ISUZU TROOPER 1995 Workshop Manual

Supplemental Restraint System 9J-87
DTC43
DRIVER SOURCE FEED LOW
STEP
ACTION YES NO
1 WAS THE "SRS
DIAGNOSTIC
SYSTEM CHECK'' GOTOSTEP2. GO TO THE "SRS PERFORMED? DIAGNOSTIC
SYSTEM CHECK."
2
WHEN MEASUREMENTS ARE REQUESTED IN THIS CHART GOTOSTEP3. GO TO STEPS.
USE J-39200 DVM WITH CORRECT TERMINAL ADAPTER FROM J-3S616-A. IGNITION SWITCH "OFF."
DISCONNECT DRIVER
AND PASSENGER INFLATOR
MODULES, YELLOW 2-WAY OR 4--WAY CONNECTORS
LOCATED AT THE TOP OF THE STEERING COLUMN AND BEHIND THE 1/P COMPONENT DOOR ASSEMBLY.
DISCONNECT DERM. CHECK FOR
PROPER CONNECTION TO DERM AT TERMINAL "AS".
IF OK THEN DISCONNECT DUAL POLE ARMING SENSOR.
CHECK FOR PROPER CONNECTION TO DUAL POLE
ARMING SENSOR
AT TERMINAL "6".
IF OK, THEN MEASURE RESISTANCE FROM DUAL POLE
ARMING SENSOR HARNESS CONNECTOR TERMINAL "6"TO
DERM HARNESS CONNECTOR TERMINAL "AS". IS RESISTANCE S.On OR LESS?
3 MEASURE RESISTANCE ON DERM HARNESS CONNECTOR GOTOSTEP4. GO TO STEPS.
FROM TERMINAL "AS" TO TERMINAL "A1"(GROUND). DOES
J39200 DISPLAY "OL"{INFINITE)?
4 MEASURE RESISTANCE ON DUAL POLE ARMING SENSOR GOTOSTEP6. GO TO CHART A. CONNECTOR FROM TERMINAL "2" TO TERMINAL "6".
IS RESISTANCE 12.9Kn OR MORE?
s REPLACE SRS HARNESS. GOTOSTEP7.
6 REPLACE SRS DUAL POLE ARMING SENSOR. GOTOSTEP7.
7 REPLACE DUAL POLE ARMING SENSOR. GO TO THE "SRS DIAGNOSTIC SYSTEM
RECONNECT ALL SRS COMPONENTS, ENSURE ALL CHECK".
COMPONENTS ARE PROPERLY MOUNTED.
CLEAR SRS DIAGNOSTIC TROUBLE CODES. REPEAT "SRS DIAGNOSTIC SYSTEM CHECK."

9J-88 Supplemental Restraint System
DTC44
PASSENGER 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 ofthe passenger
deployment
loop at the "Passenger Source Sense"
terminal
"AS". This measured voltage will have a value
approximately equal to "Passenger 3S VLR." When the
voltage measured at "Passenger Side Low" terminal "87"
is in its normal operating range, indicating passenger
deployment
loop integrity has been maintained, while
simultaneously
the voltage measured at "Passenger
Source Sense" is a specified amount below "Passenger
3S VLR" for 500 milliseconds DTC 44 is set.
DTC WILL SET WHEN
The voltage measured at "Passenger Side Low" terminal
"87"
is within a specified percentage of "Passenger 3S
VLR" while simultaneously the voltage measured at
"Passenger Source Sense" terminal "AS" is within a
specified amount
below "Passenger 3S VLR" 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.
TO IGNITION SWITCH
FUSEj SRS C·24
10A , ... D
FUSE SRS C·23 10A 1001
DTC WILL CLEAR WHEN
The voltage measured at "Passenger Side Low" terminal
"87"
is within a specified percentage of "Passenger 3S
VLR" while simultaneously the voltage measured at
"Passenger Source Sense" terminal "AS" is within a
specified amount of "Passenger 3S VLR" 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 "Passenger Source
Sense" circuit.
3. This test checks for a short from the "Passenger
Source Sense" circuit to ground.
4. This test determines whether the malfunction is due
to increased resistance across the
"Passenger
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 "1",
an open or short to ground in CKT 1814 or a partial open
inside the
dual pole arming sensor.
SRS-1 JOINT CONNECTION ~ IGNITION1
DRIVER 36VLR PASS. l&VLR PASS. SOURCE SENSE
PASS SIDE HIGH PASS SIDE LOW
1---""--:t--':1--7-7---7---""103"-4 --BLKIBLU 1--""--7-------:7-7--7--'TO ~fc~E-LT_,.,_BLU
~~~~~7----~11~~---W~fflE .J~L -----llli-BRN CONNECTOR 1811 11!120
..

Supplemental Restraint System 9J-89
DTC44
PASSENGER SOURCE FEED LOW
STEP
ACTION YES NO
1 WAS THE "SRS DIAGNOSTIC
SYSTEM CHECK" GOTO STEP2. GO
TO THE "SRS
PERFORMED? DIAGNOSTIC
SYSTEM CHECK."
2
WHEN MEASUREMENTS ARE REQUESTED IN THIS CHART GOTO STEP3. GOTOSTEP5.
USE J-39200 DVM WITH CORRECT TERMINAL ADAPTER FROM J-35616-A.
IGNITION SWITCH "OFF."
DISCONNECT DRIVER AND PASSENGER INFLATOR
MODULES, YELLOW 2-WAY OR 4-WAY CONNECTORS
LOCATED AT THE TOP OF THE STEERING COLUMN AND
BEHIND THE 1/P COMPONENT DOOR ASSEMBLY.
DISCONNECT DERM. CHECK FOR PROPER CONNECTION TO DERM AT TERMINAL "A6".
IF OK THEN DISCONNECT DUAL POLE ARMING SENSOR.
CHECK FOR PROPER CONNECTION TO DUAL POLE
ARMING SENSOR AT TERMINAL "1".
IF OK, THEN MEASURE RESISTANCE FROM DUAL POLE
ARMING SENSOR HARNESS CONNECTOR TERMINAL "1 "TO DERM HARNESS CONNECTOR TERMINAL "A6".
IS RESISTANCE S.On OR LESS?
3 MEASURE RESISTANCE ON DERM HARNESS CONNECTOR GOTOSTEP4. GOTOSTEP5.
FROM TERMINAL "A6" TO TERMINAL "A1"(GROUND). DOES J-39200 DISPLAY "OL"(INFINITE)?
4 MEASURE RESISTANCE ON DUAL POLE ARMING SENSOR GOTOSTEP6. GO TO CHART A.
CONNECTOR FROM TERMINAL "1" TO TERMINAL "7". IS RESISTANCE 12.9Kn OR MORE?
5 REPLACE SRS
HARNESS. GOTOSTEP7.
6 REPLACE
DUAL POLE ARMING SENSOR. GOTOSTEP7.
7 RECONNECT ALL SRS COMPONENTS, ENSURE ALL GO TO THE "SRS DIAGNOSTIC SYSTEM
COMPONENTS
ARE PROPERLY MOUNTED. CHECK''. CLEAR SRS DIAGNOSTIC TROUBLE CODES. REPEAT THE "SRS DIAGNOSTIC SYSTEM CHECK."

9J-90 Supplemental Restraint System
DTC51
FRONTAL
CRASH DETECTED
CIRCUIT DESCRIPTION
Closure of the dual pole arming sensor is detected when
the voltage measured at "Driver
Side High" terminal "89"
or at "Passenger Side High" terminal "A7" is within a
specified
amount of its respective deployment loop
supply voltage.
Closure of either discriminating sensor is
detected when the voltage measured at "Driver
Side
High" terminal "88" or at "Passenger Side High" terminal
"87" is within a specified amount of ground potential.
When both conditions are met simultaneously
on either
driver side
or passenger side for not less than 250
milliseconds "Crash Data" is recorded and DTC 51 is set.
DTC WILL SET WHEN
Closure of the dual pole arming sensor and at least one
discriminating sensors is detected for not less than
250
microseconds on either the driver side or passenger
side. Conditions are monitored whenever the DERM is
functioning
normally.
ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp, records
"Crash
Data," and sets a diagnostic trouble code.
TO IGNITION SWITCH
FUSE! SRS C-24 10A 1101 R D
DTC WILL CLEAR WHEN
A scan tool "Clear Codes" command is received by the
DERM.
DTC CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic chart.
3. If inflator module(s) has not deployed, DTC 51 may
have set falsely.
4. If DTC 51 has set with no signs of frontal impact, the
diagnostic trouble code has set falsely.
5. This test checks for a DERM malfunction setting the
diagnostic trouble code.
6. This test checks for a DERM malfunction setting the
diagnostic trouble code.
7. This test determines whether the diagnostic trouble
code was set inadvertently during diagnosis.
8. When a frontal crash has occurred, it is necessary to
perform the indicated procedures to ensure the
SIR
system is fully functional.
IGNITION 1
DRIVER 36VLR PASS.3SVLR PASS. SOURCE SENSE
PASS SIDE HIGH
PASS SIDE LCIW
SERIAL DATA
SAS INDICATOR

Supplemental, Restraint System 9J-91
DTC51
FRONTAL CRASH DETECTED
STEP
ACTION YES NO
1 WAS THE "SRS
DIAGNOSTIC
SYSTEM CHECK" GOTOSTEP2. GO TO THE "SRS
PERFORMED? DIAGNOSTIC
SYSTEM CHECK."
2 IS DTC 51 CURRENT? GOTOSTEP3. GO TO THE "SRS
DIAGNOSTIC
SYSTEM CHECK".
3 IGNITION SWITCH "OFF." GOTOSTEP8. GOTOSTEP4.
HAS INFLATOR MODULE(S) DEPLOYED?
4
INSPECT FRONT OF VEHICLE AND UNDERCARRIAGE FOR GOTO STEPS. GOTO STEP5.
SIGNS OF IMPACT.
5 IGNITION SWITCH "ON."
IGNITION SWITCH GOTOSTEP6.
USING TECH 1 DATA LIST FUNCTION SELECT "DEPLOY
"OFF."
COMMAND." GO TO CHART A. IS DEPLOY COMMAND "ACTIVE"?
6 CLEAR SRS DIAGNOSTIC TROUBLE CODES. IGNITION SWITCH GOTOSTEP7. IS DTC 51 SET?
"OFF."
GO TO
CHART A.
7 IGNITION SWITCH "OFF."
GO TO CHART A. REPEAT THE "SRS
WAS
DTC 51 SET WHEN THE "SRS DIAGNOSTIC SYSTEM DIAGNOSTIC
CHECK"WAS FIRST PERFORMED? SYSTEM CHECK."
8
REPLACE COMPONENTS AND PERFORM INSPECTIONS AS GO TO THE "SRS DIAGNOSTIC SYSTEM
DIRECTED IN "REPAIRS AND INSPECTIONS REQUIRED
CHECK". AFTER AN ACCIDENT' IN THIS SECTION.
CLEAR SRS DIAGNOSTIC TROUBLE CORES. REPEAT THE "SRS DIAGNOSTIC SYSTEM CHECK."

9J-92 Supplemental Restraint System
DTC52
CIRCUIT DESCRIPTION
DATA AREA FULL
ACTION TAKEN
When there is a frontal crash of sufficient force to activate
the dual pole arming sensor and at least one of the two
discriminating sensors simultaneously,
DTC 51 is set. At
this time the DERM
will record information regarding SIR
system status and vehicle status in EEPROM. DTC 52
will set when the DERM has stored information regarding
eight frontal crash events.
DTC WILL SET WHEN
The DERM attempts to store frontal crash information
and finds the
EEPROM data area full. This test is run
each time the DERM stores or attempts to store
information regarding a frontal crash event. DERM
turns
"ON" the "AIR BAG" warning lamp and sets
a diagnostic trouble code.
DTC WILL CLEAR WHEN
A scan tool "Clear Codes" command is received by the
DERM.
If, at the next ignition "ON" after receiving a
"Clear Codes" command, the DERM detects the data
area is
full, a history diagnostic trouble code is set. This
allows the "AIR BAG" warming lamp to illuminate should
any additional malfunctions be detected.
SRS·1 FUSE JOINT CONNECTION TO IGNITION SWITCH
FUSE! SRS C·2' 10A 1101 R D
--~SR~S~C~·23~1~0A~-IPNK----~~~~~------------_sn~~»~~~~·~~---l IGJ;~ON __ __.:FU:;:Si-E ____ _.fr;:--___ 1!!!107!!...-___ SWITCH SAS C·22 1 OA
FUSE STARTER 1801
Al~L • 1127 CONNECTOR 1111
1!120
IGNITION1
IGNITION1
DRIVER SOURCE SENSE DRIVER 36VLR PASS. 3SVLR PASS. SOURCE SENSE
REDUNDAT INDICATOR
GROUND
PASS SIDE HIGH
PASS SIDE LOW
SPARQPS DRIVER SEAT BELT
CRANK
SERIAL
DATA
DRIVER SIDE HIGH DRIVER SIDE LOW REDUNDANT INDICATOR
IGNITION 1
SRS INDICATOR
•

STEP
1 WAS THE ·sRS PERFORMED?
~-
Supplemental Restraint System 9J-93
DTC52
DATA AREA FULL
ACTION YES
DIAGNOSTIC SYSTEM CHECK" REPLACE
DERM.
REPEAT THE "SRS
DIAGNOSTIC
SYSTEM CHECK." NO
GO
TO THE "SRS
DIAGNOSTIC SYSTEM CHECK."

9J-94 Supplemental Restraint System
DTC53
DRIVER SIDE LOW HIGH RESISTANCE
CIRCUIT DESCRIPTION
During the "Initiator Assembly Resistance Test" the
DERM grounds the "Driver Side
Low" terminal "B8" and
turns "ON" the passenger current source at the
"Passenger Side High" terminal "A7". This causes a
known amount of current to
flow through the passenger
initiator circuit
allowing this resistance to be calculated.
The normal, non-deployment current flow through the
driver
deployment loop is also affected since the DERM
is
supplying ground through a resistor bypassing the
ground
supplied by the resistance of the discriminating
sensor network. When the
voltage difference between
"Driver Side High" terminal "B9" and "Driver Side Low"
terminal "B8" is above a specified value DTC 53 is set.
DTC WILL SET WHEN
The voltage difference between "Driver Side High"
terminal "B9" Driver Side Low" terminal "B8" is above a
specified
value. This test

is run once each ignition
cycle
during the "Initiator Assembly Resistance Test" when: 1)
No "higher priority
faults" are detected during "Turn-O.N,"
2) No "higher priority faults" are detected dunng
"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 determines whether the malfunction is due
to a high resistance or open
in the "Driver Side Low"
circuit between the DERM and the Steering
column
harness connector.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection at DERM
terminal "B8" or an open in CKT
IB20.
The test for this diagnostic trouble code is run only
while
the "AIR BAG" warning lamp is performing the bulb
check. When a scan tool "Clear Codes" command is
issued and the
malfunction is still present, the dtc will not
reappear
until the next ignition cycle.
iYOS BLK/RE
.rBODY t824 VLT IB21J
DRIVER 36VLR PASS. 38VLR PASS. SOURCE SENSE
PASS SIDE HIGH
PASS SIDE LOW
l---....!E:L_-+--4+j-+-___..!!IB3~4--BLK/BLU
~-'!W.-4---4-~----'TO ~iJELT '"*' BLU
SERIAL DATA
DRIVER SIDE HIGH DRIVER SIDE LOW REDUNDANT INDICATOR IGNITION 1
SRS INDICATOR

Supplemental Restraint System 9J-95
DTC53
DRIVER SIDE LOW HIGH RESISTANCE
STEP
ACTION YES
NO
1 WAS THE "SRS
DIAGNOSTIC SYSTEM CHECK" GOTOSTEP2. GO TO THE "SRS PERFORMED? DIAGNOSTIC
SYSTEM CHECK."
2
WHEN MEASUREMENTS ARE REQUESTED IN THIS CHART GO TO CHART A. GOTOSTEP3.
USE J-39200 DVM WITH CORRECT TERMINAL ADAPTER FROM J-35616-A. IGNITION SWITCH "OFF."
DISCONNECT DRIVER
AND PASSENGER INFLATOR
MODULES, YELLOW 2-WAY OR 4-WAY CONNECTORS
LOCATED AT THE TOP OF THE STEERING COLUMN AND
BEHIND THE 1/P COMPARTMENT DOOR ASSEMBLY.
DISCONNECT DERM.
CHECK FOR PROPER CONNECTION TO DERM AT TERMINAL "BB"
IF OK THEN MEASURE RESISTANCE FROM DERM HARNESS
CONNECTOR TERMINAL "BS• TO STEERING COLUMN
HARNESS CONNECTOR TERMINAL "1".
IS RESISTANCE
S.On OR LESS?
3 REPLACE SRS HARNESS. GO TO THE "SRS DIAGNOSTIC SYSTEM
RECONNECT
ALL SRS COMPONENTS, ENSURE ALL CHECK".
COMPONENTS ARE PROPERLY MOUNTED.
CLEAR SRS DIAGNOSTIC TROUBLE CODES.
REPEAT THE "SRS" DIAGNOSTIC SYSTEM CHECK."

9J-96 Supplemental Restraint System
DTC54
PASSENGER SIDE LOW HIGH RESISTA E
CIRCUIT DESCRIPTION
During the "Initiator Assembly Resistance Test" the
DERM grounds the "Passenger Side Low"
terminal "B7''
and turns
"ON" the driver current source at the "Driver
Side High" terminal "B9". this causes a known amount of
current to
flow through the driver initiator circuit allowing
the resistance to be calculated. The normal,
non-deployment current flow through the passenger
deployment loop is also affected since the DERM is
supplying ground through a resistor bypassing the
ground
supplied by the resistance of the discriminating
sensor network. When the
voltage difference between
"Passenger Side
High" terminal "A7" and "Passenger
Side Low''
terminal "B7" is above a specified value DTC
54 is set.
DTC WILL SET WHEN
The voltage difference between "Passenger Side High"
terminal "A7"
and "Passenger Side Low" terminal "B7" is
above a specified
value. This test is run once each
ignition
cycle during the "Initiator Assembly Resistance
Test" 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)"1gnition 1" 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 determines whether the malfunction is due
to a high resistance or open in the "Passenger Side
Low" circuit between the DERM and the passenger
inflator module harness connector.
DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor
connection at DERM
terminal "B7" or an open in CKT.
The test for this diagnostic trouble code is run only while
the "AIR BAG" warning lamp is performing the bulb
check. When a scan tool "Clear Codes" command is
issued and the
malfunction is still present, the DTC will ~
not reappear until the next ignition cycle.
SRS-1 JOINT CONNECTION 1105 1 10 TO FUSE IGNITION SWITCH SRS C-22 10A
PASS SIDE HIGH
PASS SIDE LOW
SERIAL
DATA
SRS INDICA TOR
•