Isuzu Rodeo UE. Manual - part 646

9J1–21

RESTRAINT CONTROL SYSTEM

DTC 18  Passenger Deployment Loop Short To Ground

D09RW002

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 voltages at “Driver Bag Low”
terminal “4” and “Passenger Bag Low” terminal “16” to
detect short 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.
Once these conditions are met and the voltage at
“Passenger Bag Low” is below a specified value, DTC 18
will set.  This test is run once each ignition cycle and
“Continuous Monitoring”.

Action Taken:

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

DTC Will Clear When:

This malfunction is no longer occurring and the ignition
switch is turned “OFF”.

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 compartment.

4. This test determines whether the malfunction is in

CKT IB07–YEL/GRN.

RESTRAINT CONTROL SYSTEM

9J1–22

5. This test determines whether the malfunction is in

CKT 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 CKTs 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.

DTC 18 Passenger 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 J–39200

DVM with correct terminal adapter from J–35616–A.

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 passenger sense LO.

Is passenger sense LO less than 1.5 volts?

Go to Step 3

Go to Chart A.

3

1. Ignition switch “OFF.”
2. Disconnect passenger air bag assembly yellow 2–pin

connector behind the glove box assembly..

3. Leave driver air bag assembly connected.

Connect SRS driver / passenger load tool J–41433 and
appropriate adapter to passenger air bag assembly harness
connector.

4. Ignition switch “ON.”

Is DTC 18 current?

Go to Step 4

Ignition switch

“OFF.”

Replace

passenger air

bag assembly.

Go to Step 6

4

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

“15” to terminal “6” (ground).

Does J–39200 display “0L” (infinite)?

Go to Step 5

Replace SRS

harness.

Go to Step 6

5

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

Does J–39200 display “0L” (infinite)?

Go to Chart A.

Replace SRS

harness.

Go to Step 6

6

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 6

9J1–23

RESTRAINT CONTROL SYSTEM

DTC 19  Passenger Deployment Loop Short To Voltage

D09RW002

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 voltages at “Driver Bag Low”
terminal “4” and “Passenger Bag Low” terminal “16” to
detect short to B+ in the air bag assembly circuits.

DTC Will Set When:

“Ignition 1” is within the normal operating voltage range.
Once these conditions are met and the voltage at
“Passenger Bag Low” is above a specified value, DTC 19
will set.  This test is run once each ignition cycle and
“Continuous Monitoring”.

Action Taken:

SDM turns “ON” the “AIR BAG” 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 compartment.

4. This test determines whether the malfunction is in

CKT IB07–YEL/GRN.

RESTRAINT CONTROL SYSTEM

9J1–24

5. This test determines whether the malfunction is in

CKT 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
CKTs 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 CKT 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.

DTC 19 Passenger Deployment Loop Short To Voltage 

CAUTION: When DTC 19 has been set, it is necessary to replace the  SDM.  Setting DTC 19 and 25 or 51 or 53
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 voltage 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 J–39200

DVM with correct terminal adapter from J–35616–A.

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 passenger sense LO.

Is passenger sense LO more than 3.5 volts?

Go to Step 3

Go to Chart A.

3

1. Ignition switch “OFF.”
2. Disconnect passenger air bag assembly yellow 2–pin

connector behind the glove box assembly.

3. Leave driver air bag assembly connected.
4. Connect SRS driver / passenger load tool J–41433 and

appropriate adapter to passenger air bag assembly harness
connector.

5. Ignition switch “ON.”

Is passenger sense LO more than 3.5 volts?

Go to Step 4

Ignition switch

“OFF.”

Replace

passenger air

bag assembly.

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 from terminal

“15” to terminal “12” (IGNITION 1).

Does J–39200 display “0L” (infinite)?

Go to Step 5

Replace SRS

harness.

Go to Step 6

5

Measure resistance on SDM harness connector from terminal
“16” to terminal “12” (IGNITION 1).

Does J–39200 display “0L” (infinite)?

Go to Chart A.

Replace SRS

harness.

Go to Step 6

6

1. Reconnect all components, ensure all component are properly

mounted.

2. Ignition switch “ON.”

Is passenger sense LO less than 3.5 volts?

Ignition switch

“OFF.”Replace

SDM.Go to Step

7

Go to Chart A.

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