Code No.B1452: Curtain air bag module (LH) (squib) system (short-circuited to the earth)




OPERATION



DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Short to the earth in the curtain air bag module (LH) (squib) harness
  • Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the diagnosis code by connecting a dummy resistor. (M.U.T.-III diagnosis code)
(1)Disconnect the negative battery terminal.



(2)Use the flat-tipped screwdriver to pull out the locking button of D-33 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 D-33 harness side connector.
(5)Connect the negative battery terminal.
(6)Erase the diagnosis code memory, and check the diagnosis code.

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 SRS-ECU connector C-153.
(1)Disconnect the negative battery terminal.

(2)Disconnect SRS-ECU connector C-153.



(3)
danger To prevents the air bag from deploying unintentionally, disconnect the curtain air bag module (LH) connector D-33 to short the squib circuit.
Use the flat-tipped screwdriver to pull out the locking button of D-33 harness side connector to the direction of the arrow. After releasing the lock, disconnect the connector.

(4)
caution Insert an insulator such as a cable tie to a depth of 7 mm or more, otherwise the short spring will not be released.
Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 1, 2 and the short spring to 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.
Resistance measurement between C-153 harness side connector terminals 1, 2 and body earth.
OK: Open circuit

Q. Is the check result normal?

Go to Step 3.

Repair the harness wires between SRS-ECU connector C-153 (terminal No.1 and 2) and curtain air bag module (LH) connector D-33 (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 ).