
READ GPS DATA
The common misconception made by service personnel when diagnosing navigation system performance is to
suspect satellite reception as the cause of the fault. In reality, the GPS data sensed by the computer is only
processed every few seconds to confirm that the position calculated by the map matching software process is
correct. Good GPS data is essential to the system when it is first installed in the vehicle, or when the vehicle is
moved from one location to another without the navigation system being active.
Within the SATNAV computer unit, there is a separate GPS receiver, which receives the GPS signal from the
antenna and passes calculated information to the SATNAV computer’s processor. If it is concluded that the GPS
receiver is faulty, the SATNAV computer must be replaced.
RECEI V ER STATE DESCRI P TI O N COMMENT
3D POSITION 3D data on the loc ation of
the vehicl e i s available when
four or more satellites are
received by the s ystem .
In this c ondit i on, the satellite ic on on the guidance screen is GREEN.
This is t he normal condi tion.
2D POSITION 2D data on the loc ation of
the vehicl e i s available when
three or more satellites are
received by the s ystem .
No geographic height can be determ i ned i n t h i s mode. Positi onal
accurac y i s reduced.
The satellite ic on on t he guidance screen is RED. This is not the normal
conditi on, but indicat es poor or reduced reception.
TRACKING The data from one satellite
has been received by t he
system.
This condi tion is normally encount ered when the s ystem i s firs t powered
up. The GPS rec eiver will be in this mode for up to 10 minutes
depending upon recepti on conditions .
The satellite ic on on the guidance screen is RED.
SEARCH S A T The syst em has a vali d
almanac and is searching
for satellites.
This condi tion is normally encount ered when the s ystem i s firs t powered
up. The GPS rec eiver will be in this mode for up to 10 minutes
depending upon recepti on conditions .
The satellite ic on on the guidance screen is RED.
REC ERROR The system does not
receive the s i gnal s. This condition usually occurs if the GPS ant enna i s not connec ted or the
cable is damaged. A failed GPS receiver could be t he condition.
The satellite ic on on the guidance screen is RED.
COM ERROR The GPS recei ver is not
providing any data t o the
SATNAV comput er’s
processor.
Internal c omm uni cation between the GPS receiver and the SA TNA V
com puter is not possible.
READ ERROR MEMORY
The self-diagnosis function of the computer stores
error events to its internal memory. The errors
detected may be due to internal (computer) or
external (environmental or vehicle) conditions. You
may need to view this screen when asked by a
VDO tec hnical consultant during the cour se of fault
diagnosis.
Figure 8B-40
ME NU ITEM DESCRIPTION COMMENT
ERROR CODE Lists the errors t hat have
occurred. Scroll through the errors us i ng the < and > buttons. Press OK when
each error is hi ghl i ghted to see a des cription of the error.
ERROR FREQUENCY The number of t i mes t he
error has occ urred.
SW Software error.
HW Hardware error.
SENSOR No VSS signal.
TEMP Temperature extreme has caus ed system
error.
GPS Lack of s at ellit e signal.
ERROR TYPE Shows the error type.
NO FAILURE No errors have occ urred.