sensor ISUZU TF SERIES 2004 Workshop Manual

9A-14 SUPPLEMENTAL RESTRAINT SYSTEM

Repairs And Inspections Required
After An Accident
If any SRS components are damaged, they must be
replaced. If SRS component mounting points are
damaged, they must be replaced.
 Never use SRS parts from another vehicle. This
does not include remanufactured parts purchased
from an authorized dealer; they may be used fo
r
SRS repairs.
 Do not attempt to service the SRS control unit, the
SRS coil assembly, or the air bag assembly.
Service of these items is by replacement only.

Verify the part number of replacement air bag
assembly.

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.
CAUTION: Proper operation of the sensors and
supplemental restraint system (SRS) requires that
any repairs to the vehicle structure return it to the
original production configuration. Deployment
requires, at a minimum, replacement of the SRS
control unit, air bag assembly and dimensional
inspection of the steering column. Any visible
damage to the SRS control unit mounting bracket
(s) requires replacement, and the steering column
must be dimensionally inspected, whethe
r
deployment occurred or not.
Accident With Deployment – Component
Replacement And Inspections
Certain SRS components must be replaced or
inspected for damage after a frontal crash involving air
bag deployment. Those components are:
 Air bag assembly
 SRS control unit

CAUTION: Refer to “SRS control unit
Replacement Guidelines” below for important
information on SRS control unit replacement in
both deployment and non deployment crashes.
 SRS coil assembly — Inspect wiring and connecto
r
for any signs of scorching, melting, or damage due
to excessive heat. Replace if damaged. Refer to
section “SRS Coil Assembly” in this manual.
Accident With or Without Deployment –
Component Inspection
Certain SRS system components and rotation parts
must be inspected after any crash, whether the air bag
deployed or not. Those components are:
 Steering column —Refer to Inspection Required
“After an Accident” in this manual.
 Knee bolsters and mounting points —Inspect fo
r
any distortion, bending, cracking, or other damage.
 I/P steering column reinforcement plate —Inspect
for any distortion, bending, cracking, or othe
r
damage.
 I/P braces —Inspect for any distortion, bending,
cracking, or other damage.
 Seat belts and mounting points — Refer to “Seat
Belts” in Section “Seat Belt” of this workshop
manual.

SRS Control Unit Replacement Guidelines
SRS control unit replacement policy requires
replacement of SRS control unit, after crash involving
air bag deployment when “SRS Warning Lamp” turn
“ON”, “SRS Diagnosis” should be done according to
Section “Restraint Control System.”

Wiring Damage
If any SRS wire harness is damaged, it should be
replaced. Don't repair SRS harness. It is replace only.

SRS Connector (Plastic Body And
Terminal Metal Pin) Damage
If any connector or terminal in the SRS wire harness
(except pigtails) is damaged, it should be replaced.

SRS Wire Pigtail Damage
If the wiring pigtail (a wire or wires attached directly to
the device, not by a connector) is damaged, the entire
component (with pigtail) must be replaced. Examples
of “pigtail” components are the driver air bag
assembly, the passenger air bag assembly, and the
SRS coil assembly.

SUPPLEMENTAL RESTRAINT SYSTEM 9A-15

On–Vehicle Service
Service Precaution
WARNING: WHEN PERFORMING SERVICE ON OR
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 “LOCK” and remove key.
1. Remove SRS fuse “SRS”, from the side of the
driver side of instrument panel fuse block o
r
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 manual.
4. Disconnect yellow 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
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.
Turn ignition switch to “LOCK” and remove key.
1. Connect yellow connector passenger air bag
assembly.
2. Install glove box assembly. Refer to “Passenger ai
r
bag assembly replacement” in this manual.
3. Connect yellow connector at the base of steering
column.
4. Install “AIR BAG” fuse “SRS” to the side of the
driver side of instrument panel fuse block o
r
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
manual.

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 sensor pointing
toward the front of the vehicle. It is very 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 replacement.

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.

RESTRAINT CONTROL 9A1-37

DTC B0051 (Flash Code 51) Squib Circuit Activated (Crash Detected)


RTW49JLF000101

Circuit Description
The SRS control unit contains a sensor which converts
vehicle velocity changes to an electrical signal. The
electrical signal generated is processed by the SRS
control unit and then compared to a value stored in
memory. When the generated signal exceeds the
stored value, the SRS control unit will cause current to
flow through the air bag assembly deploying the ai
r
bags and causing DTC B0051 to set.

DTC Will Set When
The SRS control unit detects a frontal crash, up to 30
degrees off the centerline of the vehicle, of sufficient
force to warrant deployment of the air bags.

Action Taken
SRS control unit turns “ON” the “AIR BAG” warning
lamp records “Crash Data”, and sets a diagnostic
trouble code.

DTC Will Clear When
The SRS control unit is replaced.

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2.
If air bag assembly(s) has not deployed, DTC B0051
may have falsely set.
3.
If DTC B0051 has set with no signs of frontal impact,
the diagnostic trouble code has falsely set.

RESTRAINT CONTROL 9A1-39

DTC B0053 (Flash Code 53) Deployment Command Despite Present Trouble
Code


RTW49JLF000101

Circuit Description
The SRS control unit contains a sensor which converts
vehicle velocity changes to an electrical signal. The
electrical signal generated is processed by the SRS
control unit and then compared to a value stored in
memory. When the generated signal exceeds the
stored value, the SRS control unit will cause current to
flow through the air bag assembly deploying the ai
r
bags. DTC B0053 is set accompanying with DTC
B0051 when a deployment occurs while an air bag
assembly circuit fault is present that could possible
result in a no deployment situation in one or both air bag
assemblies.


DTC Will Set When
The SRS control unit detects a frontal crash, up to 30
degrees off the centerline of the vehicle, of sufficient
force to warrant deployment of the air bags and an
inflator circuit fault is present.

Action Taken
SRS control unit turns “ON” the “AIR BAG” warning
lamp records “Crash Data”, and sets a diagnostic
trouble code.

DTC Will Clear When
The SRS control unit is replaced.

RESTRAINT CONTROL 9A1-61

DTC B1000 (Flash Code 72) SDM Internal Fault (SDM=SRS control unit)


RTW49JLF000101
Circuit Description
DTC B1000 is an indication of a potential internal SRS
control unit malfunction and will set if any of the
following conditions are detected:
1) Microprocessor energy reverse time failure.
2) EEPROM read / write failure.
3) ROM check sum.
4) Calibration check sum fault.
5) Inflators reserve voltage low.
6) Inflators electronic sensor active signal not detected
during commanded deployment.
7) QSDD (High-side/Low-side) FET failure.
8) Frontal accelerometer failure.
9) Phase lock loop lost lock.
10) QSDD communication fault.
DTC Will Set When
Any of the above indicated malfunctions are detected by
the SRS control unit. The malfunctions described
above are tested mainly during “Continuous Monitoring”
and some ones run each ignition cycle.

Action Taken
SRS control unit turns “ON” the “AIR BAG” warning
lamp and sets a diagnostic trouble code.

DTC Will Clear When
SRS control unit is replaced.

REAR AXLE 4B-9

REAR AXLE
1.
Refer to Section 3E "WHEEL and TIRE" for road
wheel Disassembly procedure.
2.
Refer to Section 5 "BRAKE" for rear brake
removal procedure.


RTW34BLF000401
Legend


1. Brake Drum

2. Bolt and Nut

3. Axle Shaft Assembly with Brake

4.
Shim

5. Snap Ring

6. Axle Shaft

7. Sensor Rotor (with ABS)

Spacer (without ABS)

8.
Double Taper Roller Bearing

9. Oil Seal

10.
Bearing Holder

11. Rear Brake

12. Bolt and Nut

13. Differential Assembly

14. Rear Axle Case Assembly

15. Wheel Pin

16. Axle Case Oil Seal

17.
Front

4B-10 REAR AXLE

Disassembly

Raise vehicle to the working level.

Support the axle assembly with the proper jack
and chassis stands.

Remove wheel and tire.

Drain differential oil.

Remove propeller shaft. (Refer to the section
“Rear Propeller Shaft”.)

1.
Remove brake drum.
2. Remove ABS sensor. (Refer to the section “ABS”.)
3. Remove brake pipe from wheel cylinder.
420R300003

4B-12 REAR AXLE

Legend


1.
Offset Box Wrench

10.
Remove wheel cylinder.
11.
Remove bearing holder fixing nuts.
12.
Take out axle shaft assembly with back plate and
set it on a bench press as following illustration.
Put bolt head on thick steel plate.

When axle shaft is extracted, since axle case oil
seal is damaged, axle case oil seal.
13.
Remove snap ring. Use snap ring pliers to
remove. Snap ring is prohibition of reuse.
14.
Remove shim (If so equipped)
15.
Remove sensor rotor (or spacer), double tape
r
roller bearing, oil seal, bearing holder, and back
plate from axle shaft by means of a press.

Discard used oil seal, double taper roller
bearing, snap ring, ABS sensor rotor and
spacer.
A03R300002
Legend

1.
Bench Press Fitting

2. Steel Plate (25-30 mm thickness)
3. Axle Shaft

16. Remove differential assembly fixing bolts and
nuts and take out differential assembly.
17.
Remove wheel pin from axle shaft, using the
remover 5-8840-0079-0.
420L100009
18.
Remove axle case oil seal.

Discard used oil seal.

REAR AXLE 4B-15

5.
Axle Shaft Assembly
a. Insert new double taper roller bearing in the
bearing holder with oil seal.
b. Set special tool (support stand : 9-8522-1271-
0) on a bench press.
c. Put bearing holder with bearing and oil seal
and back plate on the support stand as
following illustration.
d. Insert bolts and axle shaft, aligning center of
holes.
e. Press fit axle shaft into double taper roller
bearing.





420R300010
Legend


1.
Axle shaft

2.
Oil Seal
3.
Bolt

4.
Back Plate

5.
Double Taper Roller Bearing

6.
Put new sensor rotor (or spacer) on the special
tool 9-8522-1271-0.
7.
Press fit axle shaft with the bearing into sensor
rotor and make axle shaft assembly.





420R300011
Legend


1.
Axle shaft

2.
Oil Seal
3.
Bolt

4.
Back Plate

5.
Sensor Rotor (or Spacer)

6.
Double Taper Roller Bearing