RESTRAINT CONTROL SYSTEM
9J1–4
System Schematic
D09RW014
SRS Diagnostic System Check
The diagnostic procedures used in this section are
designed to find and repair SRS malfunctions. To get the
best results, it is important to use the diagnostic charts
and follow the sequence listed below:
A. Perform the “SRS Diagnostic System Check.”
The “SRS Diagnostic System Check” must be the
starting point of any SRS diagnostics. The “SRS
Diagnostic System Check” checks for proper “AIR
BAG” warning lamp operation, the ability of the SDM
to communicate through the “Serial Data” line and
whether SRS diagnostic trouble codes exist.
B. Refer to the proper diagnostic chart as directed by the
“SRS Diagnostic System Check.”
The “SRS Diagnostic System Check” will lead you to
the correct chart to diagnose any SRS malfunctions.
Bypassing these procedures may result in extended
diagnostic time, incorrect diagnosis and incorrect
parts replacement.
C. Repeat the “SRS Diagnostic System Check” after any
repair or diagnostic procedures have been
preformed.
Performing the “SRS Diagnostic System Check” after
all repair or diagnostic procedures will ensure that the
repair has been made correctly and that no other
malfunctions exist
Circuit Description
When the ignition switch is first turned “ON”, “Ignition 1”
voltage is applied from the “C–21” fuse to the SDM at the
“Ignition 1” input terminals “12”. The SDM responds by
flashing the “AIR BAG” warning lamp turn on 3.5 seconds,
while performing tests on the SRS.
Notes On System Check Chart:
1. The “AIR BAG” warning lamp should turn on 3.5
seconds after ignition is first turned “ON”.
2. After the “AIR BAG” warning lamp turn on 3.5
seconds, it should turn “OFF”
3. This test checks for the proper operation of the
“Serial Data” line. This test will also determine
whether history diagnostic trouble codes are stored
and, if so, identify them.
4. Improper operation of the “AIR BAG” warning lamp
is indicated. This test differentiates a warning lamp
stays “ON” condition from a warning lamp does not
come “ON” condition.
5. This test checks for proper operation of the “Serial
Data” line. This test will also identify the stored
diagnostic trouble codes and whether they are
current or history.
Diagnostic Aids:
The order in which diagnostic trouble codes are
diagnosed is very important. Failure to diagnose the