2004 ISUZU TF SERIES torque

9A-4 SUPPLEMENTAL RESTRAINT SYSTEM

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, REFE
R
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, o
r
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.
General Description
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 fo
r
that application. If the correct part numbe
r
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.


Restraint Devices
827RW006
Legent
(1) Deployed Air Bag
(2) Knee Bolster
(3) Seat Belt


The Supplemental Restraint System (SRS) helps
supplement the protection offered by the driver and
front passenger seat belts by deploying an air bag
from the center of the steering wheel and from the
front of the passenger side of the instrument panel.
The air bag deploys when the vehicle is involved in a
frontal crash of sufficient force up to 30 degrees off the
centerline of the vehicle. To further absorb the crash
energy there is a knee bolster located beneath the
instrument panel for both the driver and passenger,
and the steering column is collapsible.

827RW005

9A-8 SUPPLEMENTAL RESTRAINT SYSTEM

The SRS control unit is connected to the SRS wiring
harness by a 52–pin connector. This harness
connector uses a shorting clip across certain terminals
in the contact area. This shorting clip connects the
“AIR BAG” warning lamp to ground when the SRS
control unit harness connector is disconnected or CPA
(Connector Position Assurance) is not inserted even if
completely connected. This will cause the “AIR BAG”
warning lamp to come “ON” steady whenever the
ignition switch is at the ON or START positions with
the SRS control unit disconnected.


060R300008
Legent
(1) SRS Control Unit
(2) SRS Harness
(3) Connector Position Assurance

Component Description
SRS Control Unit
WARNING: DURING SERVICE PROCEDURES, BE
VERY CAREFUL WHEN HANDLING A SRS
CONTROL UNIT NEVER STRIKE OR JAR THE SRS
CONTORL UNIT. NEVER POWER UP THE SRS
WHEN THE SRS CONTROL UNIT IS NOT RIGIDLY
ATTACHED TO THE VEHICLE. ALL SRS
CONTROL UNIT AND MOUNTING BRACKET
FASTENERS MUST BE CAREFULLY TORQUED
AND THE ARROW MUST BE POINTED TOWARD
THE FRONT OF THE VEHICLE TO ENSURE
PROPER OPERATION OF THE SRS. THE SRS
CONTROL UNIT COULD BE ACTIVATED WHEN
POWERED WHILE NOT RIGIDLY ATTACHED TO
THE VEHICLE WHICH COULD CAUSE
DEPLOYMENT AND RESULT IN PERSONAL
INJURY.
The SRS control unit is designed to perform the
following functions in the SRS:
1. Energy Reserve — The SRS control unit maintains
24–
Volt Loop Reserve (24VLR) energy supply to
provide deployment energy when ignition voltage is
lost in a frontal crash.
2. Frontal Crash Detection — The SRS control uni
t
monitors vehicle velocity changes to detect frontal
crashes which are severe enough to warran
t
deployment.
3. Air Bag Deployment — When a frontal crash o
f
sufficient force is detected, the SRS control unit
will cause enough current to flow through the air
bag assembly to deploy the air bag.
4. Malfunction Detection —The SRS control uni
t
performs diagnostic monitoring of SRS electrical
components and sets a diagnostic trouble code
when a malfunction is detected.
5. Frontal Crash Recording — The SRS control uni
t
records information regarding SRS status during
frontal crash.
6. Malfunction Diagnosis —The SRS control uni
t
displays SRS diagnostic trouble codes and system
status information through the use of a scan tool.
7. Driver Notification — The SRS control unit warns
the vehicle driver of SRS malfunctions b
y
controlling the “Air Bag” warning lamp.




“Air Bag” Warning Lamp
Ignition voltage is applied to the “AIR BAG” warning
lamp when the ignition switch is at the ON or START
positions. The SRS control unit controls the lamp by
providing ground with a lamp driver. The “AIR BAG”
warning lamp is used in the SRS to do the following:
1.
Verify lamp and SRS control unit operation by
flashing SEVEN (7) times when the ignition switch
is first turned “ON”.
2. Warn the vehicle driver of SRS electrical system
malfunctions which could potentially affect the
operation of the SRS. These malfunctions could
result in nondeployment in case of a frontal crash
or deployment for conditions less severe than
intended.
The “AIR BAG “ warning lamp is the key to driver
notification of SRS malfunctions. For proper lamp
operation, refer to the “SRS Diagnostic System Check”
in this section.

SUPPLEMENTAL RESTRAINT SYSTEM 9A-27

Service Precautions for SRS
Component Service
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 fo
r
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.
WARNING: WHEN PERFORMING SERVICE ON O
R
AROUND SRS COMPONENTS OR SRS WIRING,
FOLLOW THE PROCEDURES LISTED BELOW TO
TEMPORARILY DISABLE THE SRS. FAILURE TO
FOLLOW PROCEDURES COULD RESULT IN
POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY OR OTHERWISE UNNEEDED SRS
REPAIRS.
The SRS control unit in Driver–Passenger SRS can
maintain sufficient voltage to cause a deployment for
up to 15 seconds after the ignition switch is turned
“OFF,” the battery is disconnected, or the fuse
powering the SRS control unit is removed.
Many of the service procedures require removal of the
“SRS” fuse, and disconnection of the air bag assembly
from the deployment loop to avoid an accidental
deployment. If the air bag assembly is disconnected
from the deployment loop as noted in the “Disabling
the SRS” procedure that follows, service can begin
immediately without waiting for the 15 second time
period to expire.

Disabling The SRS
Removal
Turn the ignition switch to “OFF” and turn the steering
wheel so that the vehicle's wheels are pointing straight
ahead.
1. Remove SRS fuse “SRS” from left dash side lowe
r
fuse block or disconnect battery.
2. Disconnect yellow connector at the base o
f
steering column.
3. Remove glove box assembly; Refer to “Passenge
r
air bag assembly replacement” in this section.
4. Disconnect passenger air bag assembly yello
w
connector behind the glove box assembly.
CAUTION: With the “SRS” fuse removed and
ignition switch “ON,” the “AIR BAG” warning lamp
will be “ON.” This is normal operation and does
not indicate an SRS malfunction.
Enabling The SRS
Installation
Turn ignition switch to “LOCK” and remove key.
1. Connect yellow connector passenger air bag
assembly.
2. Install glove box assembly. Refer to “Passenge
r
Air Bag Assembly Replacement” in this section.
3. Connect yellow connector at the base of the
steering column.
4. Install “AIR BAG” fuse “SRS” to left dash side
lower fuse block or connect battery.
Turn ignition switch to “ON” and verify that the “AIR
BAG” warning lamp flashes seven times and then
turns “OFF.” If it does not operate as described,
perform the “SRS Diagnostic System Check” in this
section.

Handling / Installation / Diagnosis
1. Air bag assembly should not be subjected to
temperatures above 65

C (150

F).
2. Air bag assembly, and SRS control unit should not
be used if they have been dropped from a height
of 100 centimeters (3.28 feet) or more.
3. When a SRS control unit is replaced, it must be
oriented with the arrow on the SRS control unit
pointing toward the front of the vehicle. It is ver
y
important for the SRS control unit to be located flat
on the mounting surface, parallel to the vehicle
datum line. It is important that the SRS control unit
mounting surface is free of any dirt or other foreign
material.
4. Do not apply power to the SRS unless all
components are connected or a diagnostic chart
requests it, as this will set a diagnostic trouble
code.
5. The “SRS Diagnostic System Check” must be the
starting point of any SRS diagnostics. The “SRS
Diagnostic System Check” will verify proper “AIR
BAG” warning lamp operation and will lead you to
the correct chart to diagnose any SRS
malfunctions. Bypassing these procedures ma
y
result in extended diagnostic time, incorrect
diagnosis, and incorrect parts replacements.

Inspections Required After An Accident
CAUTION: Certain SRS components must be
replaced after a frontal crash involving air bag
deployment.
In all types of accidents regardless of “Air Bag”
deployment, visually inspect all of the following
components and replace as required:

9A-30 SUPPLEMENTAL RESTRAINT SYSTEM

SRS Control Unit
5. Remove the three SRS control unit fixing bolts and
remove SRS control unit.


RTW49JSH000101
Legent
(1) SRS control unit
(2) SRS Harness
(3) Connector Position Assurance

Service Precautions
WARNING: DURING SERVICE PROCEDURES, BE
VERY CAREFUL WHEN HANDLING SRS control
unit. NEVER STRIKE OR JAR SRS control unit.
UNDER SOME CIRCUMSTANCES, IT COULD
CAUSE DEPLOYMENT AND RESULT IN
PERSONAL INJURY OR IMPROPER OPERATION
OF THE SUPPLEMENTAL RESTRAINT SYSTEM
(SRS) . SRS control unit MOUNTING BRACKET
BOLTS MUST BE CAREFULLY TORQUED TO
ASSURE PROPER OPERATION. NEVER POWE
R
UP THE SRS WHEN SRS control unit IS NOT
RIGIDLY ATTACHED TO THE VEHICLE. THE SRS
control unit COULD BE ACTIVATED WHEN
POWERED WHILE NOT RIGIDLY ATTACHED TO
THE VEHICLE WHICH COULD CAUSE
DEPLOYMENT AND RESULT IN PERSONAL
INJURY.
WARNING: PROPER OPERATION OF THE SRS
CONTROL UNIT REQUIRES THE SRS CONTROL
UNIT TO BE RIGIDLY ATTACHED TO THE
VEHICLE STRUCTURE AND THAT THE ARROW
ON THE SENSOR BE POINTING TOWARD THE
FRONT OF THE VEHICLE.
SRS control unit is specifically calibrated and is keyed
to the SRS control unit location SRS wiring harness.
Caution should be used to ensure proper location of
the SRS control unit. The keying of the SRS control
unit to its location and wiring harness connectors
should never be modified in the field.

Removal
1. Disable the SRS (Refer to “Disabling the SRS” in
this section).
2. Remove the transmission knob (for M/T) and
transfer lever knob.
3. Remove the front console assembly and
disconnect wiring harness connector.
4. Pull CPA (Connector Position Assurance) out and
push connector lock down to disconnect the SRS
control unit harness connector.

Installation
1. Install the SRS control unit on bracket and fixing
bolts and tighten the fixing bolts to the specified
torque.
Torque: 7




2 N
 m (0.7




0.2 kg
 m/61 lb in)
2. Connect the SRS control unit harness connecto
r
and after that, put CPA into connector.
3. Install the front console.
4. Install the transmission knob (for M/T) and transfe
r
lever knob.

9A-36 SUPPLEMENTAL RESTRAINT SYSTEM

Installation
1. Install the steering wheel and align the setting
marks.
060R300024
NOTE: Confirm SRS and Horn harness connector is
fixed by the steering wheel.
RTW33BSH000601
2. Tighten the steering wheel fixing nut to the
specified torque.
Torque : 34 N




m (3.5 kg




m/25 lb ft)
3. Install the SRS air bag assembly. (Refer to “Drive
r
Air Bag Assembly” in this section)

SUPPLEMENTAL RESTRAINT SYSTEM 9A-39

NOTE: Confirm SRS and Horn harness connector is
fixed by the steering wheel.
RTW33BSH000601
9. Tighten the steering wheel fixing nut to the
specified torque.
Torque: 35 N




m (3.5 kg




m/25 lb ft)
10. Install the SRS air bag assembly. (Refer to “Drive
r
Air Bag Assembly in this section).

SUPPLEMENTAL RESTRAINT SYSTEM 9A-41

7. Remove the driver knee bolster assembly.


RTW49JSH000401
Legend
(1) RHD
(2) LHD

8. Remove the steering column cover.
9. Disconnect the wiring harness connectors located
at the base of steering column.
CAUTION: Never apply force to the steering wheel
in direction of the shaft by using a hammer o
r
other impact tools in an attempt to remove the
steering wheel. The steering shaft is designed as
an energy absorbing unit.
10. Remove the combination switch assembly with
SRS coil.
SRS coil is a part of combination switch assembly,
which cannot be replaced separately. Therefore, be
sure not to remove the SRS coil from the combination
switch assembly.
11.Remove the snap ring.
12. Remove the cushion rubber.
13. Disconnect shift lock cable (A/T only).
14.Disconnect the starter switch harness connecto
r
located base of steering column.
15. Remove steering lock cylinder assembly.



16.Apply a setting mark across the universal joint and
steering shaft to reassemble the parts in thei
r
original position.
060R300038
17.Remove steering column assembly.

Installation
1. Install the steering column assembly and align the
setting marks on the universal joint and steering
shaft made during removal.
060R300038
2. Tighten the steering column fixing bolts (dash
panel side) to the specified torque.
Torque: 20 N




m (2.0 kg




m/14 lb ft)
3. Tighten the steering column fixing bolts (Pedal
bracket) to the specified torque.
Torque: 20 N





m (2.0 kg





m/14 lb ft)

9A-42 SUPPLEMENTAL RESTRAINT SYSTEM

4. Tighten the universal joint to the specified torque.
Torque: 31 N




m (3.2 kg




m/23 lb ft)
5. Install steering lock cylinder assembly.
6. Connect shift lock cable (For A/T)
7. Install cushion rubber.
8. Install snap ring.
9. Install the combination switch assembly with SRS
coil.
10. Connect the wiring harness connector located on
the base of steering column.
11. Turn the SRS coil counterclockwise to full, return
about 3 turns and align the neutral mark.
CAUTION: When turning the SRS coil
counterclockwise to full, stop turning if resistance
is felt. Forced further turning may damage to the
cable in the SRS coil.
826RW014
Legend
(1) Neutral mark

12.Install steering column cover.
CAUTION: When installing the steering column
cover, be sure to wire (through each harness) as
illustrated so that the harness starter switch,
combination switch and SRS coil may not catch
wiring.


825RS048
13.Install the steering wheel and align the setting
marks.