ISUZU TF SERIES 2004 Manual Online
Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 81 of 4264
RESTRAINT CONTROL 9A1-11
3.
When all circuitry outside the SRS control unit has
been found to operate properly, as indicated by the
appropriate diagnostic chart, then and only then
should the SRS control unit be replaced.
Chart A SRS control unit Integrity Check
WARNING: DURING SERVICE PROCEDURES. BE VERY CAREFUL WHEN HANDLING A SRS CONTROL
UNIT. NEVER STRIKE OR JAR THE SRS CONTROL UNIT. NEVER POWER UP THE SRS WHEN THE SRS
CONTROL UNIT IS NOT RIGIDLY ATTACHED TO THE VEHICLE. ALL SRS CONTROL UNIT AND MOUNTING
BRACKET FASTENERS MUST BE CAREFULLY TORQUED AND THE ARROW MUST BE POINTING TOWARD
THE FRONT OF THE VEHICLE TO ENSURE PROPER OPERATION OF THE SRS. THE SRS CONTROL UNIT
COULD BE ACTIVATED WHEN POWERED WHILE NOT RIGIDLY ATTACHED TO THE VEHICLE WHICH COULD
CAUSE DEPLOYMENT AND RESULT IN PERSONAL INJURY
Step Action Yes No
1
1. This chart assumes that the “SRS Diagnostic System
Check” and either a symptom chart or a diagnostic trouble
code chart diagnosis have been performed. When all
circuitry outside the SRS control unit has been found to
operate properly, as indicated by the appropriate diagnostic
chart, and the symptom or DTC remains current, the
following
2. Diagnostic procedures must be performed to verify the need
for SRS control unit replacement.
3. Ignition switch “OFF”.
4. Reconnect all SRS components, ensure all components are
properly mounted.
5. Ensure the ignition switch has been “OFF” for at least 15
seconds.
6. Note “AIR BAG” warning lamp as ignition switch is turned
“ON.”
Does warning lamp flash 7 times then go “OFF”? The symptom or
DTC is no longer
occurring.
Clear SRS
diagnostic trouble
codes.
Repeat “SRS
Diagnostic System
Check” Go to Step 2
2 Using a scan tool request diagnostic trouble code display.
Is the same symptom or DTC occurring as was when the “SRS
Diagnostic System Check” was first performed? Go to Step 3 Ignition switch
“OFF”.
Go to the
appropriate chart for
the indicated
malfunction.
3
1. Clear “SRS Diagnostic Trouble Codes”.
2. Ignition switch “OFF” for at least two minutes.
3. Note “AIR BAG” warning lamp as ignition switch is turned
“ON.”
Does warning lamp flash 7 times then go “OFF”? SRS is functional
and free of
malfunctions.
No further diagnosis
is required.
Go to Step 4 Ignition switch
“OFF”.
Replace SRS control
unit.
Go to Step 4
4 Reconnect all SRS components, ensure all components are
properly mounted.
Was this step finished? Repeat the “SRS
Diagnostic System
Check” Go to Step 4
Page 82 of 4264
9A1-12 RESTRAINT CONTROL SYSTEM
Chart B “AIR BAG” Warning Lamp Comes “ON” Steady
RTW49JLF000101
Circuit Description
When the ignition switch is first turned “ON”, “Ignition 1”
voltage is applied from the “METER” fuse to “AIR
BAG”, warning lamp which is connected to “SRS
Warning Lamp”, terminal “39”. The “SRS” fuses appl
y
system voltage to the “Ignition 1” inputs, terminals “35”.
The SRS control unit responds by flashing the “AIR
BAG” warning lamp 7 times. If “Ignition 1” is less than
9 volts, the “AIR BAG” 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 SRS waring lamp circuit.
Page 83 of 4264
RESTRAINT CONTROL 9A1-13
Chart B “AIR BAG” warning lamp comes “ON” Steady
Step Action Yes No
1
1. When measurements are requested in this chart use 5-8840-
0285-0 DVM with correct terminal adapter from 5-8840-
0385-0.
2. Ignition switch “OFF.”
3. Connect scan tool to data link connector, follow directions as
given in the scan tool instruction MANUAL.
4. Ignition switch “ON.”
5. Request SRS diagnostic trouble code display.
Dose scan tool indicate “No Data Received”? Go to Step 2 Go to Step 3
2
1. Ignition switch “OFF”.
2. Inspect SRS control unit harness connector connection to
SRS control unit.
Is it securely connected to the SRS control unit? Ignition switch
“OFF.”
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 SRS data list.
Is “ignition” more than 9 volts? Go to Step 4 Ignition switch
“OFF.”
Replace SRS
control unit.
Go to Step 5
4
1. Ignition switch “OFF.”
2. Disconnect SRS coil and passenger air bag assemblies.
yellow connector located at base of steering column and
behind the glove box assembly.
Disconnect SRS control unit.
3. Disconnect the connector of “SRS Warning Lamp” of
instrument cluster.
4. Measure resistance from SRS control unit harness connector
terminal “40” to ground.
Does 5-8840-0285-0 DVM display “OL” (Infinite)? Go to Chart A Replace SRS
harness.
Go to Step 5
5 Reconnect all SRS components, ensure all components are
properly mounted.
Was this step finished? Repeat the “SRS
Diagnostic System
Check” Go to Step 5
Page 84 of 4264
9A1-14 RESTRAINT CONTROL SYSTEM
Chart C “AIR BAG” Warning Lamp Does Not Come “ON” Steady
RTW49JLF000101
Circuit Description
When the ignition switch is first turned “ON”, “Ignition 1”
voltage is applied from the “METER” fuse to the “AIR
BAG” warning lamp which is connected to “SRS
Warning Lamp”, terminal “39”. The “SRS” fuse appl
y
system voltage to the “Ignition 1” inputs, terminals “35”.
The SRS control unit responds by flashing the “AIR
BAG” warning lamp seven times. If “Ignition 1” is more
than 16 volts, the “AIR BAG” warning lamp will be still
“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 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.
Page 85 of 4264
RESTRAINT CONTROL 9A1-15
Chart C “AIR BAG” Warning Lamp Does Not Come “ON” Steady
Step Action Yes No
1
1. When measurements are requested in this chart, use 5-8840-
0285-0 DVM with correct terminal adapter from 5-8840-
0385-0.
2. Ignition switch “OFF.”
3. Remove and inspect “METER” fuse to the “AIR BAG”
warning lamp.
Is fuse good? Go to Step 2 Go to Step 7
2
1. Ignition switch “OFF.”
2. Disconnect SRS coil and passenger air bag assemblies.
Yellow connector located at base of steering column and
behind the glove box assembly.
3. Disconnect SRS control unit.
4. Ignition switch “ON.”
5. Measure voltage on SRS control unit harness connector from
terminal “39” to terminal “40” (ground).
Is system voltage present on terminal “39”? Go to Step 4 Go to Step 3
3
1. Ignition switch “OFF.”
2. Remove instrument meter cluster.
3. Check for proper connection to instrument cluster at SRS
warning lamp circuit terminal.
4. If ok, then remove and inspect “AIR BAG” bulb.
Is bulb good? Go to Step 5 Replace bulb.
Go to Step 6
4
1. Ignition switch “OFF.”
2. Disconnect instrument meter cluster harness connector.
3. Ignition switch “ON.”
4. Measure voltage on SRS control unit harness connector from
terminal “39” to terminal “40” (ground).
Is voltage 1 volt or less? Go to Chart A Replace SRS
harness.
Go to Step 6
5
1. Install bulb.
2. Measure resistance from instrument meter cluster harness
connector SRS warning lamp circuit terminal to SRS control
unit harness connector terminal “7”.
Is 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, ensure all components are
properly mounted.
Was this step finished? Repeat the “SRS
Diagnostic System
Check” Go to Step 6
7 Perform chart C.
Was this step finished? Go to Step 8 Go to Step 1
8
1. Replace “METER” fuse.
2. Ignition switch “ON” wait 10 Seconds then ignition switch “Off.
“
3. Remove and inspect “METER” fuse.
Is fuse good? Install “METER”
fuse.
Go to Step 10 Go to Step 9
Page 86 of 4264
9A1-16 RESTRAINT CONTROL SYSTEM
Step Action Yes No
9
1. Disconnect SRS coil and passenger air bag assemblies.
Yellow connectors located at base of steering column and
behind the glove box assembly.
2. Disconnect SRS control unit.
3. Replace “METER” fuse.
4. Ignition switch “ON” wait 10 seconds.
5. Ignition switch “OFF”.
6. Remove and inspection “METER” fuse.
Is fuse good? Install “METER”
fuse.
Go to Chart A Replace SRS
harness.
Replace “METER”
fuse.
Go to Step 10
10 Reconnect all SRS components, ensure all components are
properly mounted.
Was this step finished? Repeat the “SRS
Diagnostic System
Check” Go to Step 10
Page 87 of 4264
RESTRAINT CONTROL 9A1-17
DTC B0016 (Flash Code 16) Passenger Airbag Squib Circuit Low Resistance
RTW49JLF000101
Circuit Description
When the ignition switch is turned “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”.
“Passenger Bag Low” terminal “47” is grounded through
a resistor and the passenger current source connected
to “Passenger Bag High” terminal “48” allows a known
amount of current to flow. By monitoring the voltage
difference between “Passenger Bag High” and
“Passenger Bag Low”, the SRS control unit calculates
the combined resistance of 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 “Passsenger Bag
High” and “Passenger Bag Low”, and connector
terminal contact is above a specified value. This test
is run once 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
SRS control unit turns “ON” the “AIR BAG” warning
lamp and sets a diagnostic trouble code.
Page 88 of 4264
9A1-18 RESTRAINT CONTROL SYSTEM
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 in
the SRS control unit.
3.
This test verifies connection of the yellow connector.
4.
This test cheeks for proper operation of the shorting
clip in the yellow 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 circuits “Passenger Bag High” and “Passenger
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 “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.
DTC B0016 (Flash Code 16) Passenger Airbag Squib Circuit Low Resistance
Step Action Yes No
1 Was 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 the problem found, repair as necessary.
Was a problem found? Verify repair Go to Step 3
3
1. Ignition switch “Off.”
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 “ON.”
Is DTC B0016 Current? Go to Step 5 Go to Step 7
5
1. Ignition switch “Off.”
2. Disconnect 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 SRS coil and passenger air bag
assembly harness connectors.
4. Ignition switch “ON.”
Is DTC B0016 current? Go to Step 6 Ignition switch
“Off.”
Replace the
passenger air bag
assembly.
Go to Step 7
6
1. Ignition switch “Off.”
2. There has been a decrease in the total circuit resistance of
the passenger inflator deployment loop
Replace SRS
harness.
Go to Step 7 Go to Chart A
Page 89 of 4264
RESTRAINT CONTROL 9A1-19
Step Action Yes No
the passenger inflator deployment loop.
3. Use the high resolution ohmmeter mode of the DVM while
checking circuits “Passenger Bag High” and “Passenger Bag
Low”, and SRS control unit connector terminal “48” and “47”
to locate the root cause.
Was a fault found?
7
1. Reconnect all components, ensure all component are
properly mounted.
2. Clear diagnostic trouble codes.
Was this step finished? Repeat the “SRS
Diagnostic System
Check” Go to Step 7
Page 90 of 4264
9A1-20 RESTRAINT CONTROL SYSTEM
DTC B0017 (Flash Code 17) Passenger Airbag Squib Circuit High Resistance
RTW49JLF000101
Circuit Description
When the ignition switch is turned “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”.
“Passenger Bag Low” terminal “47” is grounded through
a resister and the passenger current source connected
to “Passenger Bag High” terminal “48” allows a known
amount of current to flow. By monitoring the voltage
difference between “Passenger Bag High” and
“Passenger Bag Low” the SRS control unit calculates
the combined resistance of 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 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
SRS control unit turns “ON” the “AIR BAG” warning
lamp and sets a diagnostic trouble code.