Code No.B1452:
Curtain air bag module (LH) (squib) system (short-circuited to the earth)
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 input terminal of SRS-ECU curtain air bag module (squib) is shorted
to earth.
PROBABLE CAUSES
Damaged wiring harness and connector
Curtain air bag module (squib) harness shorted to earth
Malfunction of SRS-ECU
DIAGNOSIS PROCEDURE
STEP 1. Diagnosis check by dummy resistor connection.
(1)Check that the negative battery terminal is disconnected. If the negative 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.
(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 battery terminal. (6)After erasing the diagnosis code memory, check the diagnosis code again. (7)Disconnect the negative battery terminal.
Q.
Is diagnosis code B1452 set?
Go to Step 2
Replace the curtain air bag module (LH) (Refer to ).
STEP 2. Resistance measurement at the B-113 SRS-ECU connector.
(1)Check that the negative battery terminal is disconnected. If the negative 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.
(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)
caution
Do not insert a test probe into the terminal from
its front side directly as the connector contact pressure may be weakened.
Check the continuity between the B-113 harness side connector terminal No. 1/2
and the body earth. OK: No continuity
Q.
Is the check result 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 and 2).
STEP 3. Check whether the diagnosis code is reset.
Q.
Is diagnosis code B1452 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
)
)
)
)
)
)
)
Go to Step 2
Replace the curtain air bag module (LH) (Refer to 
). )
