Code No. B1625:
Front passenger’s lap pre-tensioner (squib) system (short
circuit between squib circuit
terminals)
caution |
If diagnosis code No. B1625
is set in the SRS-ECU, be sure to diagnose the CAN bus
line.
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Only when the frontal collision
impact that exceeds the threshold is simultaneously detected
(turned ON) by the front impact sensor as well as by the
analogue G-sensor in SRS-ECU, the electric
current is supplied from SRS-ECU to the lap pre-tensioner
(squib).
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The code is set when the short
circuit occurs to between the terminals of SRS-ECU lap
pre-tensioner (squib) circuit.
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- Damaged short spring *
- Short circuit between terminals of lap pre-tensioner
(squib) circuit
- Damaged connector(s)
- Malfunction of SRS-ECU
- Insufficient press of locking button or locking
button not pressed
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note |
*: The squib circuit
connectors integrate a short spring (which
prevents the
air bags from being unintentionally deployed
because of static electricity by shorting the
positive wire
to the earth wire in the squib circuit when the
connectors are disconnected). Therefore, when
the above codes are set, the short spring may
not be released due to the damaged connector
even
when the connectors are connected.
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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. Check whether the diagnosis code is set
again.
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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. B1625 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. Connector check: SRS-ECU, lap
pre-tensioner
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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)After disconnecting the SRS-ECU connector,
connect it again.
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![](../../../img/52/AC608270AB00ENG.png)
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(3) After disconnecting the lap
pre-tensioner harness side connector, connect the connector
again. For the lap pre-tensioner harness side connector
disconnection, use the flat-tipped screwdriver
to pull out the harness side connector locking button. After
releasing the lock, disconnect
the harness side connector. (4)Connect the negative
battery terminal. (5)After erasing the diagnosis code
memory, check the diagnosis code again. (6)Disconnect the
negative battery terminal.
Q.
Is diagnosis code No. B1625 set?
Go to Step
4.
Replace
the connector concerned.
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STEP 4. 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/AC608270AB00ENG.png)
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(2)Use the flat-tipped screwdriver
to pull out the locking button of harness side connector.
After releasing the lock, disconnect the lap pre-tensioner
harness side connector.
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![](../../../img/52/AC301553DR00ENG.png)
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(3)Connect special tool dummy
resistor (MB991865) to special tool resistor harness
(MB991884). (4)Connect special tool resistor harness
(MB991884) to the lap pre-tensioner harness
side connector. (5)Connect the negative battery
terminal. (6)After erasing the diagnosis code memory,
check the diagnosis code again. (7)Disconnect the
negative battery terminal.
Q.
Is diagnosis code No. B1625 set?
Go to Step
5.
Replace
the seat belt with pre-tensioner.
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STEP 5. Resistance measurement at the SRS-ECU
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/AC608270AB00ENG.png)
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(3)
danger |
To release the SRS-ECU
connector short spring in the following
operations, disconnect this lap pre-tensioner
connector, and keep the squib circuit
shorted.
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Use the flat-tipped screwdriver to pull out the
locking button of harness side connector.
After releasing the lock, disconnect the lap pre-tensioner
harness side connector.
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![](../../../img/52/ACE04216AK00ENG.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 PA2-,
PA2+, and then release the short spring. (5)Take
the measurements below at the SRS-ECU harness side
connector.
- Continuity between PA2-, PA2+ line
OK: No continuity
Q.
Is the check result normal?
Go to Step
6.
Repair
the wiring harness PA2-, PA2+ line between the SRS-ECU
connector
and the lap pre-tensioner connector.
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STEP 6. Check whether the diagnosis code is set
again.
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Q.
Is diagnosis code No. B1625 set?
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Replace
SRS-ECU.
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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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