warning ISUZU TROOPER 1995 Workshop Manual

9J-68 Supplemental Restraint System
DTC 25 {PAGE 2 OF 2)
INITIATOR CIRCUIT SHORT TO IGNITION
CIRCUIT DESCRIPTION
During the "Initiator Assembly Resistance Test" the
DERM grounds the "Driver
Side Low" terminal "88" and
measures the voltage at "Driver Side Low" and
"Passenger Side Low." The DERM then grounds
"Passenger Side Low" terminai"B7" and again measures
the voltage at "Driver
Side Low" and "Passenger Side
Low." For a properly operating circuit the voltage
measures the voltage measurements during each of
these tests
will be below a specified value. When the
voltages measured at both "Driver Side Low" and
"Passenger Side Low" are above a specified value during
both tests DTC 25 is set.
DTC WILL SET WHEN
The voltages measured at both "Driver Side Low" and
"Passenger Side Low" are above a specified value while
the DERM attempts to ground each of these terminals.
This test is run during the
"Initiator Assembly Resistance
Test" and the "10 Minute Loop Test'' when: 1) "higher
priority faults" are detected during
"Turn-ON", 2) No
"higher priority
faults" are detected during "continuous
Monitoring" for one second, 3) No
"Crank" signal present,
4)
"Ignition 1" voltage is above a specified value.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
a diagnostic trouble code.
....
DTC WILL CLEAR WHEN
The voltages measured at either "Driver Side Low" or
"Passenger Side Low" is below a specified value while
the DERM ground either of these terminals.
CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
1
0. This test checks for a short from the high side of the
passenger deployment loop to 8+.
11. This test checks for a short from the high side of the
passenger deployment loop to 8+.
12. This test checks for a short from the low side of the
driver deployment loop or passenger deployment
loop to B+.
DIAGNOSTIC AIDS
This diagnostic trouble code can only be set when the
malfunction is present as the ignition switch is turned
"ON." After the "Initiator Assembly Resistance Test" is
completed a short to B+ in the steering column, CKT
1819, CKT 1820 or CKT 1824
will cause DTC 24 to set.
When a scan tool "Clear Codes" command is issued and
the malfunction is
still present, the DTC will not reappear
for ten minutes or until the next ignition cycle.
SRS-1 JOINT CONNECTlON ,l 10 1101 ERM
PASS.3eVLR PASS. SOURCE SENSE
PASS SIDe HIGH PASS SIDe LOW
SERIAL DATA
SRS INDICA TOR
II

9J-70 Supplemental Restraint System
DTC26
DRIVER INITIATOR CIRCUIT OPEN
CIRCUIT DESCRIPTION
When there is an open in the driver inflator module or the
SRS coil assembly the resistance between "Driver Side
High" terminal "89" and "Driver Side Low" terminal "88"
increases. This causes a larger voltage drop from the
"Driver
Side High" to the "Driver Side Low" across a
resistor inside the DERM which connects these two
terminals together. The increase in the voltage difference
between "Driver
Side High" and "Driver Side Low" is
detected by the DERM during the "Continuous
Monitoring" tests and DTC 26 is sets.
DTC WILL SET WHEN
The voltage difference between "Driver Side High"
terminal "89" and "Driver Side Low" terminal "88" is
above or
equal to a specified value for 500 milliseconds.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
a diagnostic
trouble code.
TO IGNITION FUSE SRS C-23 lOA , ...
DTC WILL TEST WHEN
The voltage difference between "Driver Side High"
terminal "89" and "Driver Side Low" terminal "88" is
below a specified value for 500 milliseconds.
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 driver inflator module.
3. This test determines whether the malfunction is in
the SRS coil assembly.
4. This test determines whether the malfunction is in
the SRS HARNESS.
DIAGNOSTIC AIDS
This diagnostic trouble code will only set when there is
an improper connection of either the
yellow 2-way
connector near the base of steering column or the yellow
2-way connector at the top of the steering column, an
open SRS coil assembly or an open inflator module.
SRS·l
JOINT CONNECTION ,.,. IGNITION 1 SWITCH
FUSE~
1GrJ;~ION-- SRS C-24 lOA , ... R D
I----'18"'34'----T---7-3--7-+---'"11134..._-BLI DRIVER 36VLR PASS. 36VLR PASS. SOURCE SENSE
REDUNDAT INDICATOR GROUND
PASS SIDE HIGH
PASS SIDE LOW
SERIAL DATA
DRIVER SIDE HIGH DRIVER SlOE LOW REDUNDANT INDICATOR IGNITION 1
SRS INDICATOR
Ill

9J-72 Supplemental Restraint System
DTC28
CURRENT SINK OR SOURCE FAILURE
CIRCUIT DESCRIPTION
During the "Initiator Assembly Resistance Test" the
DERM grounds the "Passenger Side Low" terminal
"87"
and turns "ON" the driver current source at

the "Driver
Side High"terminal "89". The DERM then grounds the
"Driver Side Low" terminal
"88" and turns "ON" the
passenger current source at the "Passenger Side High"
terminal "A7". During each of these tests the DERM
monitors voltage at "Driver Side Low," "Passenger Side
Low," the difference between "Driver Side High" and
"Driver Side Low" and the difference between
"Passenger Side High" and "Passenger Side Low."
When the measured values are outside the expected
range DTC 28 is set.
DTC WILL SET WHEN
The voltage measured at "Driver Side Low" or
"Passenger Side Low'' is below a specified value while its
respective initiator resistance is
in range or when the
voltage measured at "Driver Side
Low" or "Passenger
Side Low" is above a specified value. This test is
run once
each
ignition cycle during the "Initiator Assembly
Resistance Tesf' when: 1) No "higher priority faults" are
detected during
"Turn-oN," 2) No "higher priority faults"
are detected during "Continuous Monitoring" for one
second, 3) No
"Crank" signal present, 4) "Ignition 1"
voltage is above a specified value.
, ...
ACTION TAKEN
DERM turns "ON the "AIR BAG" warning lamp and sets
a diagnostic trouble code.
DTC WILL CLEAR WHEN
The ignition switch is turned "OFF."
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks whether malfunction is in the wiring
harness. The wiring harness malfunction would be a
high resistance rather than an open. An open would
set a different diagnostic trouble code.
3. This test determines whether the malfunction is in
the wiring harness. The wiring harness malfunction
would be a high resistance rather than an open.
An
open would set a different diagnostic trouble code
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
wire to terminal connection
in CKT 1 B18C or CKT 1836.
When a scan tool
"Clear Codes" command is issued and
the malfunction is still present, the DTC will not reappear
for ten minutes or until the next ignition cycle.
SRS-1 JOINT CONNECTION 10 11508
IGJ~oN-_;F,:::U:;SE~--t\:__-!!£'"'L-­SWITCH SRS C-22 10A 11511 1812 181l
Bl RED
IIIII

9J-74 Supplemental Restraint System
---~


DTC31 \"'
DRIVER LOOP ENERGY RESERVE FEED OPEN
CIRCUIT DESCRIPTION
During the "Continuous Monitoring" tests the DERM
monitors the
voltage at "Driver Source Sense" terminal
"AS." When the circuit is operating normally the
measured voltage will be slightly less than "Driver 36
VLR."
If the "Driver 36 VLR" circuit opens the voltage
measured at "Driver Source Sense" will decrease to
slightly less than "Ignition 1" voltage. When the voltage
measured at "Driver Source Sense" is within a specified
range of
"Ignition 1" for SOO milliseconds DTC 31 is set.
DTC WILL SET WHEN
The voltage measured at "Driver Source Sense" terminal
"AS"
is within a specified range of "Ignition 1" for SOO
milliseconds. This test is run every 100 milliseconds
during "Continuous Monitoring" tests.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamps and sets
a diagnostic
trouble code.
DTC WILL CLEAR WHEN
The voltage measured at "Driver Source Sense" terminal
"AS"
is outside the specified range of "Ignition 1" which
sets the diagnostic
trouble code, for SOO milliseconds.
TO IGNITION SWITCH
FUSE! SRS C-24 lOA , ... R D
FUSE SRS C-23 IDA , ...
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks for an open in the "Driver 36VLR"
circuit.
3. This test checks for a high resistance, but not an
open, in the "Driver Source Sense" circuit.
4. This test checks for a short from the "Driver Source
Sense" circuit to 8+.
s. This test determines whether the malfunction is due
to the
dual pole arming sensor.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection at arming sensor
terminal "4" or "6", poor
connection at DERM
terminal "A4" or "AS", an open in
CKT 1811 or CKT 1812, or an open inside the dual pole
arming sensor.
IGNITION1
IGNITION1
DRIVER SOURCE SENSE DRIVER 38VLR PASS.3eVLR PASS. SOURCE SENSE
PASS SIDE HIGH
PASS SIDE LOW
SPARE/LPS
SERIAL DATA
SRS INDICATOR
..

9J-76 Supplemental Restraint System
DTC34
DUAL POLE ARMING SENSOR IGNITION FEED OPEN
CIRCUIT DESCRIPTION
During the "turn-ON" tests, performed at the beginning
of each ignition cycle, the DERM delays the charging of
the
"Driver 36 VLR" and "Passenger 36 VLR" power
supplies.
While the delay is active the DERM measures
the voltage at the "Driver VLR" terminal "A4" ,
"Passenger 36 VLR" terminal "A3", "Driver Source
sense" terminal "AS", and "Passenger Source Sense"
terminal "A6". When the voltage measured at the two "36
VLR" power supplies indicates they are in a discharged
state and the voltage measured at each
"Source Sense"
terminal is a specified amount below "Ignition 1" voltage
DTC34 is set.
DTC WILL SET WHEN
With both "36 VLR" power supplies in a discharged state,
the voltage measured at "Driver
Source Sense" terminal
"AS" and "Passenger Source Sense" terminal "A6" are
simultaneously a specified amount below
"Ignition 1"
voltage and no "higher priority faults" are detected. This
test is run once each ignition cycle during the "Turn-ON"
tests while the "36
VLR Delay" is active.
ACTION TAKEN
DERM turns "ON" the AIR BAG" warning lamp and sets
a diagnostic trouble code.
DTC WILL CLEAR WHEN
With both "36 VLR" power supplies in a discharged state,
the voltage measured at specified range of
"Ignition 1"
voltage. When
neither the failure nor clear conditions are met, the
state of the diagnostic trouble code from the previous
ignition cycle is used.
DTC 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
between the
splice and the dual pole arming sensor.
3. This test determines whether the malfunction is
internal to the dual pole arming sensor.
4. This test checks for an open in fuse C-24.
s. This test checks for a short from CKT 1809 to ground.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by an
improper connection at dual pole arming sensor terminal
"3" or "6" and "7" improper connection at DERM terminal
"AS" or "A6", open ignition feed to the dual pole arming
sensor, open "Driver
Source Sense" circuit and open
"Passenger
Source Sense" circuit, or malfunctioning
dual pole arming sensor ignition diodes. The test for this
diagnostic trouble code is only run while the "AIR
BAG"warning lamp is performing the bulb check. When
a scan tool "Clear Code" command is issued and the
malfunction
is still present, the DTC will not reappear
until the ignition switch is turned
"OFP' for at least two
minutes with the entire
SRS connected and then the
ignition switch is turned
"ON."
Ill

9J-78 Supplemental Restraint System
DTC35 ~
DISCRIMINATING SENSOR OPEN OR MISSING
CIRCUIT DESCRIPTION
During normal, non-deployment operation of SRS a
small amount of current flows through both the driver and
passenger deployment loops.The diagnostic resistors
within the dual pole arming sensor and the discriminating
sensors along with the resistance of the inflator modules
cause voltage drops within the deployment loops.The
DERM monitors the voltage at "Driver Side
Low" terminal
"B8" and "Passenger Side Low" terminal "B7' to detect
shorts or opens within the deployment loops.When the
measured voltage at either terminal is within a specified
percentage of its respective
"36 VLR" power supply
voltage for
500 milliseconds DTC 35 is set.
DTC WILL SET WHEN
The voltage measured at "Driver Side Low" terminal "B8"
and "Passenger Side Low" terminal "B7" is within a
specified percentage
of its respective "36 VLR"a power
supply voltage for
500 milliseconds. This test is run every
1
00 milliseconds during the "Continuous Monitoring"
tests.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
a diagnostic trouble code.
...
DTC WILL CLEAR WHEN
The voltages measured at "Driver Side Low" terminal
"B8" and "Passenger Side Low" terminal "B7" are both
above or
below the respective "36 VLR" power supply
voltage which sets
DTC 35.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks for an open inside the forward LH
discriminating sensor.
3. This test checks for an open inside the
Eng-ROOM(forward LH discriminating sensor
Jumper) HARNESS.
4. This test checks for an open inside the forward RH
discriminating sensor.
5. This test checks for an open inside the Engine room
(forward
RH Discriminating Sensor Jumper)
DIAGNOSTIC AIDS
An intermittent condition is likely to be an improper
connection at any of the discriminating sensor terminals,
an open in either ground feed to the discriminating
sensors,
an open discriminating sensor interconnect
ciircuit, increased resistance
of any discriminating
sensor or decreased resistance of the dual pole arming
sensor.
SRS-1 JOINT CONNECTION ,, .
DRIVER 38VLA PASS. 38VLA PASS. SOURCE SENSE
REDUNDAT INDICATOR GROUND
PASS SIDE HIGH
f---""------o~---4--'T--:f----7-------'..,_-BLKJBLU f---.!W...----o~---4--'T--:)--ITO ~~tc~~BLU
N-:1~i7-7?--.J!2!L--wHTI!'ED Al~L __..Jlli__ BAN CONNECTOR 111t
SERIAL DATA
DRIVER SIDE HIGH DRIVER SIDE lOW REDUNDANT INDICATOR IGNffiON 1
..

9J-80 Supplemental Restraint System
DTC36
PASSENGER LOOP ENERGY RESERVE FEED OPEN
CIRCUIT DESCRIPTION
During the "Continuous Monitoring" tests the DERM
monitors the voltage at
"Passenger Source Sense"
terminal "AS". When the circuit is operating normally the
measured voltage
will be slightly less than "Passenger
3S VLR." If the "Passenger 3S VLR" circuit opens the
voltage measured at
"Passenger Source Sense" will
decrease to slightly less than "Ignition 1" voltage. When
the voltage measured at
"Passenger Source Sense" is
within a specified range of "Ignition 1" for 500
milliseconds DTC 3S is set.
DTC WILL SET WHEN
The voltage measured at "Passenger Source Sense"
terminal "AS" is within a specified range of "Ignition 1" for
500 milliseconds. This test is run every 100 milliseconds
during "Continuous Monitoring" tests.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
diagnostic trouble code.
DTC WILL CLEAR WHEN
The voltage measured at "Passenger Source Sense"
terminal "AS" is outside the specified range of "Ignition 1"
which sets the diagnostic trouble code, for 500
milliseconds.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks for an open in the "Passenger 3S
VLR" circuit.
3. This test determines whether the malfunction is due
to high resistance
in the "Passenger Source Sense"
circuit.
4. This test checks for a short from the
"Passenger
Source Sense"
circuit to B+.
5. This test determines whether the malfunction is due
to a malfunction within the dual pole arming sensor.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection at dual pole arming sensor terminal
"1" or "5",
poor connection at DERM terminal "A3" or" AS", an open
in CKT 1813 or CKT 1814 or an open inside the dual pole
arming sensor.
SAS·l
JOINT CONNECTION ,.,. " IGNITION 1
DRIVER 38VLR PASS.38VLR PASS. SOURCE SENSE
PASS SIDE HIGH PASS SIDE LOW
SERIAL DATA
SRS INDICATOR
..

9J·82 Supplemental Restraint System
DTC37
HYBRID INFLATOR LOW PRESSURE
CIRCUIT DESCRIPTION
During normal "Ignition 1" voltage is applied from the
"C-23" fuse trough passenger low peraaaure warning
sensor to DERM st
"LPS" terminal "83". When the
pressure in the gas cylinder within the passenger inflator
module is operating normally the measured voltage will
be the same voltage as "Ignition 1" voltage. If the
passenger
low pressure warning sensor circuit opens or
short to ground the voltage measured st
"LPS" will
decrease to near ground voltage. When the voltage
measured
at"LPS" is outside the specified renge DTC 37
is set.
DTC WILL SET WHEN
The voltage measured at "LPS" terminal "83" is outside
the specified renge. This test is run every 100
milliseconds during "Continuous Montoring" tests.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
diagnostic trouble code.
DTC WILL CLEAR WHEN
The voltage measured at "LPS" terminal "83" is within a
specified rande which doesn't the diagnostic trouble
code, svery
100 milliseconds.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test determines whether the malfunction is due
to high resistance
in the "Passenger Low Pressure
Warning
Sensor."
3. This test checks for an open onside the "LPS" circuit.
4. This test checks for a short from the "LPS" cirsuit to
ground.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection Passenger
Inflator Module terminal "1" or "4"
poor connection at DERM terminal "83", an open in CKT
1834 or CKT 1834 or an open inside the Passenger
Inflator Module.
SRS-1 JOINT CONNECTION 10 , ... IGNITION!
IGNITION 1 ORIVER SOURCE SENSE DRIVER 38VLR PASS.3eVLR PASS. SOURCE SENSE
REDUNDAT INDICATOR GROUND
PASS SIDE HIGH
PASS SIDE LOW
SPARE/I.PS DRIVER SEAT BELT
SERIAL DATA
DRIVER SIDE HIGH DRIVER SIDE LOW REDUNDANT INDICATOR IGNITION!
SRS INDICATOR
..

9J-84 Supplemental Restraint System
DTC42
LOOP ENERGY RESERVE VOLTAGE LOW
CIRCUIT DESCRIPTION
During the "Turn-ON" tests, performed at the beginning
of each ignition
cycle, the DERM delays charging of the
"Driver "36
VLR" terminal "A4" and "Passenger 36 VLR"
terminal
"A3" power supplies. After delay has expired
both "36
VLR" power supplies are allowed to change.
The DERM monitors each
"36 VLR" power supply to
ensure each has changed to a
voltage above a specified
value within 1 0 seconds after "Ignition 1" voltage is first
applied to DERM. When either "36 VLR" power supply
does not reach the specified voltage within the allowed
time or, once reaching the voltage, falls it for 500
milliseconds, DTC 42 is set.
DTC WILL SET WHEN
The voltage at either "36 VLR" power supply does not
exceed a specified
value within 10 seconds after "Ignition
1" voltage is first applied to the DERM or once having
reached the specified
value, either "36 VLR" power
supply voltage falls below the specified value for 500
milliseconds.
This test is run each ignition cycle at
"Turn-ON" to detect a change time failure and, after
charging, tested every
100 milliseconds during the
"Continuous Monitoring" tests.
ACTION TAKEN
DERM turns "on" the "AIR BAG" warning lamp and sets
a diagnostic
trouble code.
DTC WILL CLEAR WHEN
The voltages measured at "Driver 36 VLR" terminal "A4"
and "Passenger 36
VLR" terminal "A3" are above a
specified
value for 500 milliseconds.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks whether the DERM has set the
diagnostic
trouble code falsely.
3. This test checks whether a malfunctioning dual pole
arming sensor is preventing dual pole arming sensor
is preventing the "Driver 36
VLR" or "Passenger 36
VLR" from charging.
4. This test checks for a short from the "Driver 36 VLR"
or "Passenger 36 VLR" circuit to 8+.
5. This test checks for a short from the "Driver 36 VLR"
or "Passenger 36 VLR" circuit to ground.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a short
from "Driver 36
VLR" or "Passenger 36 VLR" to B+ or
ground, or a short inside the
dual pole arming sensor.
SRS~1 JOINT CONNECTION IBOii 12 1G IGNITION 1
DRIVER 36VLR PASS.31VLR PASS. SOURCE SENSE
REDUNDAT INDICATOR GROUND
PASS SIDE HIGH PASS SIDE LOW
SPAREilPS
SERIAL DATA
DRIVER SIDE HIGH DRIVER SIDE LOW REDUNDANT INDICATOR IGNmON 1
1111

9J-86 Supplemental Restraint System
DTC43
DRIVER SOURCE FEED LOW
CIRCUIT DESCRIPTION
During normal, non-deployment operation of the SRS
the DERM monitors the voltage supplied through the
dual pole arming sensor to the high side of the driver
deployment loop at the "Driver Source Sense" terminal
"AS".
This measured voltage will have a value
approximately equal to "Driver 36 VLR." When the
voltage measured at "Driver Side Low" terminal "88" is
in its normal operating range, indicating driver
deployment loop integrity has been maintained, while
simultaneously
the voltage measured at "Driver Source
Sense"
is a specified amount below "Driver 36 VLR" for
SOO milliseconds DTC 43 is set.
DTC WILL SET WHEN
The voltage measured at "Driver Side Low" terminal "88"
is within a specified percentage of "Driver 36 VLR" while
simultaneously
the voltage measured at "Driver Source
Sense" terminal
during the "Continuous Monitoring"
tests.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets
a diagnostic
trouble code.
DTC WILL CLEAR WHE
The voltage measured at "Driver Side Low" terminal "88"
is within a specified percentage of "Driver 36 VLR" while
simultaneously
the voltage measured at "Driver Source
Sense" terminal "AS"
is within a specified amount of
"Driver 36 VLR" for SOO milliseconds.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
2. This test checks for an open in "Driver Source
Sense"
circuit.
3. This test checks for a short from the "Driver Source
Sense"
circuit to ground.
4. This test determines whether the malfunction is due
to increased resistance across the "Driver
Source
Sense"
resistor in the dual pole arming sensor.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection to the DERM at terminal "AS", a poor
connection to the dual pole arming sensor at terminal "6",
an open or short to ground in CKT 1811 or a partial open
inside the
dual pole arming sensor.
SRS-1 FUSE JOINT CONNECTION ___ sR~S~C-~23-10_A __ ~'NK----~·~·~~----------~~-Pw--~•·~~---TO IGNITION SWITCH
FUSE! SRS C-24 10A , ... REO
TO FUSE 1001 ~~~~g~ _S_R_.S C,.:;.:·2:i-2 -10A--~r'f"---....l!!!<'----• 1111
181Z 1113
1814
B RED
IGNITION 1 IGNITION 1
DRIVER 36VLR PASS.38VLR PASS. SOURCE SENSE
REDUNOAT INDICATOR GROUND
PASS SlOE HIGH
PASS SIDE LOW
SERIAL DATA
SRS INDICATOR
..