Isuzu KB P190. Manual — part 1431

9A1-42 RESTRAINT CONTROL SYSTEM

DTC B0029 (Flash Code 29) Passenger Pretensioner Squib Circuit High Resistance

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. Check the passenger pretensioner circuit for open.

2. If the problem found, repair as necessary.
Was a problem found?

Verify repair

Go to Step 3

3

1. Ignition switch is at “LOCK”.

2. Make sure the passenger air bag assembly yellow connector

located at the base of the passenger seat.

Is the yellow connector connected properly?

Go to Step 4

Seat passenger

pretensioner

assembly yellow

connector

properly.

Go to Step 7

4

1. Disconnect and inspect the passenger pretensioner assembly

yellow connector located at the base of the passenger seat.

2.

If ok, reconnect the passenger pretensioner assembly
connector.

3. Ignition switch “ON”.
Is DTC B0029 current?

Go to Step 5

Go to Step 7

5

1. Ignition switch is at “LOCK”.

2.

Disconnect passenger pretensioner assembly, yellow
connector located at the base of the passenger seat.

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

appropriate adapters to passenger pretensioner assembly
harness connectors.

4. Ignition switch “ON”.
Is DTC B0029 Current?

Go to Step 6

Ignition switch is at

“LOCK.”

Replace the

passenger

pretensioner

assembly.

Go to Step 7

6

1. Ignition switch is at “LOCK”.

2. There has been an increase in the total circuit resistance of

the passenger loop.

3. Use the high resolution ohmmeter mode of the DVM while

checking circuits “Pasenger Pretensioner High” and
“Passenger Pretensioner Low”, and SRS control unit
connector terminal “11” and “10” to locate the root cause.

Was a fault found?

Replace SRS

harness or repair

chassis harness.

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”

―

RESTRAINT CONTROL SYSTEM 9A1-43

DTC B0031 (Flash Code 31) Passenger Pretensioner Squib Circuit Low
Resistance

RTW79ALF000301

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 Pretensioner Low” terminal “10” is
grounded through a resistor and the passenger current
source connected to “Passenger Pretensioner High”
terminal “11” allows a known amount of current to flow.

By monitoring the voltage difference between
“Passenger Pretensioner High” and “Passenger
Pretensioner Low”, the SRS control unit calculates the
combined resistance of the passenger air bag
assembly, harness wiring circuits “Passenger
Pretensioner High” and “Passenger Pretensioner Low”
connector terminal contact.

9A1-44 RESTRAINT CONTROL SYSTEM

DTC Will Set When

The combined resistance of the passenger pretensioner
assembly, harness wiring circuits “Passsenger
Pretensioner High” and “Passenger Pretensioner 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.

DTC Will Clear When

The ignition switch is turned “LOCK”.

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

pretensioner 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 Pretensioner High” and
“Passenger Pretensioner Low” or a malfunctioning
shorting clip on the passenger pretensioner assembly
which would require replacement of the pretensioner
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.

RESTRAINT CONTROL SYSTEM 9A1-45

DTC B0031 (Flash Code 31) Passenger Pretensioner 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 pretensioner squib circuit for short to

valtage or short to ground.

2. If the broblem found, repair as necessary.
Was a problem found?

Verify repair

Go to Step 3

3

1. Ignition switch is at “LOCK”.

2. Make sure the passenger air bag assembly yellow connector

located at the base of the passenger seat.

Is the yellow connector connected properly?

Go to Step 4

Seat passenger

pretensioner

assembly yellow

connector

properly.

Go to Step 7

4

1. Disconnect and inspect the passenger air bag assembly

yellow connector located at the base of the passenger seat.

2. If ok, reconnect the passenger air bag assembly connector.

3. Ignition switch is at “ON”.
Is DTC B0031 Current?

Go to Step 5

Go to Step 7

5

1. Ignition switch is at “LOCK”.

2. Disconnect SRS coil and passenger pretensioner assembly,

yellow connector located at the base of the passenger seat.

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

appropriate adapters to passenger pretensioner assembly
harness connectors.

4. Ignition switch is at “ON”.
Is DTC B0031 current?

Go to Step 6

Ignition switch is at

“OFF”.

Replace the

passenger

pretensioner

assembly.

Go to Step 7

6

1. Ignition switch is at “LOCK”.

2. There has been a decrease in the total circuit resistance of

the passenger inflator deployment loop.

3. Use the high resolution ohmmeter mode of the DVM while

checking circuits “Passenger pretensioner High” and
“Passenger Pretensioner Low”, and SRS control unit
connector terminal “11” and “10” to locate the root cause.

Was a fault found?

Replace SRS

harness or repair

chassis harness.

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”

―