2007 ISUZU KB P190 Harness

9A1-54 RESTRAINT CONTROL SYSTEM

DTC B0042 (Flash Code 42) Driver 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” “Driver Pretensioner
Low” terminal “7” is grounded through a current sink
and the driver current source connected to “Drive
r
Pretensioner High” terminal “8” allows a known amount
of current to flow. By monitoring the voltage difference
between “Driver Pretensioner High” and “Drive
r
Pretensioner Low”, the SRS control unit calculates the
combined resistance of the driver pretensione
r
assembly, SRS coil assembly, harness wiring circuits
“Driver Pretensioner High” and “Driver Pretensione
r
Low” and connector terminal contact.


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-55

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

DTC Will Set When
The combined resistance of the driver pretensioner
assembly, harness wiring circuits “Driver Pretensioner
High” and “Driver Pretensioner Low”, and connector
terminal contact is above a specified value. This test
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 DTC B0042.

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 driver seat.
4. This test checks for proper contact and/or corrosion
of the connector terminals at the base of the drive
r
seat.
5. This test isolate the malfunction to one side of the
SRS coil assembly yellow connector located at the
base of the driver seat.
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 driver pretensioner assembly.

Diagnostic Aids

An intermittent condition is likely to be caused by a poor
connection at the drive pretensioner harness connecto
r
terminals “1” and “2”, SRS control unit terminals “8” and
“7”, or a poor wire to terminal connection in circuit
“Driver Pretensioner High” or “Driver Pretensioner Low”
The 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 reappear until the next ignition cycle.

DTC B0042 (Flash Code 42) Driver Pretensioner 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 pretensioner squib 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. Disconnect SRS coil assembly yellow connector located at
base of the driver seat.
Is the connector connected properly? Go to Step 4 Seat pretensioner
assembly
connector properly.
Go to Step 8

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ISUZU KB P190 2007

9A1-56 RESTRAINT CONTROL SYSTEM

Step Action Yes No
4
1. Disconnect and inspect the pretensioner assembly yellow
connector located base of the driver seat.
2. If ok, reconnect the pretensioner yellow connector.
3. Ignition switch is at “ON”.
Is DTC B0042 current? Go to Step 5 Go to Step 8
5

1. Ignition switch is at “LOCK”.
2. Disconnect diver pretensioner assembly, yellow connector
located at the base of driver seat.
3. Connect SRS driver / passenger load tool 5-8840-2421-0 and
appropriate adapter to driver pretensioner assembly harness
connectors.
4. Ignition switch is at “ON”.
Is DTC B0042 current? Go to Step 6 Go to Step 7
6

1. Ignition switch is at “LOCK“.
2. There has been a increase in the total circuit resistance of the
driver deployment loop.
3. Use the high resolution ohmmeter mode of the DVM while
checking circuits “Driver Pretensioner High” and “Driver
Pretensioner Low”, and SRS control unit connector terminal
“8” and “7” to locate the root cause.
W as a fault found? Replace
pretensioner harness.
Go to Step 8 Go to Chart A
7

1. Ignition switch is at “LOCK”.
2. Disconnect pretensioner load tool from pretensioner
assembly harness connector.
3. Connect pretensioner load tool 5-8840-2421-0 and appropriate adapter to driver pretensioner assembly harness
connector.
4. Reconnect pretensioner harness connector as the base of the
driver seat.
5. Ignition switch is at “ON”.
Is DTC B0065 current? Ignition switch is at
“LOCK”.
Replace
pretensioner assembly.
Go to Step 8 Ignition switch is at
“LOCK”.
Replace driver pretensioner assembly.
Go to Step 8
8
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

9A1-58 RESTRAINT CONTROL SYSTEM

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

DTC Chart Test Description
Number(s) below refer to circled 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 driver pretensioner assembly yellow connector at the
base of the driver seat.
4. This test determines whether the malfunction is in “Driver Pretensioner High” circuit.
5. This test determines whether the malfunction is in “Driver Pretensioner Low” circuit.

Diagnostic Aids
An intermittent condition is likely to be caused by a short
to ground in the driver pretensioner assembly circuit.
Inspect circuits “Driver Pretensioner High” and “Drive
r
Pretensioner Low” carefully for cutting or chafing. If the
wiring pigtail of the driver pretensioner assembly is
damaged, the component must be replaced. A careful
inspection of “Driver Pretensioner High” and “Drive
r
Pretensioner Low”, including the driver pretensione
r
assembly pigtail is essential to ensure that the
replacement SRS control unit will not be damaged.


DTC B0045 (Flash Code 45) Driver Pretensioner 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 pretensioner air bag squib circuit for short to ground.
W as a problem found? Go to Step 3

3
1. Ignition switch is at “LOCK”.
2. Disconnect driver pretensioner assembly yellow connector at
the base of the driver seat.
3. Leave driver air bag assembly connected.
4. Connect SRS driver / driver load tool 5-8840-2421-0 and
appropriate adapter to driver air bag assembly harness
connector.
5. Ignition switch is at “ON”.
Is DTC B0045 current? Go to Step 4 Ignition switch is at
“LOCK”.
Replace driver pretensioner assembly .
Go to Step 6
4 1. Ignition switch is at “LOCK”.
2. Disconnect the SRS driver /driver load tool.
3. Measure the resistance on the SRS control unit harness connector as follow.
z From terminals "8" to "3" and "15" (ground) (with the
passenger air bag)
z From terminals "8" to "3", "12" and "15" (ground) (without
the passenger air bag)
Does 5-8840-0366-0 display “OL” (Infinite)? Go to Step 5 Replace SRS
Harness.
Go to Step 6

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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-59

Step Action Yes No
5 Measure the resistance on the SRS control unit harness
connector as follow.
z From terminals "7" to "3" and "15" (ground) (with the
passenger air bag)
z From terminals "7" to "3", "12" and "15" (ground) (without
the passenger air bag)
Does 5-8840-0366-0 display “OL” (Infinite)? Go to Chart A Replace SRS
Harness.
Go to Step 6
6 1. Reconnect all the components and ensure all components
are properly mounted.
2. Clear diagnostic trouble codes.
Is this step finished? Go to the “SRS
Diagnostic system Check” ―



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TO MODEL INDEX
ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-61

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

DTC Chart Test Description
Number(s) below refer to circled 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 driver pretensioner assembly yellow connector at the
base of the driver seat.
4. This test determines whether the malfunction is in “Driver Pretensioner High” circuit.
5. This test determines whether the malfunction is in “Driver Pretensioner Low” circuit.

Diagnostic Aids
An intermittent condition is likely to be caused by a short
to +B in the driver pretensioner assembly circuit.
Inspect circuits “Driver Pretensioner High” and “Drive
r
Pretensioner Low” carefully for cutting or chafing. If the
wiring pigtail of the driver pretensioner assembly is
damaged, the component must be replaced. A careful
inspection of “Driver Pretensioner High” and “Drive
r
Pretensioner Low”, including the driver pretensione
r
assembly pgtail is essential to ensure that the
replacement SRS control unit will not be damaged.


DTC B0046 (Flash Code 46) Driver Pretensioner 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 a short to voltage.
W as a problem found? Go to Step 3

3
1. Ignition switch is at “LOCK”.
2. Disconnect driver pretensioner assembly yellow connector at
the base of the driver seat.
3. Leave driver air bag assembly connected.
4. Connect SRS driver / passenger load tool 5-8840-2421-0 and
appropriate adapter to driver air bag assembly harness
connector.
5. Ignition switch is at “ON”.
Is DTC B0046 current? Go to Step 4 Ignition switch is at
“LOCK.”
Replace driver pretensioner assembly .
Go to Step 6
4 Measure the resistance on the SRS control unit harness
connector from terminal “8” to terminal “1” (ignition).
Does 5-8840-0366-0 display “OL” (Infinite)? Go to Step 5 Replace SRS
Harness.
Go to Step 6
5 Measure the resistance on the SRS control unit harness connector from terminal “7” to terminal “1” (ignition).
Does 5-8840-0366-0 display “OL” (Infinite)? Go to Chart A Replace SRS
Harness.
Go to Step 6
6 1. Reconnect all the components and ensure all components
are properly mounted.
2. Clear diagnostic trouble codes.
Is this step finished? Go to the “SRS
Diagnostic system Check” ―



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TO MODEL INDEX
ISUZU KB P190 2007

9A1-66 RESTRAINT CONTROL SYSTEM

DTC B0055 (Flash Code 55) Vehicle Variant Missing



RTW 79ALF000301



Circuit Description
DTC B0055 will be set, if either the SRS control unit or
the SRS control unit harness is not genuine parts.
The correct conditions of terminals on the SRS control
unit and the SRS harness are as follows.

Terminal No. 12 15 23 26
W ithout
Pretensioner - - used -
W ith Pretensioner - used - -
W ith Pretensioner
and W ithout
Passenger Air Bg used used - -


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-67


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. Ignition switch is at “LOCK”.
2. Disconnect the SRS control unit.
3. Inspect the SRS control unit harness for the following condition.
z W ithout the pretensioner:
- The wiring harness is not connected on terminal "23"
- The wiring harness is connected on terminals "12", "15" and "26"
z W ith the pretensioner:
- The wiring harness is not connected on terminal "15"
- The wiring harness is connected on terminals "12", "23" and "26"
z W ithout the pretensioner and without the passenger air
bag:
- The wiring harness is not connected on terminals "12" and "15"
- The wiring harness is connected on terminals "23" and "26"
W as a problem found? Replace the SRS
control unit harness.
Go to Step 3 Replace the SRS
control unit.
Go to Step 3
3 1. Reconnect all components and ensure all components are
properly mounted.
2. Clear the diagnostic trouble codes.
Is this step finished? Go to the “SRS
Diagnostic System Check” ―



DTC Will Set When
z W ithout the pretensioner:
Terminals "12", "15" and "26" are shorted to
ground.
Terminal "23" is open (harness is not connected).
z W ith the pretensioner:
Terminals "12", "23" and "26" are shorted to
ground.
Terminal "15" is open (harness is not connected).
z W ith the pretensioner and without the passenge
r
air bag:
Terminals "23" and "26" are shorted to ground.
Terminals "12" and "15" are open (harness is not
connected).
It is DTC set, if non genuine SRS control unit is installed
with the SRS harness genuine part, or incase o
f
terminal "12", "15", "23" and "26" are abnormal
condition with the SRS control unit genuine part.

Action Taken
The SRS control unit turns “ON" the “SRS" warning
lamp and sets a DTC B0055.
But if there is abnormal condition with the SRS control
unit and/or SRS harness, the DTC is not set.

DTC Will Clear When
DTC B0055 can be cleared only by using the scan tool.

Diagnostic Aids
Ensure that terminal "12" is shorted to ground on the
SRS harness. Terminal "15", "23" and "26" are open
circuit.
DTC B0055 (Flash Code 55) Vehicle Variant Missing

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ISUZU KB P190 2007