warning ISUZU TROOPER 1995 Workshop Manual

9J-22 Supplemental Restraint System
AIR BAG TO EXPAND IN THE UNLIKELY EVENT OF
ACCEIDENTAL DEPLOYMENT. FAILURE TO
FOLLOW PROCEDURES MAY RESULT IN
PERSONAL INJURY.
26. Temporarily store the inflator module with the bag
facing up, away from the surface upon which it rests.
27.
Call the Technical Assistance group for further
assistance.
DEPLOYMENT INSIDE VEHICLE(VEHICLE
SCRAPPING PROCEDURE)
Deployment inside vehicle is proper when the vehicle is
to be destroyed or
salvaged for component parts. This
includes, but is not limited to, the following situations.
1. The vehicle has completed its useful life.
2. The vehicle has been damaged beyond repair in a
non-deployment type accident.
3. The vehicle has been stripped or damaged beyond
repair
in a theft.
4. The vehicle will be salvaged for component parts to
be
used on a vehicle with a different Vehicle
Identification Number (VIN) as opposed to being
rebuilt as same VIN. Never use SRS components
from another
vehicle. This is done to ensure SRS
system integrity since only new SRS system
components.
WARNING: FAILURE TO FOLLOW PROPER SRS
INFLATOR MODULE DISPOSAL PROCEDURES
CAN RESULT IN AIR BAG DEPLOYMENT WHICH
MAY CAUSE PERSONAL INJURY. UNDEPLOYED
INFLATOR MODULES MUST NOT BE DISPOSED OF
THROUGH NORMAL REFUSE CHANNELS. THE
UNDEPLOYED INFLATOR MODULE CONTAINS
SUBSTANCES THAT CAL CAUSE SEVERE ILLNESS
OR
PERSONAL INJURY IF THE SEALED
CONTAINER IS DAMAGED DURING DISPOSAL.
DISPOSAL IN ANY MANNER INCONSISTENT WITH
PROPER PROCEDURES MAY BE A VIOLATION OF
FEDERAL, STATE AND/OR LOCAL LAWS.
1. Turn ignition switch to "LOCK," remove key and put
on safety glasses.
2. Remove all loose objects from front seats.
3. Disconnect driver inflator module, yellow 3-way
connector located at the base of the steering column.
4. Cut the driver inflator module yellow 2-way harness
connector from the
vehicle leaving at least 16 cm(six
inches) of wire at the connector.
5. Strip 13 mm(1/2 inch) of insulation from each wire
lead of the connector.
6. Cut two 900 cm(30 feet) deployment wires from
0.8mm2(18 gauge) or thicker
multi-strand wire. These
wires
will be used to fabricate the driver
deployment harness.
7. Strip 13 mm(1/2 inch) of insulation from both ends of
the wires cut
in the previous step.
8. Short the wires by twisting together one end from
each. Deployment wires
shall remain shorted and
not
be connected to a power source until the air bag
is to be
deployed.
WARNING: FAILURE TO
FOLLOW PROCEDURES
IN
THE ORDER LISTED COULD RESULT IN
PERSONAL INJURY. NEVER CONNECT
DEPLOYMENT WIRES TO ANY POWER SOURCE
BEFORE CONNECTING DEPLOYMENT WIRES TO
THE INFLATOR MODULE LEADS. DEPLOYMENT
WIRES SHALL REMAIN SHORTED AND NOT BE
CONNECTED TO A POWER SOURCE UNTIL THE
AIR BAG IS TO BE DEPLOYED. THE INFLATOR
MODULE WILL IMMEDIATELY DEPLOY THE AIR
BAG WHEN A POWER SOURCE IS CONNECTED TO
IT. WEAR SAFETY GLASSES THROUGHOUT THIS
ENTIRE DEPLOYMENT AND DISPOSAL
PROCEDURE.
9. Twist together one connector wire lead to one
deployment wire. The connection should be
mechanically secure.
10. Bend twisted connection made in the previous step
flat and wrap tightly with electrical tape to insulate ~
and secure.
11. Twist together, bend and tape the remaining
connector wire lead to the remaining deployment
wire.
12. Connect the deployment harness to the driver
inflator module, yellow 2-way connector at the base
of the steering
column. Route deployment harness
out the driver side of the
vehicle.
WARNING:
DEPLOYMENT WIRES SHALL REMAIN
SHORTED
AND NOT BE CONNECTED TO A POWER
SOURCE UNTIL THE AIR BAG IS TO BE DEPLOYED.
THE INFLATOR MODULE WILL IMMEDIATELY
DEPLOY THE AIR BAG WHEN A POWER SOURCE IS
CONNECTED TO IT.
CONNECTING THE DEPLOYMENT WIRES TO THE
POWER
SOURCE SHOULD ALWAYS BE THE FINAL
STEP IN
THE INFLATOR MODULE DEPLOYMENT
PROCEDURE. FAILURE TO FOLLOW
PROCEDURES IN THE ORDER LISTED COULD
RESULT IN PERSONAL INJURY.
13. Disconnect passenger inflator module, yellow 2-way
connector located behind 1/P compartment door
assembly.
14. Cut the passenger inflator module harness
connector from the vehicle leaving at least 16 cm(six
inches) of wire at the connector).

15. Strip 13 mm(1/2 inch) of insulation from each wire
lead of the connector.
16.
Cut two 900 cm(30 feet) deployment wires from
0.8mm2(18 gauge) or thicker multi-strand wire.
These wires
will be used to fabricate the passenger
deployment harness.
17.
Strip 13 mm {1/2inch)of insulation from both ends of
the wires cut in the previous step.
18.
Short the wires by twisting together one end from
each.
Deployment wires shall remain shorted and
not be connected to a power source
until the air bag
is to be deployed.
WARNING: FAILURE TO FOLLOW
PROCEDURES
IN THE ORDER LISTED COULD RESULT IN
PERSONAL INJURY. NEVER CONNECT
DEPLOYMENT WIRES TO ANY POWER SOURCE
BEFORE CONNECTING DEPLOYMENT WIRES TO
THE INFLATOR MODULE LEADS. DEPLOYMENT
WIRES SHALL REMAIN SHORTED AND NOT BE
CONNECTED TO A POWER SOURCE UNTIL THE
AIR BAG IS DEPLOYED? THE INFLATOR MODULE
WILL IMMEDIATELY DEPLOY THE AIR BAG WHEN
A POWER
SOURCE IS CONNECTED TO IT. WEAR
SAFETY GLASSES THROUGHOUT THIS ENTIRE
DEPLOYMENT AND DISPOSAL PROCEDURE.
19. Twist
together one connector wire lead to one
deployment wire. The connection should be
mechanically secure.
20. Bend twisted connection made in the previous step
flat and wrap tightly with electrical tape to insulate
and secure.
21.
Twist together, bend and tape the remaining
connector wire lead to the remaining deployment
wire.
22. Connect the
deployment harness to the passenger
inflator module jumper, yellow 2-way connector
located behind the 1/P compartment door assembly.
Route deployment harness out the passenger side of
the
vehicle.
WARNING:
DEPLOYMENT WIRES SHALL REMAIN
SHORTED
AND NOT BE CONNECTED TO A POWER
SOURCE UNTIL THE AIR BAG IS TO BE DEPLOYED.
THE INFLATOR MODULE WILL IMMEDIATELY
DEPLOY THE AIR BAG WHEN A POWER SOURCE IS
CONNECTED TO IT. CONNECTING THE
DEPLOYMENT WIRES SHOULD ALWAYS BE THE
FINAL STEP IN THE INFLATOR MODULE
DEPLOYMENT PROCEDURE. FAILURE TO
FOLLOW PROCEDURES IN THE ORDER LISTED
COULD RESULT IN PERSONAL INJURY.
23. Verify that the inside of the vehicle and the area
surrounding the
vehicle are clear of all people and
loose or flammable objects.
24.
Stretch the driver and passenger deployment
harnesses to their full length.
Supplemental Restraint System 9J-23
. Completely cover windshield area and front door
window openings with a drop
cloth, blanket or similar
item. This reduced the possibility of injury due to
possible fragmentation of the vehicle's glass or
interior.
26. Notify
all people in the immediate area that you
intend to
deploy the air bags. The deployment will be
accompanied by a
loud noise which may startle the
uninformed.
27.
Separate the two ends of the driver deployment
harness wires.
WARNING: DEPLOYMENT WIRES SHALL REMAIN
SHORTED
AND NOT BE CONNECTED TO A POWER
SOURCE UNTIL THE AIR BAG IS TO BE DEPLOYED.
THE INFLATOR MODULE WILL IMMEDIATELY
DEPLOY THE AIR BAG WHEN A POWER SOURCE IS
CONNECTED TO IT. CONNECTING THE
DEPLOYMENT WIRES TO THE POWER SOURCE
SHOULD ALWAYS BE THE FINAL STEP IN THE
INFLATOR MODUL,E DEPLOYMENT PROCEDURE.
FAILURE TO FOLLOW PROCEDURES IN THE
ORDER LISTED COULD RESULT IN PERSONAL
INJURY.
NOTE: When the air bag deploys, the rapid gas
expansion will create a loud noise. Notify all people in the
immediate area that you intend to
deploy the air bags.
28. Connect the driver
deployment harness wires to a
power source to immediately deploy the driver
inflator module. Recommended application: 12 volts
minimum, 2 amps minimum. A vehicle battery is
suggested.
29.
Separate the two ends of the passenger deployment
harness wires.
WARNING: DEPLOYMENT WIRES SHALL REMAIN
SHORTED
AND NOT BE CONNECTED TO A POWER
SOURCE UNTIL THE AIR BAG IS TO BE DEPLOYED.
THE INFLATOR MODULE WILL IMMEDIATELY
DEPLOY THE AIR BAG WHEN A POWER SOURCE IS
CONNECTED TO IT. CONNECTING THE
DEPLOYMENT WIRES TO THE POWER SOURCE
SHOULD ALWAYS BE THE FINAL STEP IN THE
INFLATOR MODULE DEPLOYMENT PROCEDURE.
FAILURE TO FOLLOW PROCEDURES IN THE
ORDER LISTED COULD RESULT IN PERSONAL
INJURY.
30.
Connectthe passenger deployment harness wires to
a power source to
immediately deploy the passenger
inflator module. Recommended application: 12 volts
minimum, 2 amps minimum. A vehicle battery is
suggested.
After
an inflator module has been deployed, the
surface of the air bag may contain a powdery
residue. This powder consists primarily of cornstarch
(used to lubricate the bag as it inflates) and
byproducts of the chemical reaction. Sodium
hydroxide dust (similar to lye soap) is produced as a
byproduct of the
deployment reaction. The sodium

9J-24 Supplemental Restraint System
hy~roxide th~n quickly reacts with atmospheriC' PROCEDURES COULD RESULT IN PERSONAL
mo1sture and IS converted to sodium carbonate and INJURY.
so~ium bicarbonate (baking soda). Therefore, it is
unlikely that sodium hydroxide will be present after
deployment.
As a precaution, however, gloves and
safety glasses are recommended to prevent any
possible irritation of the skin or eyes.
WARNING: SAFETY PRECAUTIONS MUST BE
OBSERVED WHEN HANDLING A DEPLOYED
INFLATOR MODULE. AFTER DEPLOYMENT, THE
METAL
SURFACES OF THE INFLATOR MODULE
WILL BE VERY HOT. ALLOW THE INFLATOR
MODULE TO COOL BEFORE HANDLING ANY
METAL PORTION OF IT. DO NOT PLACE THE HOT
DEPLOYED INFLATOR MODULE NEAR ANY
FLAMMABLE OBJECTS. FAILURE TO FOLLOW
PROCEDURES COULD RESULT IN FIRE OR
PERSONAL INJURY.
After an inflator module has been deployed, the metal
canister and surrounding areas of the inflator module will
be very hot. Do not touch the metal areas of the inflator
module for about
10 minutes after deployment. If the
deployed inflator module must be moved before it
is cool,
wear gloves
and handle by the air bag or vinyl trim.
31. S~o~t the driver deployment harness wires by
tw1st1ng together one end from each. Repeat this
procedure for the passenger deployment harness.
32. Carefully remove drop cloth from vehicle and clean
off any fragments or discard drop cloth entirely.
33. Disconnect driver deployment harness and
passenger deployment harness from vehicle and
discard.
34.
In the unlikely event that either or both of the inflator
modules did not deploy after following these
procedures, proceed immediately with Steps 36
through
38. If the inflator module deployed proceed
step
35.
35. With both air bags deployed, the vehicle may be
scrapped in the same manner as a non-SRS
equipped vehicle.
NOTE: The remaining steps are to be followed in the
unlikely event that the inflator module did not deploy otter
following these procedures.
36. Remove the undeployed inflator module(s) from the
vehicle. For driver inflator module refer to
in this
section for passenger inflator module
"On-Vehicle
Service".
WARNING:
WHEN STORING A LIVE INFLATOR
MODULE OR WHEN LEAVING A LIVE INFLATOR
MODULE
UNATTENDED ON A BENCH OR OTHER
SURFACE, ALWAYS FACE THE BAG AND TRIM
COVER
UP, AWAY FROM THE SURFACE. THIS IS
NECESSARY SO THAT A FREE SPACE IS
PROVIDED
TO ALLOW THE AIR BAG TO EXPAND IN
THE UNLIKELY EVENT OF ACCIDENTAL
DEPLOYMENT. FAILURE TO FOLLOW
37. Temporarily store the inflator module with the air bag
opening facing
up, away from the surface upon which
it rests.
38. Call the Technical Assistance group for further
assistance.
DEPLOYED INFLATOR MODULE HANDLING
After the inflator module has been deployed, the surface
of the air bag may contain a powdery residue. This
powder
consists primarily of cornstarch (used to
lubricate the bag as it inflates) and byproducts of the
chemical reaction.
Sodium hydroxide dust (similar to lye
soap)
is produced as a byproduct of the deployment
reaction. The sodium hydroxide then quickly reacts with
atmospheric moisture and is converted
to sodium
carbonate and sodium bicarbonate (baking soda}.
Therefore, it
is unlikely that sodium hydroxide will be
present after deployment. As with many service
procedures, you should wear gloves and safety glasses.

, Supplem~l Restraint System
SPECIAL TOOLS
WARNING: TO AVOID DEPLOYMENT WHEN
'-' TROUBLESHOOTING THE SRS, DO NOT USE
ELECTRICAL TEST EQUIPMENT SUCH AS A
BATTERY-POWERED OR AC-POWERED
VOLTMETER, OHMMETER, ETC., OR ANY TYPE OF
ELECTRICAL EQUIPMENT OTHER THAN THAT
SPECIFIED IN THIS MANUAL. DO NOT USE A
NON-POWERED PROBE TYPE TESTER.
INSTRUCTIONS IN THIS MANUAL MUST BE
FOLLOWED CAREFULLY, OTHERWISE PERSONAL
INJURY
MAY RESULT.
SRS DRIVER/PASSENGER LOAD TOOL
The SRS Driver/Passenger Load Tool J-41433 is used
only when called for in this section. It is used as a
diagnostic aid and safety device to prevent inadvertent
inflator
module deployment.
The
load tool has four yellow connectors attached to its
case.
The three
small connectors are electrically functional
and serve as resistive
load substitutions. The large
dummy connector does not serve as a load substitution
but
merely takes the physical place of the DERM
connector when needed.
No more than two connectors are used at any time.
One
of the small connectors is used to substitute for the load
of the driver inflator module when it is connected at the
top of the
column to the SRS coil assembly. Another
small connector is used to substitute for the load of the
driver inflator
module and the SRS coil assembly when
it is connected at the base of the
column to the SRS
wiring harness. The third small connector is used to
substitute for the
load of the passenger inflator module
when connected to the passenger inflator module
harness connector.
By substituting the resistance of the
load tool when called
for, a determination can be made as to whether an
inflator circuit component is causing system malfunction
and which component is causing the malfunction. The
load tool should be used only when specifically called for
in the diagnostic procedures.
9J-25

Suppleme~tralnt System
TABLE OF CONTENTS
SUPPLEMENTAL RESTRAINT SYSTEM
{SRS)
SECTION 2-SYSTEM DIAGNOSIS
9J-27
CAUTION: WHEN FASTENERS ARE REMOVED, ALWAYS REINSTALL THEM AT THE SAME LOCATION
FROM WHICH THEY WERE REMOVED. IF A FASTENER NEEDS TO BE REPLACED, USE THE CORRECT PART
NUMBER
FASTENER FOR THAT APPLICATION. IF THE CORRECT PART NUMBER FASTENER IS NOT
AVAILABLE, A FASTENER OF EQUAL SIZE AND STRENGTH (OR STRONGER) MAY BE USED. FASTENERS
THAT ARE NOT REUSED, AND THOSE REQUIRING THREAD LOCKING COMPOUND WILL BE CALLED OUT.
THE CORRECT TORQUE VALUE
MUST BE USED WHEN INSTALLING FASTENERS THAT REQUIRE IT. IF THE
ABOVE CONDITIONS ARE NOT FOLLOWED, PARTS OR SYSTEM DAMAGE COULD RESULT.
HOW TO USE THIS SECTION . . . . . . . . • . . . . . . . . . . . • . . . . . . . . . • • • • • • . • . • • . . . . . • • . 30
Diagnostic Procedures • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
Diagnostic Codes • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
How to Read Trouble Codes • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
How to Clear Trouble Codes • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
Scan
Tool Diagnostics • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
Basic Knowledge Required • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
Basic Electrical Circuits • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
"Flash Code"
Diagnostics • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30
SYSTEM SCHEMATIC . . • . • . . . . • • • • • • • • . • . . • . . • . • • . • • • . . . • • . . . . . . . • • . . • • • • • • • 31
SRS DIAGNOSTIC SYSTEM CHECK • . • • • . • • . • . . . . . • . • . • . • • • . . . • . • . . • . . . . . . . • . 32
,_.., TABLE A DERM INTEGRITY CHECK • . • • • . . . . . . . . . . • . • • • . • • • . • • . • . . . • . . . . . . . . . 34
TABLE B "AIR BAG" WARNING LAMP COMES "ON" STEADY . . . . . . . . . . . . . . . . • . 36
TABLE C "AIR BAG" WARNING LAMP DOES NOT COME "ON" . . . . . . . . . . . . . . . • . 38
TABLED "AIR BAG" WARNING LAMP DOES NOT COME "ON" STEADY DURING
CRANK .......................................................... .
DTC 14 DUAL POLE ARMING SENSOR DISCONNECTED ..•.••••••.•...........
DTC 15 PASSENGER INITIATOR CIRCUIT RESISTANCE HIGH •.................
DTC 16 PASSENGER INITIATOR CIRCUIT RESISTANCE LOW ...........•...••..
DTC 17 PASSENGER INITIATOR CIRCUIT OPEN ..••.•.......•.•••...•......••.
DTC 18 DISCRIMINATING SENSOR INTERCONNECT OPEN ................... .
DTC
19 PASSENGER INITIATOR CIRCUIT VOLTAGE HIGH •....•.....••.•..•.•..
DTC 21 DRIVER INITIATOR CIRCUIT RESISTANCE HIGH
DTC 22 DRIVER INITIATOR CIRCUIT RESISTANCE LOW ..••••.••.•.••..•.•.•••
DTC 23 DRIVER INITIATOR CIRCUIT VOLTAGE HIGH ........................•.
DTC 24 INITIATOR CIRCUIT VOLTAGE LOW .....••....•..•...•................
DTC 25 INITIATOR CIRCUIT SHORT TO IGNITION .............•.............•..
DTC 26 DRIVER INITIATOR CIRCUIT OPEN •.••........................••..•.••
DTC 28 CURRENT SINK OR SOURCE FAILURE ............................... .
DTC 31 DRIVER LOOP ENERGY RESERVE FEED OPEN ....................... .
40
42
44
46
48
50
52
54
56
58
60
66
70
72
74

9J-30 Supplemental Restraint System (SRS)

HOW TO USE THIS SECTION
DIAGNOSTIC PROCEDURES
WARNING: TO AVOID DEPLOYMENT WHEN
TROUBLESHOOTING THE SRS, DO NOT USE
ELECTRICAL TEST EQUIPMENT SUCH AS A
BATTERY-POWERED OR AC-POWERED
VOLTMETER, OHMMETR,ETC. ,OR ANY TYPE OF
ELECTRICAL EQUIPMENT OTHER THAN THAT
SPECIFIED IN THIS MANUAL. DO NOT USE A
NON-POWERED PROBE TYPE TESTER.
INSTRUCTIONS IN THIS MANUAL MUST BE
FOLLOWED CAREFULLY, OTHERWISE PERSONAL
INJURY
MAY RESULT.
The diagnostic procedures used in this section are
designed to aid
in finding and repairing SRS problems.
Outlined below
are the steps to find and repair SRS
problems quickly
and effectively. Failure to carefully
follow these procedures may result in extended
diagnostic time, incorrect diagnosis and incorrect parts
replacement.
1. Perform the "SRS Diagnostic System Check". The
"SRS Diagnostic System Check" should always be
the starting point of any SRS diagnostics. The "SRS
Diagnostic System Check" checks for proper "AIR
BAG" indicator operation and checks for SRS trouble
codes using both "Flash Code" and "Scan Tool"
Methods.
2. 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 problems. Bypassing
these procedures may
result in extended diagnostic
time, incorrect diagnosis and incorrect parts
replacement.
3. Repeat the "SRS Diagnostic System Check" after
any repair
or diagnostic procedures have been
performed.Performing the
"SRS Diagnostic System
Check" after all repair or diagnostic procedures will
assure that the repair has been made correctly and
that no other conditions exist.
DIAGNOSTIC CODES
The Diagnostic Energy Reserve Module (DERM)
maintains a history record of all diagnostic codes that
have been detected since the
SRS codes were last
cleared
during service.
1. Current Codes -Faults that are presently detected
this ignition
cycle. Active and Cycle codes are stored
in RAM (Random Access Memory).
2. History
Codes-All faults detected since the last time
the history
fault memory was cleared. History codes
are stored in EEPROM (Electrically Erasable
Programmable Read Only Memory )
HOW TO READ TROUBLE CODES
All codes (Active cycle and history) can be read (or
cleared) by using a Scan Tool (Portable Diagnostic Tool
[PDT)) or equivalent. If a PDT is not available, have the
vehicle serviced by a Saturn Dealer.
HOW TO CLEAR TROUBLE CODES
Trouble codes can only be cleared by using a Scan Tool.
If
a "Scan Tool" is not available, then inform the owner of
the stored codes and suggest that the codes are
cleared
upon the next visit to a ISUZU dealership.
SCAN TOOL DIAGNOSTICS
A Scan Tool can be used to read current and history
codes and to
clear all history codes after a repair is
complete. The scan tool must be updated to
communicate with the
SRS through a replaceable
cartridge or a manufacturer's update before it can be
used for
SRS diagnostics. To use the scan tool, connect
it to the ALDL connector and turn the ignition switch
"ON". Then follow the manufacturer's directions for
communication with the
SRS. The scan tool reads serial
data from the DERM "Serial Data" output (terminal A 11)
to the ALDL connector (terminal M) Via ISUZU
Convertible Connector (terminal 2).
BASIC KNOWLEDGE REQUIRED
Before using this section of the Service Manual, there is
some basic
knowledge which will be required. Without
this knowledge, you
will have trouble using the diagnostic
procedures
in this section. Use care to prevent harm or
unwanted
deployment. Read all cautions in the service
manual and on warning labels attached to SRS
components.
BASIC ELECTRICAL CIRCUITS
You should understand the basic theory of electricity
including series and parallel circuits, and understand the
voltage drops across series resistors. You should know
the meaning of
voltage (volts), current (amps), and
resistance (ohms). You should understand what
happens in a circuit with an open or a shorted wire. You
should be able to read and understand a wiring diagram.
"FLASH CODE" DIAGNOSTICS
"Flash Code" diagnostics are not implemented for SRS
diagnostic on TROOPER(UX)Vehicles.

Supplemental Restraint System

SYSTEM SCHEMATIC
TO IGNITION-----,
TO DRIVER 36VLR
SWITCH ,.--Ji........,--L--r-1----,
TO PASSENGER 36VLR
TO PASSENGER SOURCE
SENSE
DUAL POLE ARMING SENSOR
JOINT CONNECTION
'-----+---.--+---TO
PASSENGER INFLATOR
MODULE
1-----.-TO DERM 83
JOINT CONNECTION LOW PRESSURE WARNING SENSOR
LH FORWARD DISCRIMINATING
SENSOR
DERM PASSENGER
SIDE HIGH
TO IGNITION
SWITCH
TO
DERM DRIVER SIDE
HIGH
TO
DERM PASSENGER
SIDE LOW
TO
DERM DRIVER
SIDE LOW RH FORWARD DISCRIMINATING
SENSOR
9J-31

9J-32 Supplemental Restraint System (SRS)
SRS DIAGNOSTIC SYSTEM CHECK
WARNING: TO AVOID DEPLOYMENT WHEN
TROUBLESHOOTING THE SRS, DO NOT USE
ELECTRICAL TEST EQUIPMENT SUCH AS A
BATTERY-POWERED OR AC-POWERED
VOLTMETER, OHMMETER, ETC., OR ANY TYPE OF
ELECTRICAL EQUIPMENT OTHER THAN THAT
SPECIFIED IN THIS MANUAL. DO NOT USE A
NON-POWERED PROBE TYPE TESTER.
INSTRUCTIONS IN THIS MANUAL MUST BE
FOLLOWED CAREFULLY, OTHERWISE PERSONAL
INJURY
MAY RESULT.
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
DERM 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 PERFORMED.
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-22·C-23" fuse to the
DERM at the
"Ignition 1" input terminals "A9" and "A10"
and from the "C-21" fuse to the DERM at the "Redundant
Indicator Ignition 1" input terminal "B2". The DERM
responds by flashing the
"AIR BAG" warning lamp seven
times while performing tests on the
SRS.When the
engine is being cranked,
"Starter'' voltage is applied from
the
"C-1" fuse to the DERM at the "Crank" input terminal
"B10".The DERM responds by grounding the "SRS
Indicator"
output terminal "B 1" until "Starter" voltage is
removed from the "Crank" input. This results in the "AIR
BAG" warning lamp being "ON" steady during
cranking.After cranking, the DERM will flash the "AIR
BAG"
warning lamp six times and perform tests on the
SRS.
NOTES ON SYSTEM CHECK CHART ~
1. The "AIR BAG" warning lamp should flash seven
times after ignition is first turned
"ON."
2. The "AIR BAG" warning lamp should remain "ON"
steady during cranking.
3. When the "AIR BAG" warning lamp flashes four
times during
"Bulb Check" this indicates a
malfunction
in the redundant lamp driver circuitry.
These malfunctions are diagnosed by
DTC 62 chart.
4. After cranking, the "AIR BAG" warning lamp should
flash six times then go
"OFF."
5. 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.
6. 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.
7. 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
diagnostic trouble codes in the order specified may result
in extended diagnostic time, incorrect diagnosis and
incorrect parts replacement.

Supplemental Restraint System 9J-33
SRS DIAGNOSTIC SYSTEM CHECK
STEP
ACTION YES NO
1 NOTE "AIR BAG" WARNING LAMP AS IGNITION SWITCH IS GOTOSTEP2 GOTOSTEP3 TURNED "ON."
DOES WARNING
LAMP FLASH 7 TIMES?
2 NOTE "AIR BAG" WARNING LAMP AS ENGINE IS STARTED. GOTOSTEP4 GO TO CHART D. DOES WARNING LAMP COME "ON" STEADY DURING
CRANKING?
3 DOES WARNING LAMP FLASH 4 TIMES? GOTO DTC62. GO TO STEPS.
4 NOTE "AIR BAG" WARNING LAMP AFTER STARTING. GOTOSTEP6 GOTOSTEP7 DOES WARNING LAMP FLASH 6 TIMES THEN GO "OFF"?
5 DOES WARNING LAMP COME "ON" STEADY? GO TO CHART B. GO TO CHART C.
6 IGNITION SWITCH "OFF." IF
NO SRS DIAGNOSTIC TROUBLE CODES
CONNECT SCAN TOOL TO
DATA LINK CONNECTOR, ARE DISPLAYED. GOTO STEP 8. FOLLOW DIRECTIONS AS GIVEN IN THE SCAN TOOL
INSTRUCTION MANUAL.
IGNITION SWITCH "ON."
IF HISTORY DIAGNOSTIC TROUBLE CODES
REQUEST SRS DIAGNOSTIC TROUBLE CODE DISPLAY, ARE DISPLAYED. GOTO STEP 9. RECORD ALL HISTORY DIAGNOSTIC TROUBLE CODES,
SPECIFYING AS SUCH, ON REPAIR ORDER.
7 IGNITION SWITCH "OFF." IF DIAGNOSTIC TROUBLE CODES ARE
CONNECT SCAN TOOL TO DATA LINK CONNECTOR, DISPLAYED. GOTO STEP 10. FOLLOW DIRECTIONS AS GIVEN IN THE SCAN TOOL
INSTRUCTION MANUAL. IGNITION SWITCH "ON."
REQUEST SRS DIAGNOSTIC
TROUBLE CODE DISPLAY, RECORD ALL DIAGNOSTIC TROUBLE CODES SPECIFYING
AS CURRENT OR HISTORY ON REPAIR ORDER.
8
SRS IS FUNCTIONAL AND FREE OF MALFUNCTIONS.
NO FURTHER DIAGNOSIS IS REQUIRED.
9 IGNITION SWITCH "OFP'. WHEN DTC 83 IS SET, GO TO DTC 83 CHART. WHEN DTC 84 IS SET, GO TO DTC 84 CHART. FOR ALL OTHER HISTORY DIAGNOSTIC TROUBLE CODES, REFER TO "DIAGNOSTIC AIDS" FOR THAT
SPECIFIC DIAGNOSTIC TROUBLE CODE. A HISTORY DTC INDICATES THE MALFUNCTION HAS BEEN REPAIRED OR IS INTERMITTENT.
10 DIAGNOSTIC
TROUBLE CODES ARE DISPLAYED.
IGNITION SWITCH "OFF."
WHEN DTC 51 IS SET, GO TO DTC 51 CHART. DIAGNOSE REMAINING CURRENT DIAGNOSTIC TROUBLE CODES FROM LOWEST TO HIGHEST. WHEN ONLY HISTORY DIAGNOSTIC TROUBLE CODES EXIST, REFER TO "DIAGNOSTIC AIDS" FOR THAT SPECIFIC DIAGNOSTIC TROUBLE CODE. A HISTORY DTC INDICATES THE MALFUNCTION
HAS BEEN
REPAIRED OR IS INTERMITTENT.

9J-34 Supplemental Restraint System
TABLE A
DERM INTEGRITY CHECK
CIRCUIT DESCRIPTION
When the DERM recognizes "Ignition 1" voltage, applied
to terminals "A9" and "A10", is in the normal operating
voltage range, the "AIR BAG" warning lamp is flashed 7
timestoverifyoperation. At this time the DERM performs
"Turn-ON" tests followed by "Continuous Monitoring"
tests. When no malfunctions are detected the DERM
proceeds to the
"Initiator Assembly Resistance Test."
When a malfunction
is detected the DERM sets a current
diagnostic
trouble code and illuminates the "AIR BAG"
warning lamp. The DERM will clear current diagnostic
trouble codes and move them to a history file when the
malfunction is no
longer detected and/or the ignition
switch is
cycled, except for DTC 51. DTC 51 can only be
cleared using a scan tool "Clear Codes" command.
TO IGNITION SWITCH
FUSEl SRS C-24 lOA .... R D
CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic table.
1. This test confirms a current malfunction. If no current
malfunction is occurring(history DTC set) the
"Diagnostic Aids" for the appropriate diagnostic
trouble code should be referenced. The DERM
should not be replaced for a history diagnostic
trouble code.
2. This test checks for a malfunction introduced into the
SRS during the diagnostic process. It is extremely
unlikely
that a malfunctioning DERM would cause a
new malfunction to occur during the diagnostic
process.
3. When all circuitry outside the DERM has been found
to operate
properly, as indicated by the appropriate
diagnostic chart, then and
only then should the
DERM be
replaced.
IGNITION!
IGNITION
1
DRIVER 36VLR PASS.36VLR PASS. SOURCE SENSE
PASS SlOE HIGH
PASS SIDE LOW
SPARE/LPS
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