Code No.B1430: Side-Airbag Module (LH) (Squib) System Fault 1 (Short
Circuit between Terminals of the Squib Circuit)
| caution |
If diagnosis code B1430 is set in the
combination meter, 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 left and right side impact sensors. If the
impact is over a predetermined level, the SRS-ECU sends an
ignition signal. At this time, if the side-airbag safing
G-sensor is on, the SRS side-airbag will inflate.
- The ignition signal is input to the side-airbag module to
inflate the side-airbag.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if
there is abnormal resistance between the input terminals of the
side-airbag module (LH) (squib).
PROBABLE CAUSES
- Improper engaged connector or defective short
spring*
- Short circuit between the side-airbag module (LH) (squib)
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). (Refer to  ).
Therefore, if connector C-120 or D-22 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
lines (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.-III MB991958, always turn the ignition
switch to the "LOCK" (OFF) position before
connecting or disconnecting M.U.T.-III
MB991958.
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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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(2)Disconnect connectors C-120 and
then reconnect them.
(3)Connect the negative battery
terminal.
(4)Erase the diagnosis code memory, and check
the diagnosis code.
Q.
Is diagnosis code B1430 out put?
Go to Step
5.
The
procedure is complete. It is assumed that diagnosis code
B1430 set as connector C-120 was engaged
improperly.
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STEP 5. Connector lock check: SRS-ECU connector C-120
and side-airbag module (LH) connector D-22 (M.U.T.-III
diagnosis code).
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(1)Disconnect the negative battery
terminal.
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(2)Disconnect connectors C-120 and
D-22 and then reconnect them.
(3)Connect the negative
battery terminal.
(4)Erase the diagnosis code memory, and
check the diagnosis code.
Q.
Is diagnosis code B1430 out put?
Go to Step
6.
The
procedure is complete. It is assumed that diagnosis code
B1430 set because connector C-120 or D-22 was engaged
improperly.
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STEP 6. Check the side-airbag module (LH). (M.U.T.-III
diagnosis code).
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(1)Disconnect the negative battery
terminal.
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(2)Disconnect the side-airbag
module (LH) connector D-22.
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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 MB991866 into the D-22 harness
side connector by backprobing.
(5)Connect the negative
battery terminal.
(6)Erase diagnosis code memory, and
check the diagnosis code.
Q.
Is diagnosis code B1430 set?
Go to Step
7.
Replace
the frame assembly of the front seat (LH) (Refer to GROUP
52A, Front Seat ).
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STEP 7. Check the side-airbag module (LH) circuit.
Resistance measurement at the SRS-ECU connector
C-120.
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(1)Disconnect SRS-ECU connector
C-120.
(2)
| danger |
To prevent the air bag from
deploying unintentionally, disconnect the
side-airbag module (LH) connector D-22 to short
the squib circuit.
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Disconnect left hand side-airbag module (LH)
connector D-22.
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(3)
| caution |
Insert an insulator such as a
cable tie to a depth of 4mm (0.16 inch) 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 9, 10 and the short spring to
release the short spring.
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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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Check for continuity between C-120 harness side
connector terminals 9 and 10.
OK: Open
circuit
Q.
Is the check result normal?
Go to Step
8.
Repair
the harness wires between SRS-ECU connector C-120 (terminal
No.9 and 10) and side-airbag module (LH) connector D-22
(terminal No.1 and 2).
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STEP 8. Check whether the diagnosis code is
reset.
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Q.
Is diagnosis code B1430 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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