Code No.B1450 Curtain air bag module (squib) (LH) system
(short-circuited between terminals of the squib circuit)
![](../../../img/52/W4X52E011A00ENG.png)
caution |
If diagnosis code B1450 is set in the
SRS-ECU, always diagnose the CAN bus lines.
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OPERATION
The SRS-ECU judges how severe a collision is by
detecting signals from the side impact sensors and the side-airbag
safing G-sensor. If the impact is over a predetermined level, the
SRS-ECU outputs an ignition signal. At this time, if the side-airbag
safing G-sensor is on, the curtain air bag module will deploy.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if
one curtain air bag module squib (LH) wire shorted to the other.
PROBABLE CAUSES
- Improper engaged connector or defective short
spring*
- Short circuit between the curtain air bag module (squib) (LH)
circuit terminals
- Damaged connector(s)
- Malfunction of the SRS-ECU
note |
*: The squib circuit connectors
integrate a "short" spring (which prevents the air bag from
deploying unintentionally due to static electricity by
shorting the positive wire to the earth wire in the squib
circuit when the connectors are disconnected). Therefore, if
connector C-120, G-22 or G-01 is damaged or improperly
engaged, the short spring may not be released when the
connector is connected.
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STEP 1. M.U.T.-III CAN bus diagnostics
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Use the M.U.T.-III to diagnose the
CAN bus lines.
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Q.
Is the check result normal?
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Go to Step
2.
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Repair the CAN bus
line (Refer to GROUP 54F, Diagnosis ).
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STEP 2. Check whether the diagnosis code is
reset.
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Check again if the diagnosis code
is set.
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(1)Erase the diagnosis code.
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(2)Ignition: LOCK (OFF) position to ON
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(3)On completion, check that the diagnosis code is
not reset.
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Q.
Is the diagnosis code set?
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Go to Step
3.
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There is an
intermittent malfunction such as poor engaged connector(s)
or open circuit (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
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STEP 3. M.U.T.-III diagnosis code
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caution |
To prevent damage to
M.U.T.-II/III, always turn the ignition
switch to the "LOCK" (OFF) position before
connecting or disconnecting
M.U.T.-II/III.
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(1)Turn the ignition switch to the "ON"
position.
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(2)Check if the diagnosis code is set.
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(3)Turn the ignition switch to the "LOOK" (OFF)
position.
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Q.
Is diagnosis code B1519 set?
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Go to Step
4.
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Go to Step
5.
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STEP 4. Connector lock check: SRS-ECU connector C-120
(M.U.T.-III diagnosis code)
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC311438AE00ENG.png)
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(2)Disconnect connectors C-120, and
then reconnect them. (3)Connector the negative battery
terminal. (4)Erase the diagnosis code memory, and check
the diagnosis code.
Q.
Is diagnosis code B1450 set?
Go to Step
5.
The
procedure is complete. It is assumed that diagnosis code
B1450 set as connector C-120 was engaged
improperly.
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STEP 5. STEP 5. Connector lock check: SRS-ECU connector
C-120, curtain air bag module (LH) connector G-01 and
intermediate connector G-22 (M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC311438AE00ENG.png)
![](../../../img/52/AC302576AE00ENG.png)
![](../../../img/52/AC303223AC00ENG.png)
![](../../../img/52/AC208384AN00ENG.png)
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(2)Disconnect connectors C-120,
G-22 and G-01, and then reconnect them. For connector G-01,
use a flat-tipped screwdriver to pull out the locking button
at the harness side connector, and then disconnect the
connector. (3)Connector the negative battery
terminal. (4)Erase the diagnosis code memory, and check
the diagnosis code.
Q.
Is diagnosis code B1450 set?
Go to Step
6.
The
procedure is complete. It is assumed that diagnosis code
B1450 set as connector C-120, G-22 or G-01 was engaged
improperly.
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STEP 6. Check the intermediate connector. (M.U.T.-III
diagnosis code)
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC302576AE00ENG.png)
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(2)Remove the intermediate
connector G-22 (connection between curtain air bag harness
and floor harness).
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![](../../../img/52/AC006042CA00ENG.png)
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(3)Connect special tool dummy
resistor (MB991865) to special tool resistor harness
(MB991866). (4)
caution |
Do not insert a test probe
into the terminal from its front side directly
as the connector contact pressure may be
weakened.
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Insert special tool resistor harness probe into
intermediate connector G-22 (floor harness side) by
backprobing. (5)Connect the negative battery
terminal. (6)Erase diagnosis code memory, and then check
the diagnosis code.
Q.
Is diagnosis code B1450 set?
Go to Step
7.
Go to Step
8.
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STEP 7. Check the curtain air bag module (LH) circuit.
Resistance measurement at the SRS-ECU connector
C-120.
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![](../../../img/52/AC311438AE00ENG.png)
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(1)Disconnect SRS-ECU connector
C-120.
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![](../../../img/52/AC302576AE00ENG.png)
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(2)
danger |
To prevents the air bag from
deploying unintentionally, disconnect the
intermediate connector G-22 to short the squib
circuit.
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Disconnect the intermediate connector G-22.
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![](../../../img/52/AC301604AC00ENG.png)
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(3)
caution |
Insert an insulator such as a
cable tie to a depth of 4mm or more, otherwise
the short spring will not be released.
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Insert a cable tie [3 mm wide, 0.5 mm
thick] between terminals 5, 6 and the short spring to
release the short spring.
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![](../../../img/52/AC301560AC00ENG.png)
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(4)
caution |
Do not insert a test probe
into the terminal from its front side directly
as the connector contact pressure may be
weakened.
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Resistance measurement between C-120 harness side
connector terminals 5 and 6. OK: Open
circuit
Q.
Is the check result normal?
Go to Step
9.
Repair
the harness wire between SRS-ECU connector C-120 (terminal
No.5 and 6) and intermediate connector G-22 (terminal No.1
and 2).
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STEP 8. Check the curtain air bag module (LH) circuit.
Resistance measurement at the intermediate connector
G-22.
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC303223AC00ENG.png)
![](../../../img/52/AC208384AN00ENG.png)
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(2)
danger |
To prevents the air bag from
deploying unintentionally, disconnect the
curtain air bag module (LH) connector G-01 to
short the squib circuit.
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Disconnect curtain air bag module (LH) connector
G-01. Use a flat-tipped screwdriver to unlock the locking
button at the harness side connector by withdrawing it
toward you in two stages, and then disconnect the
connector.
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![](../../../img/52/AC302576AE00ENG.png)
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(3)Disconnect the intermediate
connector G-22.
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![](../../../img/52/AC303537AF00ENG.png)
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(4)
caution |
Insert an insulator such as a
cable tie to a depth of 4mm or more, otherwise
the short spring will not be released.
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Insert a cable tie [3 mm wide, 0.5 mm
thick] between terminals 1, 2 and the short spring to
release the short spring.
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![](../../../img/52/AC303985AC00ENG.png)
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(5)
caution |
Do not insert a test probe
into the terminal from its front side directly
as the connector contact pressure may be
weakened.
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Resistance measurement between G-22 rear floor
harness connector terminals 1 and 2. OK: Open
circuit
Q.
Is the check result normal?
Replace the curtain
air bag module (LH). (Refer to ).
Repair the
harness wire between rear floor harness connector G-22
(terminal No.1 and 2) and curtain air bag module (LH)
connector G-01 (terminal No.1 and 2).
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STEP 9. Check whether the diagnosis code is
reset.
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Q.
Is diagnosis code B1450 set?
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Replace the SRS-ECU.
(Refer to ).
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The procedure is
complete. If no malfunctions are found in all steps, an
intermittent malfunction is suspected (Refer to GROUP 00,
How to Use Troubleshooting/Inspection Service Points
).
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