ESP ISUZU TROOPER 1998 Service Repair Manual

8H±26SECURITY AND LOCKS
StepNo Ye s Action
12The control unit makes lock/unlock response once with interval of
one second.
Is the response complete?
FinishedÐ
13The control unit makes lock/unlock response three times with
interval of one second.
Is the response complete?
FinishedÐ
ID Code Check
This procedure checks how many kinds of ID code are
registered.
Step
ActionYe sNo
11. Open the driver's side door.
2. Turn the starter switch off.
Is the action complete?
Go to Step 2Ð
2Turn the starter switch to ACC position and then off three times
within five seconds after step 1.
Is the action complete within five seconds?
Go to Step 3Finished
3Close the door and then open it two times within ten seconds after
step 2.
Is the action complete within ten seconds?
Go to Step 4Finished
41. Turn the starter switch to ACC position and then off.
2. Close the door and then open it.
NOTE: This step must be performed within ten seconds after step
3.
Is the action complete?
Go to Step 5Finished
5The control unit makes lock/unlock response twice as many the
number of registered ID code with interval of two seconds. (In
case of no registered code, the response is made ten times.)
Is the response complete?
FinishedÐ
Answer Back (Anti±theft Horn
Operation) Change Mode
Anti±theft horn, as an answer back function for the
transmitter operation, chages from available into
unavailing or from unavailing into available by this
procedure.
Step
ActionYe sNo
1Open the driver's side door.
Is the action complete?
Go to Step 2Ð
2Lock the door and then unlock it three times within ten seconds
after step 1.
Is the action complete within five seconds?
Go to Step 3Finished
3Close the door and then open it two times within ten seconds after
step 2.
Is the action complete within ten seconds?
Go to Step 4Finished

SECURITY AND LOCKS8H±27
StepNo Ye s Action
41. Lock the door and unlock it three times.
2. Close the door and then open it.
NOTE: This step must be performed within ten seconds after step
3.
Is the action complete?
Go to Step 5Finished
5Answer back mode changes.
Is this step complete?
Go to Step 6Go to Step 7
6The control unit makes lock/unlock response once with interval of
one second.
Is the response complete?
FinishedÐ
7The control unit makes lock/unlock response three times with
interval of one second.
Is the response complete?
FinishedÐ
Anti±theft & Keyless Entry Control
Unit/Transmitter Replacement
Anti±theft & Keyless Entry Control Unit
Replacement
1. Remove and install the control unit.

Refer to Anti±theft & Keyless Entry Control Unit
Removal and Installation in this section.
2. Register ID code.

Refer to ID Code Registration in this section.
3. Check that the keyless entry system works normally.
Transmitter Replacement
1. Prepare a new transmitter.
2. Regiter ID code.

Refer to ID Code Registration in this section.
3. Check that the keyless entry system works normally.
Transmitter Battery Replacement
1. Remove a screw to remove the cover.
2. Remove the batteries.
3. Set the new batteries into the transmitter.
4. Install the cover to the transmitter.
5. Check that the keyless entry system works normally.

RESTRAINT CONTROL SYSTEM 9J1±4
System Schematic
D09RW014
SRS Diagnostic System Check
The diagnostic procedures used in this section are
designed to find and repair SRS malfunctions. To get the
best results, it is important to use the diagnostic charts
and follow the sequence listed below:
A. Perform the ªSRS Diagnostic System Check.º
The ªSRS Diagnostic System Checkº must be the
starting point of any SRS diagnostics. The ªSRS
Diagnostic System Checkº checks for proper ªAIR
BAGº warning lamp operation, the ability of the SDM
to communicate through the ªSerial Dataº line and
whether SRS diagnostic trouble codes exist.
B. Refer to the proper diagnostic chart as directed by the
ªSRS Diagnostic System Check.º
The ªSRS Diagnostic System Checkº will lead you to
the correct chart to diagnose any SRS malfunctions.
Bypassing these procedures may result in extended
diagnostic time, incorrect diagnosis and incorrect
parts replacement.
C. Repeat the ªSRS Diagnostic System Checkº after any
repair or diagnostic procedures have been
preformed.
Performing the ªSRS Diagnostic System Checkº after
all repair or diagnostic procedures will ensure that the
repair has been made correctly and that no other
malfunctions exist
Circuit Description
When the ignition switch is first turned ªONº, ªIgnition 1º
voltage is applied from the ªC±21º fuse to the SDM at the
ªIgnition 1º input terminals ª12º. The SDM responds by
flashing the ªAIR BAGº warning lamp turn on 3.5 seconds,
while performing tests on the SRS.
Notes On System Check Chart:
1. The ªAIR BAGº warning lamp should turn on 3.5
seconds after ignition is first turned ªONº.
2. After the ªAIR BAGº warning lamp turn on 3.5
seconds, it should turn ªOFFº
3. This test checks for the proper operation of the
ªSerial Dataº line. This test will also determine
whether history diagnostic trouble codes are stored
and, if so, identify them.
4. Improper operation of the ªAIR BAGº warning lamp
is indicated. This test differentiates a warning lamp
stays ªONº condition from a warning lamp does not
come ªONº condition.
5. This test checks for proper operation of the ªSerial
Dataº line. This test will also identify the stored
diagnostic trouble codes and whether they are
current or history.
Diagnostic Aids:
The order in which diagnostic trouble codes are
diagnosed is very important. Failure to diagnose the

RESTRAINT CONTROL SYSTEM 9J1±8
Chart B ªAIR BAGº Warning Lamp Comes ªONº Steady
D09RW014
Circuit Description:
When the ignition switch is first turned ªONº, ªIgnition 1º
voltage is applied from the ªC±10º fuse to ªAIR BAGº,
warning lamp which is connected to ªSRS Warning
Lampº, terminal ª7º. The ªC±21º fuses apply system
voltage to the ªIgnition 1º inputs, terminals ª12º. The SDM
responds by turning on the ªAIR BAGº warning lamp 3.5
seconds. If ªIgnition 1º is less than 9 volts, the ªAIR BAGº
warning lamp will come ªONº 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 ªIgnition 1º circuit
to the SDM.
3. This test checks for the voltage of ªIGNITION 1º.
4. This test determines whether the malfunction is a
short to ground in IB04±WHT/RED.

RESTRAINT CONTROL SYSTEM 9J1±10
Chart C ªAIR BAGº Warning Lamp Does Not Come ªONº Steady
D09RW014
Circuit Description:
When the ignition switch is first turned ªONº, ªIgnition 1º
voltage is applied from the ªC±10º fuse to the ªAIR BAGº
warning lamp which is connected to ªSRS Warning
Lampº, terminal ª7º. The ªC±21º fuse apply system
voltage to the ªIgnition 1º inputs, terminals ª12º. The SDM
responds by turning on the ªAIR BAGº warning lamp 3.5
seconds. If ªIgnition 1º is more than 16 volts, the ªAIR
BAGº warning lamp will be still ªOFFº 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 SDM
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 IB04±WHT/RED circuit and
checks for a short in the IB04±WHT/RED circuit to
B+.
8. This test checks for a short from the SDM warning
lamppower feed circuit to ground.
9. This test determines whether the short to ground is
due to a short in the wiring.

9J1±13
RESTRAINT CONTROL SYSTEM
DTC 15 Passenger 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. ªPassenger Bag Lowº terminal ª16º is grounded
through a resister and the passenger current source
connected to ªPassenger Bag Highº terminal ª15º allows a
known amount of current to flow. By monitoring the
voltage difference between ªPassenger Bag Highº and
ªPassenger Bag Lowº the SDM calculates the combined
resistance of the passenger air bag assembly, harness
wiring IB07±YEL/GRN and IB08±YEL/RED connector
terminal contact.
DTC Will Set When:
The combined resistance of the passenger air bag
assembly, harness wiring IB07±YEL/GRN and
IB08±YEL/RED, 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 air
bag 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 ª15º and
ª16º, or a poor wire to terminal connection in
IB07±YEL/GRN and IB08±YEL/RED. This test for this
diagnostic trouble code is only run while the ªAIR BAGº

9J1±15
RESTRAINT CONTROL SYSTEM
DTC 16 Passenger 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. ªPassenger Bag Lowº terminal ª16º is grounded
through a resistor and the passenger current source
connected to ªPassenger Bag Highº terminal ª15º allows a
known amount of current to flow. By monitoring the
voltage difference between ªPassenger Bag Highº and
ªPassenger Bag Lowº, the SDM calculates the combined
resistance of the passenger air bag assembly, harness
wiring IB07±YEL/GRN and IB08±YEL/RED connector
terminal contact.
DTC Will Set When:
The combined resistance of the passenger air bag
assembly, harness wiring IB07±YEL/GRN and
IB08±YEL/RED, 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 air bag
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 IB07±YEL/GRN and IB08±YEL/RED, 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 ªAIR BAGº warning lamp is performing the bulb

9J1±17
RESTRAINT CONTROL SYSTEM
DTC 17 Passenger 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 flowing in the deployment loop. This produces
proportional voltage drops in the loop. By monitoring the
voltage difference between ªPassenger Bag Highº and
ªPassenger Bag Lowº, the SDM calculates the combined
resistance of the passenger air bag assembly, harness
wiring IB07±YEL/GRN AND IB08±YEL/RED, and
connector terminal contact.
DTC Will Set When:
The voltage difference between ªPassenger Bag Highº
terminal ª15º and ªPassenger Bag Lowº terminal ª16º 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 ªPassenger Bag Highº
terminal ª15º and ªPassenger Bag Lowº terminal ª16º is
below a specified 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.
4. This test cheeks for proper contact and/or corrosion
of the shorting clip in the yellow 2±pin connector
terminals.
5. The test checks for a malfunctioning passenger air
bag assembly.
6. This test determines whether the open 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 terminalsª2º and ª3º, SDM terminals ª15º and
ª16º, or an open in IB07±YEL/GRN and IB08±YEL/RED.

9J1±19
RESTRAINT CONTROL SYSTEM
DTC 18 Passenger 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 voltages at ªDriver Bag Lowº
terminal ª4º and ªPassenger Bag Lowº terminal ª16º to
detect short 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.
Once these conditions are met and the voltage at
ªPassenger Bag Lowº is below a specified value, DTC 18
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 air bag assembly yellow 2±pin connector
behind glove box assembly.
4. This test determines whether the malfunction is in
IB07±YEL/GRN.
5. This test determines whether the malfunction is in
IB08±YEL/RED.
Diagnostic Aids:
An intermittent condition is likely to be caused by a short
to ground in the passenger air bag assembly circuit.
Inspect IB07±YEL/GRN and IB08±YEL/RED carefully for
cutting or chafing. If the wiring pigtail of the passenger air
bag assembly is damaged, the component must be
replaced.

9J1±21
RESTRAINT CONTROL SYSTEM
DTC 19 Passenger 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 voltages at ªDriver Bag Lowº
terminal ª4º and ªPassenger Bag Lowº terminal ª16º to
detect short to B+ in the air bag 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 Bag Lowº is above a specified value, DTC 19
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 19 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 malfunction is in
the SDM.
3. This test isolates the malfunction to one side of the
passenger air bag assembly yellow 2±pin connector
behind glove box assembly.
4. This test determines whether the malfunction is in
IB07±YEL/GRN.
5. This test determines whether the malfunction is in
IB08±YEL/RED.
Diagnostic Aids:
An intermittent condition is likely to be caused by a short
to B+ in the passenger air bag assembly circuit. Inspect
IB07±YEL/GRN and IB08±YEL/RED carefully for cutting
or chafing. If the wiring pigtail of the passenger air bag
assembly is damaged, the component must be replaced.
A careful inspection of IB07±YEL/GRN and
IB08±YEL/RED, including the passenger air bag
assembly pigtail is essential to ensure that the
replacement SDM will not be damaged.