Code No.B1411 Passenger’s (front) air bag module (squib) system
(open circuit of squib circuit)
caution |
- If diagnosis code B1411 is set in the SRS-ECU, be sure to diagnose the
CAN bus line.
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Only when the frontal impact exceeding the
threshold is simultaneously detected (turned ON) by the front impact sensor
as well as by the analogue G-sensor and safing G-sensor in SRS-ECU, the
electric current is supplied from SRS-ECU to the passenger’s (front)
air bag module (squib).
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The code is set when the open circuit occurs to
the SRS-ECU passenger’s (front) air bag module (squib)
circuit.
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- Open circuit in the passenger’s (front) air bag module (squib)
circuit
- Poor contact of connector
- Malfunction of SRS-ECU
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STEP 1. M.U.T.-III CAN bus diagnostics.
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Use 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 54C - Troubleshooting ).
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STEP 2. M.U.T.-III diagnosis code.
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(1)Connect the negative battery terminal.
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(2)After erasing the diagnosis code memory, check the
diagnosis code again.
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(3)Disconnect the negative battery terminal.
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Q.
Is diagnosis code No. B1411 set?
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Go to Step 3.
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Intermittent malfunction (Refer to
GROUP 00 - How to Use Troubleshooting/Inspection Service Points
- How to Cope with Intermittent Malfunction ).
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STEP 3. Diagnosis check by dummy resistor connection.
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(1)Check that the negative battery terminal is disconnected.
If the negative battery terminal is connected, disconnect it.
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![](../../../img/52/ACE02052AB00ENG.png)
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(2)Use the flat-tipped screwdriver to pull out
the locking button of wiring harness side connector, and release the
lock.
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![](../../../img/52/AC301553DQ00ENG.png)
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(3)Connect the dummy resistor (Special tool:
MB991865) to the resistor harness (Special tool: MB991884). (4)Connect
the resistor harness (special tool) to right curtain air bag module
connector. (5)Connect the negative battery terminal. (6)After erasing
the diagnosis code memory, check the diagnosis code again.
Q.
Is diagnosis code No. B1411 set?
Go to Step 4.
Replace the passenger’s (front)
air bag module (Refer to ).
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STEP 4. Resistance measurement at the SRS-ECU connector and the
passenger’s (front) air bag module connector.
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(1)Check that the negative battery terminal is disconnected.
If the negative battery terminal is connected, disconnect it.
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(2)Disconnect the SRS-ECU connector.
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![](../../../img/52/ACE02052AB00ENG.png)
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(3)
danger |
To release the connector short spring in the
following operations, disconnect this harness side connector, and keep
the squib circuit shorted.
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Use the flat-tipped screwdriver to pull out the locking button of
wiring harness side connector, and release the lock.
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![](../../../img/52/ACE04216AH00ENG.png)
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(4)
caution |
The short spring may not be released due to the
insufficient insertion. Therefore, insert the insulator for 4 mm or
more.
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Insert an insulator (width: 3 mm, thickness: 0.5 mm) such as cable
tie between the ASQ+, ASQ- line, and then release the short
spring. (5)
caution |
Do not insert a probe directly into the terminal of
harness side connector from the connector front side as the connector
contact pressure may be weakened.
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Take the measurements below at the SRS-ECU connector and
passenger’s (front) air bag module connector harness side
connectors.
- Continuity ASQ- line between the SRS-ECU connector and the
passenger’s (front) air bag module connector.
- Continuity ASQ+ line between the SRS-ECU connector and the
passenger’s (front) air bag module connector.
OK: Continuity (less than 2 Ω)
Q.
Is the check result normal?
Go to Step 5.
Repair the wiring harnesses
ASQ+, ASQ- line between the passenger’s (front) air bag module
connector and the SRS-ECU connector.
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STEP 5. Check whether the diagnosis code is set again.
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Q.
Is diagnosis code No. B1411 set?
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Replace SRS-ECU (Refer to ).
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Intermittent malfunction (Refer to
GROUP 00 - How to Use Troubleshooting/Inspection Service Points
- How to Cope with Intermittent Malfunction ).
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