ESP ISUZU TROOPER 1998 Service Repair Manual

9J1±23
RESTRAINT CONTROL SYSTEM
DTC 21 Driver Deployment Loop Resistance High
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM then proceeds with the ªResistance
Measurement Testº ªDriver Bag Lowº terminal ª4º is
grounded through a current sink and the driver current
source connected to ªDriver Bag Highº terminal ª3º allows
a known amount of current to flow. By monitoring the
voltage difference between ªDriver Bag Highº and ªDriver
Bag Lowº, the SDM calculates the combined resistance
of the driver air bag assembly, SRS coil assembly,
harness wiring IB05±YEL and IB06±YEL/BLK, and
connector terminal contact.
DTC Will Set When:
The combined resistance of the driver air bag assembly,
SRS Coil assembly, harness wiring IB05±YEL and
IB06±YEL/BLK, and connector terminal contact is above
a specified value. This test run once each ignition cycle
during the ªResistance Measurement Testº when:
1. No ªhigher priority faultsº are detected during
ªTurn±ONº
2. ªIgnition 1º voltage is in the specified value.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets
DTC 21.
DTC Will Clear When:
The ignition switch is turned ªOFFº.
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 SDM.
3. This test verifies proper connection of the yellow
2±pin connector at the base of the steering column.
4. This test checks for proper contact and/or corrosion
of the 2±pin connector terminals at the base of
steering column.
5. This test isolate the malfunction to one side of the
SRS coil assembly yellow 2±pin 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.

RESTRAINT CONTROL SYSTEM 9J1±26
DTC 22 Driver Deployment Loop Resistance Low
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM then proceeds with the ªResistance
Measurement Testº ªDriver Bag Lowº terminal ª4º is
grounded through a current sink and the driver current
source connected to ªDriver Bag Highº terminal ª3º allows
a known amount of current to flow. By monitoring the
voltage difference between ªDriver Bag Highº and ªDriver
Bag Lowº the SDM calculates the combined resistance of
the driver air bag assembly, SRS coil assembly, harness
wiring IB05±YEL and IB06±YEL/BLK and connector
terminal contact.
DTC Will Set When:
The combined resistance of the driver air bag assembly,
SRS Coil assembly, harness wiring IB05±YEL and
IB06±YEL/BLK and connector terminal contact is above a
specified value. This test is run once each ignition cycle
during the ªResistance Measurement Testº when:
1. No ªhigher priority faultsº are detected during
ªTurn±ONº
2. ªIgnition 1º voltage is in the specified value.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets
DTC 22.
DTC Will Clear When:
The ignition switch is turned ªOFF.º
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 SDM.
3. This test verifies proper connection of the yellow
2±pin connector at the base of the steering column.
4. This test checks for proper operation of the shorting
clip in the yellow 2±pin connector.
5. This test isolate the malfunction to one side of the
SRS coil assembly yellow 2±pin connector located
at the base of 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 IB05±YEL or IB06±YEL/BLK or a

9J1±29
RESTRAINT CONTROL SYSTEM
DTC 24 Driver Deployment Loop Short To Ground
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM monitors the voltage at ªDriver Bag Lowº
terminal ª4º and ªpassenger Bag Lowº terminal ª16º to
detect shorts to ground in the air bag assembly circuits.
DTC Will Set When:
Neither of the two air bag assemblies is open.
ªIgnition 1º is within the normal operating voltage range.
This test is run once each ignition cycle and ªContinuous
Monitoringº. Once these conditions are met and the
voltage at ªDriver Bag Lowº is below a specified value,
DTC 24 will set.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets a
diagnostic trouble code.
DTC Will Clear When:
The malfunction is no longer occurring and the ignition is
turned ªOFFº.
DTC Chart Test Description:
Number(s) below refer to step number(s) on the
diagnostic chart:
2. This test determines whether the SDM 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
IB05±YEL.
5. This test determines whether the malfunction is in
IB06±YEL/BLK.
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 in the driver air bag assembly circuit. Inspect
IB05±YEL and IB06±YEL/BLK carefully for cutting or
chafing.

9J1±31
RESTRAINT CONTROL SYSTEM
DTC 25 Driver Deployment Loop Short To B+
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM monitors the voltage at ªDriver Bag Lowº
terminal ª4º and ªPassenger Bag Lowº terminal ª16º to
detect shorts to B+ in the air bag assembly circuits.
DTC Will Set When:
ªIgnition 1º is in the normal operating voltage range. This
test is run once each ignition cycle and ªContinuous
monitoringº. Once these conditions are met and the
voltage at ªDriver Bag Lowº is above a specified value,
DTC 25 will set.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets
DTC 25 and also DTC 71
DTC Will Clear When:
The SDM is replaced.
DTC Chart Test Description:
Number(s) below refer to step number(s) on the
diagnostic chart:2. This test determines whether the SDM is
malfunctioning.
3. This test isolates the malfunction to one side of the
driver air bag assembly yellow 2±pin connector at
the base of steering column.
4. This test determines whether the malfunction is in
IB05±YEL.
5. This test determines whether the malfunction is in
IB06±YEL/BLK.
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 B+ in the driver air bag assembly circuit. Inspect
IB05±YEL and IB06±YEL/BLK carefully for cutting or
chafing. If the wiring pigtail of the driver air bag assembly
and SRS coil assembly is damaged, the components
must be replaced. A careful inspection of IB05±YEL and
IB06±YEL/BLK, including the SRS coil assembly and
driver air bag assembly is essential to ensure that the
replacement SDM will not be damaged.

9J1±33
RESTRAINT CONTROL SYSTEM
DTC 26 Driver Deployment Loop Open
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges.
During ªContinuous Monitoringº diagnostics, a fixed
amount of current is following in the deployment loop.
This produces proportional voltage drops in the loop. By
monitoring the voltage difference between ªDriver Bag
Highº and ªDriver Bag Lowº, the SDM calculates the
combined resistance of the driver air bag assembly, SRS
coil assembly, harness wiring IB05±YEL and
IB06±YEL/BLK, and connector terminal contact.
DTC Will Set When:
The voltage difference between ªDriver Bag Highº
terminal ª3º and ªDriver Bag Lowº terminal ª4º is above or
equal to a specified value for 500 milliseconds during
ªContinuous Monitoringº.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets a
diagnostic trouble code.
DTC Will Clear When:
The voltage difference between ªDriver Bag Highº
terminal ª3º and ªDriver Bag Lowº terminal ª4º is below aspecified value for 500 milliseconds during ªContinuous
Monitoringº.
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 SDM.
3. This test verifies proper connection of the yellow
2±pin connector at the base of the steering column.
4. This test checks for proper contact and/or corrosion
of the yellow 2±pin connector at the base of the
steering column.
5. This test isolates the malfunction to one side of the
SRS coil assembly yellow 2±pin connector located
at the base of steering column.
6. This test determines whether the open is 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 the driver air bag assembly harness 2±pin
connector terminals ª1º and ª2º at the top of the steering
column, SRS coil assembly harness 2±pin connection
terminals ª1º and ª2º, SDM terminals ª3º and ª4º, or an
open in IB05±YEL and IB06±YEL/BLK.

9J1±39
RESTRAINT CONTROL SYSTEM
DTC 61 Warning Lamp Circuit Failure
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, battery voltage is
applied to the ªAIR BAGº warning lamp and to the ªIgnition
1º input terminal ª12º. The SDM responds by turning on
the ªAIR BAGº warning lamp 3.5 seconds. The SDM
monitors the lamp driver output by comparing the output
state at ªSRS Warning Lampº terminal ª7º to the
microprocessor commanded state. When ªIgnition 1º is in
the specified value, and the output state does not match
the commanded state of the lamp driver for 500
milliseconds, DTC 61 is set.
DTC Will Set When:
ªIgnition 1º voltage is in the specified value and the output
state at the ªSRS Warning Lampº terminal does not matchthe commanded state of the lamp driver for 500
milliseconds. This test is run every 100 milliseconds
during ªContinuous Monitoringº tests and once per each
ignition cycle at the beginning.
Action Taken:
SDM attempts to turn ªONº the ªAIR BAGº warning lamp
and sets a diagnostic trouble code.
DTC Will Clear When:
The ignition switch is turned ªOFF.º
Diagnostic Aids:
Refer to Charts B and C to diagnose warning lamp circuit
malfunctions.

9J1±43
RESTRAINT CONTROL SYSTEM
DTC 29 Passenger Pretensioner Loop Short To Ground
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
pretensioner loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM monitors the voltages at ªDriver Belt Lowº
terminal ª10º and ªPassenger Belt Lowº terminal ª22º to
detect short to ground in the pretensioner assembly
circuits.
DTC Will Set When:
Neither of the air bag and the pretensioner belt are open.
ªIgnition 1º is within the normal operating voltage range.
Once these conditions are met and the voltage at
ªPassenger Belt Lowº is below a specified value, DTC 29
will set. This test is run once each ignition cycle and
ªContinuous Monitoringº.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets a
diagnostic trouble code.
DTC Will Clear When:
This malfunction is no longer occurring and the ignition
switch is turned ªOFFº.
DTC Chart Test Description:
Number(s) below refer to circled number(s) on the
diagnostic chart.
2. This test determines whether the SDM is
malfunctioning.
3. This test isolates the malfunction to one side of the
passenger pretensioner assembly yellow 2±pin
connector at the base of the passenger seat.
4. This test determines whether the malfunction is in
IB15±BLU/BLK.
5. This test determines whether the malfunction is in
IB16±BLU/ORG.
Diagnostic Aids:
An intermittent condition is likely to be caused by a short
to ground in the passenger pretensioner assembly circuit.
Inspect IB15±BLU/BLK and IB16±BLU/ORG carefully for
cutting or chafing. If the wiring pigtail of the passenger
pretensioner assembly is damaged, the component must
be replaced.

9J1±45
RESTRAINT CONTROL SYSTEM
DTC 31 Passenger Pretensioner Loop Resistance High
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests ªIgnition 1º, and
deployment loop voltages are measured to ensure they
are within their respective normal voltage ranges. The
SDM then proceeds with the ªResistance Measurement
Testº. ªPassenger Belt Lowº terminal ª10º is grounded
through a resister and the passenger current source
connected to ªPassenger Belt Highº terminal ª9º allows a
known amount of current to flow. By monitoring the
voltage difference between ªPassenger Belt Highº and
ªPassenger Belt Lowº the SDM calculates the combined
resistance of the passenger air bag assembly, harness
wiring IB15±BLU/BLK and IB16±BLU/ORG connector
terminal contact.
DTC Will Set When:
The combined resistance of the passenger pretensioner
assembly, harness wiring IB15±BLU/BLK and
IB16±BLU/ORG, and connector terminal contact is
above a specified value. This test is run once each
ignition cycle during the ªResistance Measurement Testº
when:
1. No ªhigher priority faultsº are detected during
ªTurn±ONº,
2. ªIgnition 1º voltage is in the specified value.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets a
diagnostic trouble code.
DTC Will Clear When:
The ignition switch is turned ªOFF.º
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 SDM.
3. This test verifies proper connection of the yellow
2±pin connector.
4. This test checks for proper contact and/or corrosion
of the yellow 2±pin connector terminals.
5. The test checks for a malfunctioning passenger
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 air bag assembly harness
connector terminals ª1º and ª2º, SDM terminal ª9º and
ª10º, or a poor wire to terminal connection in
IB15±BLU/BLK and IB16±BLU/ORG. This test for this
diagnostic trouble code is only run while the ªAIR BAGº

9J1±47
RESTRAINT CONTROL SYSTEM
DTC 32 Passenger Pretensioner loop Resistance Low
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests ªIgnition 1º, and
pretensioner loop voltages are measured to ensure they
are within their respective normal voltage ranges. The
SDM then proceeds with the ªResistance Measurement
Testº. ªPassenger Belt Lowº terminal ª10º is grounded
through a resistor and the passenger current source
connected to ªPassenger Belt Highº terminal ª9º allows a
known amount of current to flow. By monitoring the
voltage difference between ªPassenger Belt Highº and
ªPassenger Belt Lowº, the SDM calculates the combined
resistance of the passenger air bag assembly, harness
wiring IB15±BLU/BLK and IB16±BLU/ORG connector
terminal contact.
DTC Will Set When:
The combined resistance of the passenger air bag
assembly, harness wiring IB15±BLU/BLK and
IB16±BLU/ORG, and connector terminal contact is
above a specified value. This test is run once each
ignition cycle during the ªResistance Measurement Testº
when:
1. No ªhigher priority faultsº are detected during
ªTurn±ONº,
2. ªIgnition 1º voltage is in the specified value.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets a
diagnostic trouble code.
DTC Will Clear When:
The ignition switch is turned ªOFF.º
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 SDM.
3. This test verifies connection of the yellow 2±pin
connector.
4. This test cheeks for proper operation of the shorting
clip in the yellow 2±pin connector.
5. The test checks for a malfunction passenger
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 IB15±BLU/BLK and IB16±BLU/ORG, or a
malfunctioning shorting clip on the passenger
pretensioner assembly which would require replacement
of the pretensioner assembly. The test for this diagnostic
trouble code is only run while ªAIR BAGº warning lamp is

9J1±49
RESTRAINT CONTROL SYSTEM
DTC 33 Passenger Pretensioner Loop Short To Voltage
D09RW014
Circuit Description:
When the ignition switch is turned ªONº, the SDM will
perform tests to diagnose critical malfunctions within
itself. Upon passing these tests, ªIgnition 1º, and
pretensioner loop voltages are measured to ensure they
are within their respective normal voltage ranges.
The SDM monitors the voltages at ªDriver Belt Lowº
terminal ª10º and ªPassenger Belt Lowº terminal ª22º to
detect short to B+ in the pretensioner assembly circuits.
DTC Will Set When:
ªIgnition 1º is within the normal operating voltage range.
Once these conditions are met and the voltage at
ªPassenger pretensioner Lowº is above a specified value,
DTC 33 will set. This test is run once each ignition cycle
and ªContinuous Monitoringº.
Action Taken:
SDM turns ªONº the ªAIR BAGº warning lamp and sets
DTC 33.
DTC Will Clear When:
The malfunction is no longer occurring and the ignition is
turned ªOFFº.
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 SDM.
3. This test isolates the malfunction to one side of the
passenger pretensioner assembly yellow 2±pin
connector at the base of the passenger seat.
4. This test determines whether the malfunction is in
IB15±BLU/BLK.
5. This test determines whether the malfunction is in
IB16±BLU/ORG.
Diagnostic Aids:
An intermittent condition is likely to be caused by a short
to B+ in the passenger pretensioner assembly circuit.
Inspect IB15±BLU/BLK and IB16±BLU/ORG carefully for
cutting or chafing. If the wiring pigtail of the passenger
pretensioner assembly is damaged, the component must
be replaced. A careful inspection of IB15±BLU/BLK and
IB16±BLU/ORG, including the passenger pretensioner
assembly pigtail is essential to ensure that the
replacement SDM will not be damaged.