MITSUBISHI ELECTRONICS AMERICA, INC.
ST200 Series Technical Support Manual
82
January 2000
complete calls. The signal strength may be too low because of signal blockage, improper
installation of the antenna or beam steering unit (BSU) or corroded connections. Defective
antenna units can also result in low signal strength.
For the ST211, when the Auto-On feature is selected, the vehicle must be at a stand still or
driven in a straight line for the first 10 seconds after start up. This procedure will allow the BSU
time to calibrate.
What to Check
What to do
1. Did the signal strength gradually decline
over several days?
This symptom is usually related to an antenna
failure. Replace the antenna to see if that
resolves the problem.
2. Are the connections between the AU and
TU secure and corrosion-free?
Look at the connections and make sure the
pins are straight and rust-free. Keep
insulating or water sealing materials outside
of the connection.
3. Are the right cables being used?
Follow the installation instructions, since
excess cable length or incorrect type can
reduce signal strength.
4. Is the BSU installed correctly?
Review installation instructions and make
sure the BSU is mounted upright, in the
direction of the arrow.
5. For the ST251 only-Is the transceiver fully
inserted and seated properly inside the base
unit?
Improper installation of the TU can cause
degradation in signal strength.
