Code No.3A: Curtain
air bag module (squib) (RH) system (short-circuited between
terminals of the squib circuit)
![](../../../img/52/W4X52X014A00ENG.png)
OPERATION
The SRS-ECU judges how severe a collision is by
detecting signals from the side impact
sensors and the side air bag safing G-sensor. If the impact is over a
predetermined level, the
SRS-ECU outputs an ignition signal. At this time, if the side air bag
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 (RH) wire shorted to the
other. However, if no diagnosis code resets, the SRS warning lamp will
be switched off (diagnosis
code will be retained).
PROBABLE CAUSES
- Improper engaged connector or defective short
spring*
- Short circuit between the curtain air bag module (squib) (RH)
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-146or G-04 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 diagnosis code
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Q.
Is diagnosis code 34 set?
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Go to Step
2.
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Go to Step
3.
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STEP 2. Connector lock check: SRS-ECU connector C-146
(M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC311438AG00ENG.png)
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(2)Disconnect connectors C-146, 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 3A set?
Go to Step
4.
The
procedure is complete. It is assumed that diagnosis code 3A
set as connector
C-146 was engaged improperly.
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STEP 3. Connector lock check: SRS-ECU connector C-146
and curtain
air bag module connector G-04 (M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC311438AG00ENG.png)
![](../../../img/52/AC313481AL00ENG.png)
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(2)Disconnect connectors C-146 and
G-04, and then reconnect them. For connector G-04, 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 3A set?
Go to Step
4.
The
procedure is complete. It is assumed that diagnosis code 3A
set as connector
C-146 or G-04 was engaged improperly.
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STEP 4. Check the diagnosis code by connecting a dummy
resistor (M.U.T.-III
diagnosis code).
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC313481AL00ENG.png)
![](../../../img/52/AC208384AO00ENG.png)
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(2)Disconnect curtain air bag
module connector G-04. Use a flat-tipped screwdriver to pull
out the locking button at the harness side connector, and
then disconnect the connector.
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![](../../../img/52/AC301553AK00ENG.png)
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(3)Connect special tool dummy
resistor (MB991865) to special tool resistor harness
(MB991884). (4)Connect special tool (MB991884) to the
G-04 harness side connector. (5)Connect the negative
battery terminal. (6)Erase diagnosis code memory, and
then check the diagnosis code.
Q.
Is diagnosis code 3A set?
Go to Step
5.
Replace
the curtain air bag module (Refer to ).
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STEP 5. Resistance measurement at the SRS-ECU connector
C-146.
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(1)Disconnect the negative battery
terminal.
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![](../../../img/52/AC311438AG00ENG.png)
![](../../../img/52/AC313481AL00ENG.png)
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(2)Disconnect SRS-ECU connector
C-146.
danger |
To prevents the air bag from
deploying unintentionally, disconnect the
curtain air bag
module connector G-04 to short the squib
circuit.
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![](../../../img/52/AC208384AO00ENG.png)
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(3)Disconnect curtain air bag
module connector G-04. Use a flat-tipped screwdriver to pull
out the locking button at the harness side connector, and
then disconnect the connector.
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![](../../../img/52/AC208765AF00ENG.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
bar will not be released.
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Insert a cable tie [3 mm wide, 0.5 mm
thick]
between terminals 29, 30
and the short bar to release the short spring.
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![](../../../img/52/AC006244AV00ENG.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 C-146 harness side
connector terminals 29 and 30. OK: Open
circuit
Q.
Is the check result normal?
Go to Step
6.
Repair
the harness wire between SRS-ECU connector C-146 (terminal
No.29 and 30)
and curtain air bag module connector G-04 (terminal No.1and
2).
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STEP 6. Check whether the diagnosis code is
reset.
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Q.
Is diagnosis code 3A set?
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Replace the SRS-ECU
(Refer to ).
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An intermittent
malfunction is suspected (Refer to GROUP 00, How to Use
Troubleshooting/Inspection
Service Points ).
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