ignition ISUZU KB P190 2007 Workshop Repair Manual

9A1-12 RESTRAINT CONTROL SYSTEM

Chart B “SRS” Warning Lamp Comes “ON” Steady




RTW 79ALF000301

Circuit Description
W hen the ignition switch is first turned “ON”, “Ignition 1”
voltage is applied from the “METER” fuse to the “SRS”,
warning lamp which is connected to “SRS W arning
Lamp”, terminal “4”. The “SRS” fuses apply system
voltage to the “Ignition 1” inputs, terminals “1”. The
SRS control unit responds by flashing the “SRS”
warning lamp 7 times. If “Ignition 1” is less than 9 volts,
the “SRS” warning lamp will come “ON” solid with no
DTCs set.

Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test checks for an open in the “Ignition 1” circuit to the SRS control unit.
3. This test checks for the voltage of “Ignition 1”.
4. This test determines whether the malfunction is a short to ground in the SRS warning lamp circuit.



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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-13

Chart B “SRS” warning lamp comes “ON” Steady

Step Action Yes No
1
1. W hen measurements are requested in this chart use a 5-
8840-0366-0DMM with correct terminal adapter from 5-8840-
0385-0.
2. Ignition switch is at “LOCK”.
3. Connect the scan tool to the data link connector, following
directions as given in the scan tool instruction MANUAL.
4. Ignition switch is “ON”.
5. Request the SRS diagnostic trouble code display.
Does the scan tool indicate “No Data Received”? Go to Step 2 Go to Step 3
2

1. Ignition switch is at “LOCK”.
2. Inspect the SRS control unit harness connector connection to
the SRS control unit.
Is it securely connected to the SRS control unit? Ignition switch
“LOCK”.
Replace SRS control unit.
Go to Step 5 Connect SRS
control unit
securely to de–
activate shorting
clip in SRS control unit harness connector.
Go to Step 5
3 Using scan tool, request the SRS data list.
Is “ignition” more than 9 volts? Go to Step 4 Ignition switch
“LOCK”.
Replace SRS control unit.
Go to Step 5
4
1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil and the passenger air bag assembly
yellow connector located at the base of the steering column
and behind the glove box assembly.
Disconnect the SRS control unit.
3. Disconnect the connector of the “SRS W arning Lamp” on the
instrument cluster.
4. Measure the resistance on the SRS control unit harness connector as follow.
z From terminals "3" and "23" to ground (ground) (without
the pretensioner)
z From terminals "3" and "15" to ground (ground) (with the
pretensioner and the passenger air bag)
z From terminals "3", "12" and "15" to ground (with the
pretensioner and without the passenger air bag)
Does 5-8840-0366-0DMM display “OL” (Infinite)? Go to Chart A Replace SRS
harness.
Go to Step 5
5 Reconnect all SRS components and ensure all components are
properly mounted.
Is this step finished? Repeat the “SRS
Diagnostic System Check” —


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ISUZU KB P190 2007

9A1-14 RESTRAINT CONTROL SYSTEM

Chart C “SRS” Warning Lamp Does Not Come “ON” Steady




RTW 79ALF000301

Circuit Description
W hen the ignition switch is first turned “ON”, “Ignition 1”
voltage is applied from the “METER” fuse to the “SRS”
warning lamp which is connected to the “SRS W arning
Lamp”, terminal “4”. The “SRS” fuse applies system
voltage to the “Ignition 1” inputs, terminals “35”. The
SRS control unit responds by flashing the “SRS”
warning lamp seven times. If “Ignition 1” is more than
16 volts, the “SRS” warning lamp will still be “OFF” solid
with no DTCs set.

Chart Test Description
Number(s) below refer to step number(s) on the
diagnostic chart:

1. This test decides whether power is available to the
SRS control unit warning lamp power feed circuit.
2. This test determines whether the voltage is present
in the warning lamp circuit.
3. This test determines if the malfunction is in the
instrument cluster.
4. This test checks for open in the warning lamp
circuitry.
5. This test isolates the SRS warning lamp circuit and
checks for a short in the SRS warning lamp circuit to
B+.
8. This test checks for a short from the SRS control
unit warning lamp power feed circuit to ground.
9. This test determines whether the short to ground is
due to a short in the wiring.


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-15

Chart C “SRS” Warning Lamp Does Not Come “ON” Steady

Step Action Yes No
1
1. W hen measurements are requested in this chart, use a 5-
8840-0366-0DMM with a correct terminal adapter from 5-
8840-0385-0.
2. Ignition switch is at “LOCK”.
3. Remove and inspect the “METER” fuse to the “SRS” warning lamp.
Is the fuse good? Go to Step 2 Go to Step 7
2

1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil and passenger air bag assembly
yellow connector which is located at the base of the steering
column and behind the glove box assembly.
3. Disconnect the SRS control unit.
4. Ignition switch is “ON”.
5. Measure the voltage on the SRS control unit harness connector from the terminal “4” to terminal “3” (ground).
Is system voltage present on terminal “4”? Go to Step 4 Go to Step 3
3

1. Ignition switch is at “LOCK”.
2. Remove instrument meter cluster.
3. Check for proper connection to instrument cluster at the SRS warning lamp circuit terminal.
4. If ok, then remove and inspect the “AIR BAG” bulb.
Is the bulb good? Go to Step 5 Replace bulb.
Go to Step 6
4
1. Ignition switch is at “LOCK”.
2. Disconnect instrument meter cluster harness connector.
3. Ignition switch is “ON”.
4. Measure the voltage on the SRS control unit harness
connector from terminal “4” to terminal “3” (ground).
Is the voltage 1 volt or less? Go to Chart A Replace SRS
harness.
Go to Step 6
5
1. Install the bulb.
2. Measure the resistance from the instrument meter cluster
harness connector SRS warning lamp circuit terminal to the
SRS control unit harness connector terminal “4”.
Is the resistance 5.0 ohms or less? Service instrument
meter cluster.
Install instrument meter cluster. Go to Step 6 Replace SRS
harness.
Go to Step 6
6 Reconnect all SRS components and ensure all components are
properly mounted.
Is this step finished? Repeat the “SRS
Diagnostic System Check” Go to Step 6
7
Perform chart C.
Is this step finished? Go to Step 8 Go to Step 1
8

1. Replace the “METER” fuse.
2. Ignition switch is “ON”. W ait 10 Seconds then ignition switch
is at “LOCK”.
3. Remove and inspect the “METER” fuse.
Is the fuse good? Install “METER”
fuse.
Go to Step 10 Go to Step 9

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ISUZU KB P190 2007

9A1-16 RESTRAINT CONTROL SYSTEM

Step Action Yes No
9
1. Disconnect the SRS coil and the passenger air bag assembly
yellow connectors located at the base of the steering column
and behind the glove box assembly.
2. Disconnect the SRS control unit.
3. Replace the “METER” fuse.
4. Ignition switch is “ON”-wait 10 seconds.
5. Ignition switch is at “LOCK”.
6. Remove and inspect the “METER” fuse.
Is the fuse good? Install “METER”
fuse.
Go to Chart A Replace SRS
harness.
Replace “METER” fuse.
Go to Step 10
10 Reconnect all the SRS components and ensure all the
components are properly mounted.
Is this step finished? Repeat the “SRS
Diagnostic System Check” —


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-17

DTC B0015 (Flash Code 15) Passenger Air Bag Squib Circuit High Resistance




RTW 79ALF000301
Circuit Description
W hen the ignition switch is turned to “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”.
The “Passenger Bag Low” terminal “16” is grounded
through a resister and the passenger current source
connected to the “Passenger Bag High” terminal “17”
and allows a known amount of current to flow. B
y
monitoring the voltage difference between the
“Passenger Bag High” and “Passenger Bag Low” the
SRS control unit calculates the combined resistance o
f
the passenger air bag assembly, harness wiring circuits
“Passenger Bag High” and “Passenger Bag Low”
connector terminal contact.
DTC Will Set When
The combined resistance of the passenger air bag
assembly, harness wiring circuits “Passenger Bag High”
and “Passenger Bag Low”, and connector 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 a diagnostic trouble code.


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ISUZU KB P190 2007

9A1-18 RESTRAINT CONTROL SYSTEM

DTC Will Clear When
Resistance value returns 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.
4. This test checks for proper contact and/or corrosion
of the yellow connector terminals.
5. This test checks for a malfunctioning passenger ai
r
bag assembly.
6. This test determines whether the malfunction is due
to a high resistance in the wiring.
Diagnostic Aids

An intermittent condition is likely to be caused by a poor
connection at the passenger air bag assembly harness
connector terminals “1” and “2”, SRS control unit
terminal “17” and “16”, or a poor wire to terminal
connection in circuits “Passenger Bag High” and
“Passenger Bag Low”. 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 “Clea
r
Codes” command is issued and the malfunction is still
present, the DTC will not reappear until the next ignition
cycle.


DTC B0015 (Flash Code 15) Passenger Air Bag 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 air bag squib circuit for open.
2. If a problem is 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 behind the glove box assembly is seated properly.
Is the yellow connector connected properly? Go to Step 4 Seat passenger Air
Bag assembly
yellow connector properly.
Go to Step 7
4
1. Disconnect and inspect the passenger air bag assembly
yellow connector located behind the glove box assembly.
2. If OK, reconnect the passenger air bag assembly connector.
3. Ignition switch is “ON”.
Is DTC B0015 current? Go to Step 5 Go to Step 7
5

1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil and passenger air bag assembly,
yellow connector located at the base of the steering column
and behind the glove box assembly.
3. Connect a 5-8840-2421-0 SRS driver / passenger load tool
and appropriate adapters to the SRS coil and passenger air
bag assembly harness connectors.
4. Ignition switch is “ON”.
Is DTC B0015 Current? Go to Step 6 Ignition switch
“LOCK”.
Replace the
passenger air bag assembly.
Go to Step 7

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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-19

Step Action Yes No
6
1. Ignition switch is at “LOCK”.
2. There has been an increase in the total circuit resistance of
the passenger inflator deployment loop.
3. Use the high resolution ohmmeter mode of the DMM while
checking the circuits “Passenger Bag High” and “Passenger
Bag Low”, and the SRS control unit connector terminal “17”
and “16”, to locate the root cause.
W as a fault found? Replace SRS
harness.
Go to Step 7 Go to Chart A
7

1. Reconnect all components and ensure all components are
properly mounted.
2. Clear the diagnostic trouble codes.
Is This step finished? Repeat the “SRS
Diagnostic System Check” —


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ISUZU KB P190 2007

9A1-20 RESTRAINT CONTROL SYSTEM

DTC B0016 (Flash Code 16) Passenger Air Bag Squib Circuit Low Resistance




RTW 79ALF000301
Circuit Description
W hen the ignition switch is turned to “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”. The
“Passenger Bag Low” terminal “16” is grounded through
a resistor and the passenger current source connected
to the “Passenger Bag High” terminal “17” and allows a
known amount of current to flow. By monitoring the
voltage difference between the “Passenger Bag High”
and “Passenger Bag Low”, the SRS control unit
calculates the combined resistance of the passenger ai
r
bag assembly, harness wiring circuits “Passenger Bag
High” and “Passenger Bag Low” connector terminal
contact.
DTC Will Set When
The combined resistance of the passenger air bag
assembly, harness wiring circuits “Passenger Bag High”
and “Passenger Bag Low”, and connector 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 a diagnostic trouble code.


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ISUZU KB P190 2007

RESTRAINT CONTROL SYSTEM 9A1-21

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 connection of the yellow connector.
4. This test checks for proper operation of the shorting
clip on the yellow connector.
5. This test checks for a malfunctioning passenger ai
r
bag assembly.
6. This test determines whether the malfunction is due
to shortening in the wiring.
Diagnostic Aids

An intermittent condition is likely to be caused by a short
between circuits “Passenger Bag High” and “Passenge
r
Bag Low” or a malfunctioning shorting clip on the
passenger air bag assembly which would require
replacement of the air bag assembly. 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 B0016 (Flash Code 16) Passenger Air Bag Squib Circuit Low Resistance

Step Action Yes No
1 W as the “SRS Diagnostic System Check” performed?
Go to Step 2 Repeat the “SRS
Diagnostic System Check”
2
1. Check the passenger 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 is at “LOCK”.
2. Make sure the passenger air bag assembly yellow connector
located behind the glove box assembly is seated properly.
Is the yellow connector connected properly? Go to Step 4 Seat passenger air
bag assembly
yellow connector properly.
Go to Step 7
4
1. Disconnect and inspect the passenger air bag assembly
yellow connector located behind the glove box assembly.
2. If ok, reconnect the passenger air bag assembly connector.
3. Ignition switch is “ON”.
Is DTC B0016 Current? Go to Step 5 Go to Step 7
5

1. Ignition switch is at “LOCK”.
2. Disconnect the SRS coil and passenger air bag assembly
yellow connector located at the base of the steering column
and behind the glove box assembly.
3. Connect 5-8840-2421-0 SRS driver/passenger load tool and
appropriate adapters to the SRS coil and the passenger air
bag assembly harness connectors.
4. Ignition switch is “ON”.
Is DTC B0016 current? Go to Step 6 Ignition switch
“LOCK”.
Replace the
passenger air bag assembly.
Go to Step 7

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ISUZU KB P190 2007