Your vehicle is not designed to be dinghy towed (with 4 wheels on the ground) behind a motor home.
Notice
To avoid serious damage to your vehicle
Do not tow your vehicle with 4 wheels on
the ground. 
To prevent causing serious damage to the transmission and dynamic torque control awd system (awd models)
2Wd models: never tow this vehicle from
the rear with the front wheels on the
ground. This may cause serious damage
to the transmission. 
Awd models: never tow this vehicle with
any of the wheels on the ground. This
may cause serious damage to the transmission
and dynamic torque control
awd system. 
Trailer towing tipsSteering angle sensor
Components
Removal
Precaution
Caution:
Be sure to read the "precaution" thoroughly
before servicing (see page rs-1).
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery termin ...
If a warning light turns on or
a warning buzzer sounds
Calmly perform the following actions if any of the warning
lights comes on or flashes. If a light comes on or flashes, but
then goes off, this does not necessarily indicate a malfunction
in the system. However, if this continues to occur, have
the vehicle inspected by your Toyota dealer.
Actions to ...
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "suspected area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Re ...