Subaru Forester 2.5X 2003 Technicians Reference Booklet page 28

2003 New Model Update
The OnStar system is equipped with on board
diagnosis. The system can perform a DTC check
that will evaluate the condition of inputs and
outputs as well as perform a compulsory check
mode.
Entering the DTC check mode is accomplished
using the "Dot" button and the ignition key.
Follow the chart below to enter the DTC check
mode.
1. Push and hold the "Dot" button
2. With the ignition key off cycle the ignition key
to on 4 times within 6 seconds.
3. Release the "Dot" button.
Results
Normal condition-The green LED will turn off and
back on steady.
Red LED will flash to indicate a current problem.
Green LED will flash to indicate a code has
occurred in the past but does not
exist.
Number
of
Flashes DTC
1 GPS signal error
2 Loss of VCU to VIU
communications
3 SRS signal fault
(Only flashes green Only flashes green) Only flashes green Only flashes green Only flashes green
4 GPS and Mircroprocessor
communication fault
5 Button assembly malfunction
Exceptions
During
communication fault, DTC occurs that disables
the button module the VIU will not enter the DTC
display mode.
The EEPROM checksum error, DTC shows a
transition in the memory but does not mean there
is a fault. Therefore no DTCs are displayed.
The SRS signal fault DTC will only show as
history in the DTC display mode. (Requires
ignition to enable algorithm and the ignition is
96
the only reference for entering the DTC display
mode.
The DTC codes will be displayed in two cycles.
Current codes are always displayed first,
followed the DTCs in memory.
The codes with the least number of flashes are
displayed first.
Five codes or less shall be displayed in the same
cycle.
The same code shall not be displayed more than
once.
Deleting DTC codes
DTC history status can be cleared at the end of
the Display mode by pressing and releasing the
OnStar button within 3 seconds at the end of the
DTC display mode.
Output mode
Output mode can be used to enter a compulsory
check of the lock, unlock, security system, horn,
and light outputs.
currently
The output mode can be entered at the end of
the DTC display mode by switching the ignition
to off within 3 seconds at the end of the DTC
display mode. (LED returning to normal
condition).
Order of occurrence
1. Security arm signal
2. Door lock
3. Security indicator
4. Security disarm
5. Door unlock
6. Horn and lights
28
(912) Legacy
a GPS and microprocessor
Length of signal
20 milli seconds
300 milli seconds
1.125 seconds
80 milli seconds
300 milli seconds
750 milli seconds
June 2002