Isuzu Trooper (1998-2002 year). Manual - part 1098

9J1–29

RESTRAINT CONTROL SYSTEM

DTC 24  Driver Deployment Loop Short To Ground

D09RW014

Circuit Description:

When the ignition switch is turned “ON”, the SDM 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 SDM monitors the voltage at “Driver Bag Low”
terminal “4” and “passenger Bag Low” terminal “16” to
detect shorts to ground in the air bag assembly circuits.

DTC Will Set When:

Neither of the two air bag assemblies is open.
“Ignition 1” is within the normal operating voltage range.
This test is run once each ignition cycle and “Continuous
Monitoring”.  Once these conditions are met and the
voltage at “Driver Bag Low” is below a specified value,
DTC 24 will set.

Action Taken:

SDM turns “ON” the “AIR BAG” warning lamp and sets a
diagnostic trouble code.

DTC Will Clear When:

The malfunction is no longer occurring and the ignition 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 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.

RESTRAINT CONTROL SYSTEM

9J1–30

DTC 24 Driver Deployment Loop Short To Ground 

Step

Action

Yes

No

1

Was the “SRS Diagnostic System Check” performed?

Go to Step 2

Go to the “SRS

Diagnostic

System Check”

2

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 data link connector.  follow directions as

given in the scan tool operator’s manual.

4. Ignition switch “ON.”
5. Read driver bag sense LO.

Is driver bag sense LO less than 1.5 volts?

Go to Step 3

Go to Chart A

3

1. Ignition switch “OFF.”
2. Disconnect SRS coil assembly yellow 2–pin connector located

at base of the steering column. leave passenger air bag
assembly connected.

3. Connect SRS driver / passenger load tool 5–8840–2421–0

and appropriate adapter to SRS coil assembly harness
connector.

4. ignition switch “ON.”

Is DTC 24 current?

Go to Step 4

Go to Step 6

4

1. Ignition switch “OFF.”
2. Disconnect SDM.
3. Disconnect SRS driver / passenger load tool.
4. Measure resistance on SDM harness connector “3” to terminal

“6” (ground).

Does 5–8840–0285–0 display “OL” (infinite)?

Go to Step 5

Replace SRS

harness

Go to Step 7

5

Measure resistance on SDM harness connector from terminal “4”
to terminal “6” (ground).

Does 5–8840–0285–0 display “OL” (infinite)?

Go to Chart A

Replace SRS

harness

Go to Step 7

6

1. Ignition switch “OFF.”
2. Disconnect SRS driver / passenger load tool 5–8840–2421–0

from SRS coil assembly harness connector.

3. Connect SRS driver / passenger load tool 5–8840–2421–0

and appropriate adapter 5–8840–0385–0 to driver air bag
assembly harness connector. located top of the steering
column 2–pin connector.

4. Reconnect SRS coil assembly harness connector as the base

of steering column.

5. Ignition switch “ON.”

Is DTC 24 current?

Ignition switch

“OFF”

Replace SRS coil

assembly

Go to Step 7

Ignition switch

“OFF”

Replace driver air

bag assembly

Go to Step 7

7

1. Reconnect all components ensure all component are properly

mounted.

2. Clear diagnostic trouble codes.

Was this step finished?

Go to the “SRS

Diagnostic

System Check”

Go to Step 7

9J1–31

RESTRAINT CONTROL SYSTEM

DTC 25  Driver Deployment Loop Short To B+

D09RW014

Circuit Description:

When the ignition switch is turned “ON”, the SDM 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 SDM monitors the voltage at “Driver Bag Low”
terminal “4” and “Passenger Bag Low” terminal “16” to
detect shorts to B+ in the air bag assembly circuits.

DTC Will Set When:

“Ignition 1” is in the normal operating voltage range.  This
test is run once each ignition cycle and “Continuous
monitoring”.  Once these conditions are met and the
voltage at “Driver Bag Low” is above a specified value,
DTC 25 will set.

Action Taken:

SDM turns “ON” the “AIR BAG” 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.

RESTRAINT CONTROL SYSTEM

9J1–32

DTC 25 Driver Deployment Loop Short To B+ 

CAUTION: When DTC 25 has been set, it is necessary to replace the SDM.  Setting DTC 25 will also cause DTC
71 to set.  When a scan tool “CLEAR CODES” command is issued and the malfunction is no longer present,
DTC 71 will remain current.  Ensure that the short to B+ condition is repaired prior to installing a replacement
SDM to avoid damaging the SDM.

Step

Action

Yes

No

1

Was the “SRS Diagnostic System Check” performed?

Go to Step 2

Go to the “SRS

Diagnostic

System Check” 

2

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 data link connector. follow directions as

given in the scan tool operator’s manual.

4. Ignition switch “ON.”
5. Read driver bag sense LO .

Is driver bag sense LO more than 3.5 volts?

Go to Step 3

Go to Chart A

3

1. Ignition switch “OFF.”
2. Disconnect SRS coil assembly yellow 2–pin connector at the

base of the steering column. Leave passenger air bag
assembly connected.

3. Connect SRS driver /passenger load tool 5–8840–2421–0 and

appropriate adapter to SRS coil assembly harness connector.

4. Ignition switch “ON.”

Is driver bag sense LO more than 3.5 volts?

Go to Step 4

Go to Step 6

4

1. Ignition switch “OFF.”
2. Disconnect SDM.
3. Disconnect SRS driver /passenger load tool.
4. Measure resistance on SDM harness connector “3” to terminal

“12” (ignition).

Does 5–8840–0285–0 display “OL” (infinite)?

Go to Step 5

Replace SRS

harness

Go to Step 7

5

Measure resistance on SDM harness connector from terminal “4”
to terminal “12” (ignition).

Does 5–8840–0285–0 display “OL” (infinite)?

Go to Chart A

Replace SRS

harness

Go to Step 7

6

1. Ignition switch “OFF”
2. Connect SRS driver / passenger load tool 5–8840–2421–0

and appropriate adapter 5–8840–0385–0 to driver air bag
assembly harness 2-pin connector located at top of the
steering column.

3. Reconnect SRS coil assembly harness  connector as the base

of steering column.

4. Ignition switch “ON.”

Is driver bag sense LO more than 3.5 volts?

Ignition switch

“OFF”

Replace SRS coil

assembly

Go to Step 7

Ignition switch

“OFF”

Replace driver air

bag assembly

Go to Step 7

7

1. Reconnect all components, ensure all component are properly

mounted.

2. Ignition switch “ON.”

Is driver bag senslo less than 3.5 volts?

Ignition switch

“OFF”

Replace SDM

Go to Step 8

Go to Chart A

8

1. Reconnect all components ensure all component are properly

mounted.

2. Clear diagnostic trouble codes.

Was this step finished?

Go to the “SRS

Diagnostic

System Check” 

Go to Step 8