Code No.B1413 Passenger’s (Front) Air Bag Module (1st Squib) System
Fault for Power Supply Circuit (Short-Circuited to Power Supply)
![](../../../img/52/W4X52X003A00ENG.png)
caution |
If diagnosis code B1413 is set in the SRS-ECU, always
diagnose the CAN main bus line.
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OPERATION
- The SRS-ECU judges how severe a collision is by detecting signals from
the front impact sensors and the front air bag analogue G-sensor. If the
impact is over a predetermined level, the SRS-ECU sends an ignition signal.
At this time, if the front air bag safing G-sensor is on, the SRS air bag
will inflate.
- The ignition signal is input to the air bag module to inflate the air
bag.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if there
is abnormal resistance between the input terminals of the passenger’s
air bag module (squib).
PROBABLE CAUSES
- Damaged harness wires and connectors
- Short to the power supply in the passenger’s air bag module (squib)
harness
- Malfunction of the SRS-ECU
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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. Check the passenger’s air bag module (M.U.T.-III
diagnosis code).
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(1)Disconnect the negative battery terminal.
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![](../../../img/52/AC311373AE00ENG.png)
![](../../../img/52/AC311375AC00ENG.png)
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(2)Disconnect the passenger’s air bag
module connector C-132.
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![](../../../img/52/AC006042CE00ENG.png)
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(3)
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 harness side connector C-132
(terminal No.1 and 2) by backprobing. (4)Connect the negative battery
terminal. (5)Erase the diagnosis code memory, and check the diagnosis
code.
Q.
Is the checked diagnosis code set?
Go to Step 4.
Replace the
passenger’s air bag module (Refer to ). Then go to Step 5.
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STEP 4. Check the passenger’s air bag module circuit. Measure the
voltage at the SRS-ECU connector C-119.
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![](../../../img/52/AC311438AD00ENG.png)
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(1)Disconnect SRS-ECU connector C-119.
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![](../../../img/52/AC311373AE00ENG.png)
![](../../../img/52/AC311375AC00ENG.png)
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(2)
danger |
To prevent the air bag from deploying
unintentionally, disconnect the passenger’s air bag module
connector C-132 to short the squib circuit.
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Disconnect the passenger’s air bag module connector
C-132. (3)Turn the ignition switch to the "ON" position.
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![](../../../img/52/AC301588AF00ENG.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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Measure the voltage between C-119 harness side connector terminals
27 and 28 and body earth. OK: 0 V
Q.
Is the check result normal?
Erase the diagnosis code memory,
and check the diagnosis code. If diagnosis code B1413 sets, replace the
SRS-ECU (Refer to ). Then go to Step 5.
Replace the
harness wires between SRS-ECU connector C-119 and passenger’s air bag
module connector C-132. Then go to Step 5.
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STEP 5. Check whether the diagnosis code is reset.
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Q.
Is diagnosis code B1413 set?
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Return to Step 1.
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The
procedure is complete.
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