circuit...

In the fuse box under the hood, fuse in position 20 is a 7.5amp fuse for the trailer left turn circuit, fuse in position 22 is a 7.5 amp fuse for the right turn circuit, if the fuses are good and you have power at them it is going to be wiring, at the back of the truck close to the driver side at the bumper is a gray connector that will take factory wiring to you trailer wiring the yellow wire is left turn/brake light, the green wire is right turn/brake light, and the brown is tail lights, and the orange wire is 12volt feed for if there is a battery on the trailer that needs to be kept charged for break away safty brakes.

As listed in the owners manual.

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to
pull a trailer are all important. It can also depend
on any special equipment that you have on
your vehicle, and the amount of tongue weight the
vehicle can carry. See “Weight of the Trailer
Tongue” later in this section for more information.
Maximum trailer weight is calculated assuming
only the driver is in the tow vehicle and it has all
the required trailering equipment. The weight
of additional optional equipment, passengers and
cargo in the tow vehicle must be subtracted
from the maximum trailer weight.
The following charts show how much your trailer
can weigh, based upon your vehicle model
and options.
2WD Extended Cab Axle Ratio Maximum Trailer Weight GCWR*
Automatic Transmission,
2.9 L Engine 3.73 3,100 lbs (1 406 kg) 7,000 lbs (3 175 kg)
Manual Transmission,
2.9L Engine 3.73 2,100 lbs (952 kg) 6,000 lbs (2 721 kg)
4WD Crew Cab Axle Ratio Maximum Trailer Weight GCWR*
Automatic Transmission,
3.7L Engine 3.73 4,000 lbs (1 814 kg) 9,000 lbs (4 082 kg)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded
vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your
vehicle should not be exceeded.