2007 ISUZU KB P190 Wiring

9A1-28 RESTRAINT CONTROL SYSTEM

DTC B0021 (Flash Code 21) Driver Air Bag Squib Circuit High Resistance




RTW 79ALF000301

Circuit Description
W hen the ignition switch is turned “ON”, the SRS
control unit will perform tests to diagnose critical
malfunctions within itself. Upon passing these tests,
“Ignition 1”, and deployment loop voltages, are
measured to ensure they are within their respective
normal voltage ranges.

The SRS control unit then proceeds with the
“Resistance Measurement Test”. “Driver Bag Low”
terminal “13” is grounded through a current sink and the
driver current source connected to “Driver Bag High”
terminal “14” allows a known amount of current to flow.
By monitoring the voltage difference between “Drive
r
Bag High” and “Driver Bag Low”, the SRS control unit
calculates the combined resistance of the driver air bag
assembly, SRS coil assembly, harness wiring circuits
“Driver Bag High” and “Driver Bag Low” and connecto
r
terminal contact.

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TO MODEL INDEX
ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-29

DTC Will Set When
The combined resistance of the driver air bag
assembly, the SRS Coil assembly, the harness wiring
circuits “Driver Bag High” and “Driver Bag Low”, and
connector terminal contact is above a specified value.
This test runs once for each ignition cycle during the
“Resistance Measurement Test” when:
1. No “higher priority faults” are detected during “Turn–
ON”.
2. “Ignition 1” voltage is in the specified value.

Action Taken
The SRS control unit turns “ON” the “SRS” warning
lamp and sets DTC B0021.

DTC Will Clear When
Resistance value returns to specified resistance value.

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the malfunction is in
the SRS control unit.
3. This test verifies proper connection of the yello
w
connector at the base of the steering column.
4. This test checks for proper contact and/or corrosion
of the connector terminals at the base of the steering
column.
5. This test isolates the malfunction to one side of the
SRS coil assembly yellow connector located at the
base of the steering column.
6. This test determines whether the malfunction is due
to high resistance in the wiring.
7. This test determines whether the malfunction is in
the SRS coil assembly or the driver air bag
assembly.

Diagnostic Aids
An intermittent condition is likely to be caused by a poor
connection at terminals “1” and “2” of the SRS coil
connector at the base of the steering column, terminal
“1” and “2” of the driver air bag assembly connector at
the top of the steering column, the SRS control unit
terminals “14” and “13” or a poor wire to terminal
connection in circuit “Driver Bag High” or “Driver Bag
Low” The test for this diagnostic trouble code is only run
while the “SRS” warning lamp is performing the bulb
check. W hen a scan tool “Clear Codes” command is
issued and the malfunction is still present, the DTC will
not reappear until the next ignition cycle.

DTC B0021 (Flash Code 21) Driver Air Bag Squib Circuit High Resistance

Step Action Yes No
1 Perform the “SRS Diagnostic System Check”.
W as the “SRS Diagnostic System Check” performed? Go to Step 2 Repeat the “SRS
Diagnostic System Check”
2
1. Check the driver air bag squib circuit for open.
2. If a the problem is found, repair as necessary.
W as a problem found? Verify repair Go to Step 3
3

1. Ignition switch to “LOCK”.
2. Disconnect the SRS coil assembly yellow connector located
at the base of the steering column and check it is seated
properly.
Is the connector connected properly? Go to Step 4 Seat SRS coil
assembly
connector properly. Go to Step 8

BACK TO CHAPTER INDEX TO MODEL INDEX
ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-31

DTC B0022 (Flash Code 22) Driver Air Bag Squib Circuit Low Resistance




RTW 79ALF000301

Circuit Description
W hen the ignition switch is turned “ON”, the SRS
control unit will perform tests to diagnose critical
malfunctions within itself. Upon passing these tests
“Ignition 1”, and deployment loop voltages, are
measured to ensure they are within their respective
normal voltage ranges.

The SRS control unit then proceeds with the
“Resistance Measurement Test”. “Driver Bag Low”
terminal “13” is grounded through a current sink and the
driver current source connected to “Driver Bag High”
terminal “14” allows a known amount of current to flow.
By monitoring the voltage difference between “Drive
r
Bag High” and “Driver Bag Low” the SRS control unit
calculates the combined resistance of the driver air bag
assembly, SRS coil assembly, harness wiring circuits
“Driver Bag High” and “Driver Bag Low” and connecto
r
terminal contact.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

9A1-32 RESTRAINT CONTROL SYSTEM

DTC Will Set When
The combined resistance of the driver air bag
assembly, SRS Coil assembly, harness wiring circuits
“Driver Bag High” and “Driver Bag Low”, and connecto
r
terminal contact is above a specified value. This test is
run once for each ignition cycle during the “Resistance
Measurement Test” when:
1. No “higher priority faults” are detected during “Turn–
ON”
2. “Ignition 1” voltage is in the specified value.

Action Taken
The SRS control unit turns “ON” the “SRS” warning
lamp and sets DTC B0022.

DTC Will Clear When
Resistance value returns to specified resistance value.

DTC Chart Test Description
Number(s) below refer to circled number(s) on the
diagnostic chart:
2. This test determines whether the malfunction is in
the SRS control unit.
3. This test verifies proper connection of the yello
w
connector at the base of the steering column.
4. This test checks for proper operation of the shorting
clip in the yellow connector.
5. This test isolates the malfunction to one side of the
SRS coil assembly yellow connector located at the
base of the steering column.
6. This test determines whether the malfunction is due
to shortening in the wiring.
7. This test determines whether the malfunction is in
the SRS coil assembly or the driver air bag
assembly.

Diagnostic Aids
An intermittent condition is likely to be caused by a short
between circuit “Driver Bag High” or “Driver Bag Low”
and a malfunctioning shorting clip on the driver air bag
assembly or the SRS coil assembly which would require
replacement of the component. The test for this
diagnostic trouble code is only run while the “SRS”
warning lamp is performing the bulb check. W hen the
scan tool “Clear Codes” command is issued and the
malfunction is still present, the DTC will not reappea
r
until the next ignition cycle.


DTC B0022 (Flash Code 22) Driver Air Bag Squib Circuit Low Resistance

Step Action Yes No
1 Perform the “SRS Diagnostic System Check.”
W as the “SRS Diagnostic System Check” performed? Go to Step 2 Go to the “SRS
Diagnostic System Check”
2
1. Check the driver air bag squib circuit for short to voltage or
short to ground.
2. If a problem is found, repair as necessary.
W as a problem found? Verify repair Go to Step 3
3

1. Ignition switch to “LOCK”.
2. Make sure the SRS coil assembly yellow connector located at
the base of steering column is seated properly.
Is the connector connected properly? Go to Step 4 Seat driver air bag
assembly
connector properly. Go to Step 8
4
1. Disconnect and inspect the SRS coil assembly yellow
connector located at the base of the steering column.
2. If ok, reconnect the SRS coil assembly yellow connector.
3. Ignition switch is “ON”.
Is DTC B0022 current? Go to Step 5 Go to Step 8

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TO MODEL INDEX
ISUZU KB P190 2007

9A1-40 RESTRAINT CONTROL SYSTEM

DTC B0029 (Flash Code 29) Passenger Pretensioner Squib Circuit High
Resistance



RTW 79ALF000301

Circuit Description
W hen the ignition switch is turned “ON”, the SRS
control unit will perform tests to diagnose critical
malfunctions within itself. Upon passing these tests
“Ignition 1”, and deployment loop voltages are
measured to ensure they are within their respective
normal voltage ranges. The SRS control unit then
proceeds with the “Resistance Measurement Test”.
“Passenger Pretensioner Low” terminal “10” is
grounded through a resister and the passenger current
source connected to “Passenger Pretensioner High”
terminal “11” allows a known amount of current to flow.

By monitoring the voltage difference between
“Passenger Pretensioner High” and “Passenger
Pretensioner Low” the SRS control unit calculates the
combined resistance of the passenger pretensione
r
assembly, harness wiring circuits “Passenger
Pretensioner High” and “Passenger Pretensioner Low”
connector terminal contact.


BACK TO CHAPTER INDEX TO MODEL INDEX
ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-41

DTC Will Set When
The combined resistance of the passenger air
pretensioner assembly, harness wiring circuits
“Passenger Pretensioner High” and “Passenge
r
Pretensioner Low”, and connector terminal contact is
above a specified value. This test is run once each
ignition cycle during the “Resistance Measurement
Test” when:
1. No “higher priority faults” are detected during “Turn–
ON”,
2. “Ignition 1” voltage is in the specified value.

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

DTC Will Clear When
The ignition switch is at “LOCK”.

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the malfunction is in
the SRS control unit.
3. This test verifies proper connection of the yello
w
connector.
4. This test checks for proper contact and/or corrosion
of the yellow connector terminals.
5. The test checks for a malfunctioning passenge
r
pretensioner assembly.
6. This test determines whether the malfunction is due
to high resistance in the wiring.

Diagnostic Aids

An intermittent condition is likely to be caused by a poor
connection at the passenger pretensioner assembly
harness connector terminals “1” and “2”, SRS control
unit terminal “11” and “10”, or a poor wire to terminal
connection in circuits “Passenger Pretensioner High”
and “Passenger Pretensioner Low”. This test for this
diagnostic trouble code is only run while the “AIR BAG”
warning lamp is performing the bulb check. W hen a
scan tool “Clear Codes” command is issued and the
malfunction is still present, the DTC will not reappea
r
until the next ignition cycle.



BACK TO CHAPTER INDEX TO MODEL INDEX
ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-43

DTC B0031 (Flash Code 31) Passenger Pretensioner Squib Circuit Low
Resistance



RTW 79ALF000301

Circuit Description
W hen the ignition switch is turned “ON”, the SRS
control unit will perform tests to diagnose critical
malfunctions within itself. Upon passing these tests
“Ignition 1”, and deployment loop voltages are
measured to ensure they are within their respective
normal voltage ranges. The SRS control unit then
proceeds with the “Resistance Measurement Test”.
“Passenger Pretensioner Low” terminal “10” is
grounded through a resistor and the passenger current
source connected to “Passenger Pretensioner High”
terminal “11” allows a known amount of current to flow.

By monitoring the voltage difference between
“Passenger Pretensioner High” and “Passenger
Pretensioner Low”, the SRS control unit calculates the
combined resistance of the passenger air bag
assembly, harness wiring circuits “Passenge
r
Pretensioner High” and “Passenger Pretensioner Low”
connector terminal contact.



BACK TO CHAPTER INDEX TO MODEL INDEX
ISUZU KB P190 2007

9A1-44 RESTRAINT CONTROL SYSTEM

DTC Will Set When
The combined resistance of the passenger pretensioner
assembly, harness wiring circuits “Passsenger
Pretensioner High” and “Passenger Pretensioner Low”,
and connector terminal contact is above a specified
value. This test is run once each ignition cycle during
the “Resistance Measurement Test” when:
1. No “higher priority faults” are detected during “Turn–
ON”,
2. “Ignition 1” voltage is in the specified value.

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

DTC Will Clear When
The ignition switch is turned “LOCK”.

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the malfunction is in
the SRS control unit.
3. This test verifies connection of the yellow connector.
4. This test cheeks for proper operation of the shorting
clip in the yellow connector.
5. The test checks for a malfunction passenge
r
pretensioner assembly.
6. This test determines whether the malfunctioning is
due to shortening in the wiring.

Diagnostic Aids

An intermittent condition is likely to be caused by a short
between circuits “Passenger Pretensioner High” and
“Passenger Pretensioner Low” or a malfunctioning
shorting clip on the passenger pretensioner assembl
y
which would require replacement of the pretensione
r
assembly. The test for this diagnostic trouble code is
only run while “AIR BAG” warning lamp is performing
the bulb check. W hen a scan tool “Clear Codes”
command is issued and the malfunction is still present,
the DTC will not reappear until the next ignition cycle.


BACK TO CHAPTER INDEX TO MODEL INDEX
ISUZU KB P190 2007