Code No.B1451:
Curtain air bag module (LH) (squib) system (open-circuited in the squib circuit)
OPERATION
In case of side collision, when the impact exceeding the threshold is applied to the vehicle,
and when the impact is simultaneously detected (turned ON) by the side impact sensor as well
as by the analog G-sensor in SRS-ECU, the electric current is supplied from SRS-ECU to the curtain
air bag module (squib) of impacted side.
TROUBLE JUDGEMENT
The code is set when the open circuit occurs to the SRS-ECU curtain air bag module (squib)
circuit.
PROBABLE CAUSES
Open circuit to the curtain air bag module (squib) circuit
Damaged connector(s)
Malfunction of SRS-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check the diagnosis code by connecting a dummy resistor.
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative
auxiliary battery terminal is connected, disconnect it.
(2)Use the flat-tipped screwdriver to pull out the locking button of C-10 harness side connector
to the direction of the arrow. After releasing the lock, disconnect the connector. Then, reconnect
the connector.
(3)Connect the dummy resistor (Special tool: MB991865) to the resistor harness (Special tool:
MB991884). (4)Connect special tool (MB991884) to the C-10 harness side connector. (5)Connect the negative auxiliary battery terminal. (6)After erasing the diagnosis code memory, check the diagnosis code again. (7)Disconnect the negative auxiliary battery terminal.
Q.
Is diagnosis code B1451 set?
Go to Step 2
Replace the curtain air bag module (LH) (Refer to ).
STEP 2. Resistance measurement between the B-113 SRS-ECU connector
(terminal No.1 and 2) and the C-10 curtain air bag module (LH) connector (terminal No.1 and
2).
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative
auxiliary battery terminal is connected, disconnect it.
(2)Disconnect the B-113 SRS-ECU connector.
(3)
danger
To release SRS-ECU wiring harness side connector short
spring in the following operations, disconnect air bag module connector in advance, and keep
the squib circuit shorted.
Use the flat-tipped screwdriver to pull out the locking button of C-10 harness side connector
to the direction of the arrow. After releasing the lock, disconnect the connector. Then, reconnect
the connector.
(4)
caution
The short spring may not be released due to the insufficient insertion. Therefore, insert
the insulator for 4 mm or more.
Insert an insulator (width: 3 mm, thickness: 0.5 mm) such as cable tie between the terminal
1/2 and the short spring, and release the short spring.
(5)Connect C-10 harness side connector to special tool resistor harness (MB991884). (6)
caution
Do not insert a test probe into the
terminal from its front side directly as the connector contact pressure may be weakened.
Take the following measurements.
Continuity between B-113 SRS-ECU wiring harness side
connector terminal No. 1 and the resistor harness connector terminal No. 2
Continuity between B-113 SRS-ECU wiring harness side connector terminal No. 2 and
the resistor harness connector terminal No. 1
OK: Continuity (Less than 2 Ω)
Q.
Are the check results normal?
Go to Step 3
Repair the harness wires between B-113 SRS-ECU connector (terminal No.1 and 2)
and C-10 curtain air bag module (LH) connector (terminal No.1 and2).
STEP 3. Check whether the diagnosis code is reset.
Q.
Is diagnosis code B1441 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
)
)
)
)
)
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Go to Step 2
Replace the curtain air bag module (LH) (Refer to 
).)
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