2007 ISUZU KB P190 FLASH CODE

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.

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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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ISUZU KB P190 2007

9A1-34 RESTRAINT CONTROL SYSTEM

DTC B0025 (Flash Code 25) Driver Air Bag Squib Circuit Short to GND




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 monitors the voltage at “Drive
r
Bag Low” terminal “13” and “Passenger Bag Low”
terminal “16” to detect shorts to ground/+B in the air bag
assembly circuits.

DTC Will Set When
“Ignition 1" is within the normal operating voltage range.
The voltage at “Driver Bag Low" is below a specified
value DTC B0025 will set.

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

DTC Will Clear When
The “Driver Bag Low" voltage comes to specified
voltage.


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-35

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the SRS control unit is malfunctioning.
3. This test isolates the malfunction to one side of the SRS coil assembly yellow 2–pin connector at the
base of the steering column.
4. This test determines whether the malfunction is in the “Driver Bag High” circuit.
5. This test determines whether the malfunction is in the “Driver Bag Low” circuit.
6. 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
to ground/+B in the driver air bag assembly circuit.
Inspect circuits “Driver Bag High” and “Driver Bag Low”
carefully for cutting or chafing.


DTC B0025 (Flash Code 25) Driver Air Bag Squib Circuit Short to GND

Step Action Yes No
1 W as the “SRS Diagnostic System Check” performed?
Go to Step 2 Go to the “SRS
Diagnostic System Check”
2 1. W hen measurements are requested in this chart use a 5-
8840-0366-0 DMM with a correct terminal adapter from 5-
8840-2835-0.
2. Ignition switch is at “LOCK”.
3. Ignition switch is “ON”.
4. Check the driver air bag squib circuit for short to voltage or short to ground and open.
W as a problem found? Go to Step 3

3 1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil assembly yellow connector located at base of the steering column. Leave the passenger air bag
assembly connected.
3. Connect the SRS driver /passenger load tool 5-8840-2421-0 and appropriate adapter to the SRS coil assembly harness
connector.
4. Ignition switch is “ON”.
Is DTC B0025 current? Go to Step 4 Go to Step 6
4
1. Ignition switch is at “LOCK”.
2. Disconnect the SRS control unit.
3. Disconnect the SRS driver /passenger load tool.
4. Measure the resistance on the SRS control unit harness connector as follow.
z From terminals "14" to "3" and "23" (ground) (without the
pretensioner)
z From terminals "14" to "3" and "15" (ground) (with the
pretensioner and the passenger air bag)
z From terminals "14" to "3", "12" and "15" (ground) (with
the pretensioner and without the passenger air bag)
Does 5-8840-0366-0 display “OL” (infinite)? Go to Step 5 Replace SRS
harness.
Go to Step 7

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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-37

DTC B0026 (Flash Code 26) Driver Air Bag Squib Circuit Short to Battery
Voltage



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 monitors the voltage at “Drive
r
Bag Low” terminal “13” and “Passenger Bag Low”
terminal “16” to detect shorts to ground/+B in the air bag
assembly circuits.

DTC Will Set When
“Ignition 1" is in the normal operating voltage range.
The voltage at “Driver Bag Low" is above a specified
value,
DTC B0026 will set.

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

DTC Will Clear When
The SRS control unit is replaced and the “Driver Bag
Low" voltage comes to specified voltage.

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ISUZU KB P190 2007

9A1-38 RESTRAINT CONTROL SYSTEM

DTC Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the SRS control unit is malfunctioning.
3. This test isolates the malfunction to one side of the SRS coil assembly yellow 2–pin connector at the
base of the steering column.
4. This test determines whether the malfunction is in the “Driver Bag High” circuit.
5. This test determines whether the malfunction is in the “Driver Bag Low” circuit.
6. 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
to ground/+B in the driver air bag assembly circuit.
Inspect circuits “Driver Bag High” and “Driver Bag Low”
carefully for cutting or chafing.


DTC B0026 (Flash Code 26) Driver Air Bag Squib Circuit Short to Battery Voltage

Step Action Yes No
1 W as the “SRS Diagnostic System Check” performed? Go to Step 2 Go to the “SRS
Diagnostic System Check”
2 1. W hen measurements are requested in this chart use a 5-
8840-0366-0 DMM with a correct terminal adapter from 5-
8840-2835-0.
2. Ignition switch is at “LOCK”.
3. Ignition switch is “ON”.
4. Check the driver air bag squib circuit for short to voltage or short to ground and open.
W as a problem found? Go to Step 3

3 1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil assembly yellow connector located at base of the steering column. Leave the passenger air bag
assembly connected.
3. Connect the SRS driver /passenger load tool 5-8840-2421-0 and appropriate adapter to the SRS coil assembly harness
connector.
4. Ignition switch is “ON”.
Is DTC B0026 current? Go to Step 4 Go to Step 6
4
Measure resistance on SRS control unit harness connector from
terminal “14” to terminal “1” (ignition).
Does 5-8840-0366-0 display “OL” (infinite)? Go to Step 5
Replace SRS
harness.
Go to Step 7
5 Measure the resistance on the SRS control unit harness
connector from terminal “13” to terminal “1” (ignition).
Does 5-8840-0366-0 display “OL” (infinite)? Go to Chart A Replace SRS
harness.
Go to Step 7

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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

9A1-42 RESTRAINT CONTROL SYSTEM

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

Step Action Yes No
1 W as the “SRS Diagnostic System Check” Performed?
Go to Step 2 Go to The “SRS
Diagnostic System Check”
2
1. Check the passenger pretensioner circuit for open.
2. If the problem found, repair as necessary.
W as a problem found? Verify repair Go to Step 3
3

1. Ignition switch is at “LOCK”.
2. Make sure the passenger air bag assembly yellow connector
located at the base of the passenger seat.
Is the yellow connector connected properly? Go to Step 4 Seat passenger
pretensioner
assembly yellow connector properly.
Go to Step 7
4
1. Disconnect and inspect the passenger pretensioner assembly
yellow connector located at the base of the passenger seat.
2. If ok, reconnect the passenger pretensioner assembly
connector.
3. Ignition switch “ON”.
Is DTC B0029 current? Go to Step 5 Go to Step 7
5

1. Ignition switch is at “LOCK”.
2. Disconnect passenger pretensioner assembly, yellow
connector located at the base of the passenger seat.
3. Connect 5-8840-2421-0 SRS driver / passenger load tool and
appropriate adapters to passenger pretensioner assembly
harness connectors.
4. Ignition switch “ON”.
Is DTC B0029 Current? Go to Step 6 Ignition switch is at
“LOCK.”
Replace the passenger
pretensioner assembly.
Go to Step 7
6
1. Ignition switch is at “LOCK”.
2. There has been an increase in the total circuit resistance of
the passenger loop.
3. Use the high resolution ohmmeter mode of the DVM while
checking circuits “Pasenger Pretensioner High” and
“Passenger Pretensioner Low”, and SRS control unit
connector terminal “11” and “10” to locate the root cause.
W as a fault found? Replace SRS
harness or repair chassis harness. Go to Step 7 Go to Chart A
7

1. Reconnect all components ensure all component are properly
mounted.
2. Clear diagnostic trouble codes.
W as This step finished? Repeat the “SRS
Diagnostic System Check” ―



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ISUZU KB P190 2007