steering ISUZU TF SERIES 2004 User Guide

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-28 SUPPLEMENTAL RESTRAINT SYSTEM

– Driver air bag assembly
– Passenger air bag assembly
– Steering wheel
– SRS coil assembly
– Steering column
– Knee bolster and instrument panel mounting
attachments
– Driver seat and belt
– Passenger seat and belt
– SRS control unit
SRS control unit always should be checked according
to “SRS Control Unit Replacement Guidelines.”
CAUTION: Refer to “SRS control unit Replacement
Guidelines” below for important information on
SRS control unit replacement in both deployment
and non–deployment crashes.
Inspect SRS coil assembly wiring and steering wheel
for any sign of scorching, melting, or damage due to
excessive heat. If coil assembly wire or steering wheel
is damaged, replace them. The steering column and
wheel must be dimensionally checked to determine if
they are damaged. Refer to steering wheel of in this
manual.
Never use SRS parts from another vehicle. This does
not include remanufactured parts purchased from an
authorized Isuzu Retailer; they may be used for SRS
repairs.
Do not attempt to repair the SRS control unit, the SRS
harness, the SRS coil assembly, the air bag assembly,
the steering wheel, or the steering column. Service of
these items is replacement only. Verify replacement
part numbers.
CAUTION: Proper operation of the SRS control
unit and supplemental restraint system (SRS)
requires that any repairs to the vehicle structure
return it to its original production configuration.

SRS Connectors
CAUTION: The special yellow color connectors are
used for supplemental restraint system-air bag
circuit. When removing the cable harness, do not
pull the cables otherwise, cable disconnection
may occur. When connect the SRS connector,
insert the connector completely. Imperfect locking
may cause malfunction of SRS circuit.


Removal
To remove the connector, hold the cover insulator (1)
and pull it. The cover insulator slides and lock will be
released. Do not hold the socket insulator (2).
827RW028

9A-32 SUPPLEMENTAL RESTRAINT SYSTEM

Driver Air Bag Assembly
Service Precautions
WARNING: SAFETY PRECAUTIONS MUST BE
FOLLOWED WHEN HANDLING A DEPLOYED AI
R
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. NEVE
R
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 AI
R
BAG ASSEMBLY ON A BENCH OR OTHER
SURFACE, ALWAYS FACE BAG AND TRIM 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, inspec
t
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
1. Disable the SRS (Refer to “Disabling the SRS” in
this section).



2. Check the both side hole of the steering cover.
060R300025
3. Check the position of the pins in a hole. Push the
pin in the direction of an arrow.
060R300032

9A-34 SUPPLEMENTAL RESTRAINT SYSTEM

2. Connect the SRS air bag connector pin.

060R300042
3. Align the each snap stud of driver air bag to the
hole of steering wheel.
060R300030


060R300020
4. Push the SRS air bag area1 and area2. At that
time confirm the audible noise of each stud.
060R300036
5. Enable the SRS (Refer to “Enabling the SRS” in
this section).
CAUTION: Never use the air bag assembly from
another vehicle and difference model year air bag
assembly.
Use only new air bag assembly proper to the
TFR/S which is being repaired.

SUPPLEMENTAL RESTRAINT SYSTEM 9A-35

Steering Wheel
Service Precautions
WARNING: SAFETY PRECAUTIONS MUST BE
FOLLOWED WHEN HANDLING A DEPLOYED AI
R
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. NEVE
R
CARRY AIR BAG ASSEMBLY BY THE WIRES O
R
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 AI
R
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.
In the event deployment has occurred, inspect coil
assembly wire for any signs of scorching, melting o
r
any other damage due to excessive heat. If the coil
has been damaged, replace it.

Removal
1. Remove the SRS air bag assembly. (Refer to
“Driver Air Bag Assembly” in this section)

2. Remove steering wheel attachment nut.

060R300009
3. Apply a setting mark across the steering wheel
and shaft so parts can be reassembled in thei
r
original position.
060R300024
4. Move the tires to the straight ahead position before
removing the steering wheel. Install steering wheel
puller onto steering wheel and remove steering
wheel with 5-8521-0016-0.
5. Feed wiring through the wheel and remove wheel.
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.

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-37

SRS Coil Assembly
Service Precautions
WARNING: SAFETY PRECAUTIONS MUST BE
FOLLOWED WHEN HANDLING A DEPLOYED AI
R
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. NEVE
R
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 AI
R
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, inspec
t
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
1. Remove the SRS air bag assembly. (Refer to
“Driver Air Bag Assembly” in this seciton)


2. Remove the steering wheel attachment nut.

060R300009
3. Apply a setting mark across the steering wheel
and shaft so parts can be reassembled in thei
r
original position.
060R300024
4. Move the tires to the straight ahead position before
removing the steering wheel and remove wheel
with 5-8521-0016-0.
5. Feed wiring though the wheel and remove wheel.
6. Remove the steering lower cover and engine hood
opening lever.
7. Remove the driver knee bolster assembly.
8. Remove the steering column cover.
9. Remove air conditioning lower duct.
10.Disconnect the wiring harness connectors located
at the base of steering column.

9A-38 SUPPLEMENTAL RESTRAINT SYSTEM

CAUTION: Never apply force to the steering wheel
in the 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.
11. Remove the combination switch assembly with
SRS coil.
NOTE: 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.

Installation
1. Install the combination switch assembly with SRS
coil.
2. 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 the
cable in the SRS coil.
826RW014
Legend
(1) Neutral mark

3. Connect the wiring harness connectors located at
the base of steering column.
4. Install the air conditioning lower duct.
5. Install the 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
6. Install the driver knee bolster assembly.
7. Install the steering lower cover and engine hood
opening lever.
8. Install the steering wheel and align the setting
marks.
060R300024

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).

9A-40 SUPPLEMENTAL RESTRAINT SYSTEM

Steering Column
Service Precautions
WARNING: SAFETY PRECAUTIONS MUST BE
FOLLOWED WHEN HANDLING A DEPLOYED AI
R
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. NEVE
R
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 AI
R
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.
In the event deployment has occurred, inspect coil
assembly wire for any signs of scorching, melting o
r
any other damage due to excessive heat. If the coil
has been damaged, replace it.

Removal
1. Remove the SRS air bag assembly. (Refer to
“Driver Air Bag Assembly” in this section)


2. Remove the steering wheel attachment nut.

060R300009
3. Apply a setting mark across the steering wheel
and shaft so parts can be reassembled in thei
r
original position.
060R300024
4. Move the tires to the straight ahead position before
removing the steering wheel and removing wheel
with 5-8521-0016-0.
5. Feed wiring though the wheel and remove wheel.
6. Remove the steering lower cover and engine hood
opening lever.