Code No.B1461: Seat Belt Pre-Tensioner (RH) (Squib) System Fault 2 (Open
in the Squib Circuit)
![](../../../img/52/W4X52E018A00ENG.png)
caution |
If diagnosis code B1461 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
pre-tensioner will deploy.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if there
is abnormal resistance between the input terminals of the seat belt
pre-tensioner (RH) (squib).
PROBABLE CAUSES
- Open circuit in the seat belt pre-tensioner (RH) (squib) circuit
- Improper connector contact
- 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 seat belt pre-tensioner (RH) (M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery terminal.
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![](../../../img/52/AC302394AC00ENG.png)
![](../../../img/52/AC103556AX00ENG.png)
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(2)Disconnect seat belt pre-tensioner connector
(RH) D-32. Use a flat-tipped screwdriver to unlock the locking button at
the harness side connector by withdrawing it toward you in two stages, and
then disconnect the connector.
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![](../../../img/52/AC103283AU00ENG.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 D-32 harness side connector. (5)Connect the
negative battery terminal. (6)Erase diagnosis code memory, and then
check the diagnosis code.
Q.
Is diagnosis code B1461 set?
Go to Step 4.
Replace the passenger’s seat
belt pre-tensioner (RH) (Refer to ).
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STEP 4. Resistance measurement between SRS-ECU connector C-118
(terminal No.59 and 60) and the seat belt pre-tensioner (RH) connector
D-32 (terminal No.1 and 2).
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![](../../../img/52/AC311438AC00ENG.png)
![](../../../img/52/AC302394AC00ENG.png)
![](../../../img/52/AC103556AX00ENG.png)
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(1)Disconnect SRS-ECU connector C-118 and seat
belt pre-tensioner (RH) connector D-32. For connector D-32, use a
flat-tipped screwdriver to unlock the locking button at the harness side
connector by withdrawing it toward you in two stages, and then disconnect
the connector.
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![](../../../img/52/AC201287BG00ENG.png)
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(2)Connect D-32 harness side connector to
special tool resistor harness (MB991884).
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![](../../../img/52/AC304737AE00ENG.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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Check for continuity between the following
terminals.
- SRS-ECU connector C-118 (terminal No.59) and the special tool
(terminal No.1)
- SRS-ECU connector C-118 (terminal No.60) and the special tool
(terminal No.2)
OK: Less than 2 Ω
Q.
Are the check results normal?
Go to Step 5.
Repair the harness wires between
SRS-ECU connector C-118 (terminal No.59 and 60) and seat belt pre-tensioner
(RH) connector D-32 (terminal No.1 and 2).
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STEP 5. Check whether the diagnosis code is reset.
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Q.
Is diagnosis code B1461 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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