Isuzu Trooper (2000 year). Manual - part 526

SUPPLEMENTAL RESTRAINT SYSTEM

9J–41

Passenger Air Bag Assembly

Service Precautions

WARNING: SAFETY PRECAUTIONS MUST BE
FOLLOWED WHEN HANDLING A DEPLOYED AIR
BAG ASSEMBLY. AFTER DEPLOYMENT, THE AIR
BAG ASSEMBLY SURFACE MAY CONTAIN A SMALL
AMOUNT OF SODIUM HYDROXIDE, A BY–PRODUCT
OF THE DEPLOYMENT REACTION, THAT IS
IRRITATING TO THE SKIN AND EYES. MOST OF THE
POWER ON THE AIR BAG ASSEMBLY IS
HARMLESS. AS A PRECAUTION, WEAR GLOVES
AND SAFETY GLASSES WHEN HANDLING A
DEPLOYED AIR BAG ASSEMBLY, AND WASH YOUR
HANDS WITH MILD SOAP AND WATER
AFTERWARDS.

WARNING: WHEN CARRYING A LIVE AIR BAG
ASSEMBLY, MAKE SURE THE BAG AND TRIM
COVER ARE POINTED AWAY FROM YOU. NEVER
CARRY AIR BAG ASSEMBLY BY THE WIRES OR
CONNECTOR ON THE UNDERSIDE OF MODULE. IN
THE CASE OF AN ACCIDENTAL DEPLOYMENT, THE
BAG WILL THEN DEPLOY WITH MINIMAL CHANCE
OF INJURY. WHEN PLACING ALIVE AIR BAG
ASSEMBLY ON A BENCH OR OTHER SURFACE,
ALWAYS FACE BAG AND RIM COVER UP, AWAY
FROM THE SURFACE. NEVER REST A STEERING
COLUMN ASSEMBLY ON THE STEERING WHEEL
WITH THE AIR BAG ASSEMBLY FACE DOWN AND
COLUMN VERTICAL. THIS IS NECESSARY SO THAT
A FREE SPACE IS PROVIDED TO ALLOW THE AIR
BAG ASSEMBLY TO EXPAND IN THE UNLIKELY
EVENT OF ACCIDENTAL DEPLOYMENT.
OTHERWISE, PERSONAL INJURY COULD RESULT.

NOTE:  IN THE EVENT DEPLOYMENT HAS
OCCURRED, INSPECT COIL ASSEMBLY WIRE FOR
ANY SIGNS OF SCORCHING, MELTING OR ANY
OTHER DAMAGE DUE TO EXCESSIVE HEAT. IF THE
COIL HAS BEEN DAMAGED, REPLACE IT.

Removal

827RS001

1. Disable the SRS (Refer to “Disabling the SRS ” in this

section).

2. Remove gear control knob.
3. Remove front console assembly.
4. Remove rear console assembly and disconnect

harness connector.

5. Remove ECM and SDM cover.
6. Remove glove box assembly with lid.
7. Remove glove box cover.
8. Remove instrument panel assist side lower cover.
9. Disconnect engine hood opener lever.

10. Remove instrument panel door side lower cover.

11. Remove lower cluster with ashtray.

12. Remove meter cluster assembly and disconnect

harness connector.

13. Remove instrument panel lower center cover.
14. Disconnect passenger air bag assembly harness

connector.

15. Remove air bag assembly fixing bolts and nuts.
16. Remove passenger air bag assembly.

SUPPLEMENTAL RESTRAINT SYSTEM

9J–42

Installation

827RS001

1. Install passenger air bag assembly.

2. Install air bag assembly fixing nuts and tighten to

specified torque.

Torque: 6 N·m (52 lb in)

3. Connect air bag assembly harness connector.
4. Install instrument panel lower center cover.
5. Install meter cluster assembly and connect harness

connector.

6. Install lower cluster with ashtray.
7. Install instrument panel door side lower cover.
8. Connect engine hood opener lever.
9. Install instrument panel assist side lower cover.

10. Install glove box cover.

11. Install glove box assembly with lid.

12. Install ECM and SDM cover.
13. Install rear console assembly and connect harness

connector.

14. Install front console assembly.
15. Install gear control knob.
16. Enable the SRS (Refer to “Enabling the SRS” in this

section).

Main Data and Specifications

Fastener Tightening Specification

Application

N·m

Lb Ft

Lb In.

SDM

10

—

87

Driver air bag fixing bolt

8.8

—

78

Steering wheel fixing bolt

34

25

—

Steering column (dash panel side fixing bolts)

20

14

—

Steering column (Pedal bracket fixing bolt)

20

14

—

Steering column (Universal joint fixing bolt)

31

23

—

Passenger Air Bag fixing nuts

6

—

52

9J1–1

RESTRAINT CONTROL SYSTEM

Trooper

RESTRAINTS

RESTRAINT CONTROL SYSTEM

CONTENTS

Service Precaution

9J1–1

. . . . . . . . . . . . . . . . . . . . . . 

Diagnostic Information

9J1–2

. . . . . . . . . . . . . . . . . . . 

System Schematic

9J1–4

. . . . . . . . . . . . . . . . . . . . . . 

SRS Diagnostic System Check

9J1–4

. . . . . . . . . . . . 

Chart A  SDM Integrity Check

9J1–6

. . . . . . . . . . . . . 

Chart B  “AIR BAG” Warning Lamp
 Comes “ON” Steady

9J1–8

. . . . . . . . . . . . . . . . . . . . 

Chart C  “AIR BAG” Warning Lamp Does
 Not Come “ON” Steady (1/2) 

9J1–10

. . . . . . . . . . . . . 

DTC 15  Passenger Deployment Loop
 Resistance High

9J1–13

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 16  Passenger Deployment loop
 Resistance Low

9J1–15

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 17  Passenger Deployment Loop
 Open

9J1–17

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

DTC 18  Passenger Deployment Loop
 Short To Ground

9J1–19

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 19  Passenger Deployment Loop
 Short To Voltage

9J1–21

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 21  Driver Deployment Loop
 Resistance High

9J1–23

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 22  Driver Deployment Loop
 Resistance Low

9J1–26

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 24  Driver Deployment Loop
 Short To Ground

9J1–28

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 25  Driver Deployment Loop
 Short To Voltage

9J1–30

. . . . . . . . . . . . . . . . . . . . . . . . 

DTC 26  Driver Deployment Loop Open

9J1–32

. . . . 

DTC 51  Deployment Event Commanded

9J1–34

. . . 

DTC 53  Deployment Commanded With
 Deployment Loop Fault Or Energy
 Reserves Out Of Range

9J1–36

. . . . . . . . . . . . . . . . . 

DTC 61  Warning Lamp Circuit Failure

9J1–38

. . . . . 

DTC 71  Internal SDM Fault

9J1–40

. . . . . . . . . . . . . . 

Service Precaution

WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING, REFER TO
THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN POSSIBLE
AIR BAG DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

RESTRAINT CONTROL SYSTEM

9J1–2

Diagnostic Information

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.

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, 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 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” warning lamp 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.
Preforming 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 Sensing and Diagnostic Module (SDM) maintains a
history record of all diagnostic codes that have been

detected since the SRS codes were last cleared during
service.

1. Active Codes — Faults that are presently detected

this ignition cycle.  Active 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. (Electronically
Erasable Programmable Read only Memory) 

How To Read Trouble Codes 

All codes (Active and history) can be read (or cleared) by
using a scan tool or equivalent.
If a PDT is not available, have the vehicle serviced by
ISUZU 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 an 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 DLC 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 SDM “Serial Data” output
(terminal 24) to the DLC connector (terminal 9).

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 can be used to read active codes
and to determine if history codes are present but cannot
be used to clear codes or read history codes. Flash code
diagnostics is enabled by grounding by terminal 4
shorting to terminal 13 of the DLC connector with the
ignition switch “ON”. Grounding terminal 4 of the DLC
connector pulls the “Diagnostics Request” input (Terminal
1) of the SDM low and signals the SDM to enter the flash
code diagnostic display mode.