Code No.B1450: Curtain air bag module (LH) (squib) system (short-circuited between terminals of the squib circuit)




OPERATION



DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Improper engaged connector or defective short spring*
  • Short circuit between the curtain air bag module (LH) (squib) circuit terminals
  • Damaged connector(s)
  • Malfunction of the SRS-ECU
note *: The squib circuit connectors integrate a "short" spring (which prevents the air bag from deploying unintentionally due to static electricity by shorting the positive wire to the earth wire in the squib circuit when the connectors are disconnected).Therefore, if connector C-153, C-156 C-157 or D-33 is damaged or improperly engaged, the short spring may not be released when the connector is connected.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.

Q. Is diagnosis code B1519 set?
Go to Step 2.
Go to Step 3.

STEP 2. Connector lock check: SRS-ECU connector C-153. (M.U.T.-III diagnosis code)
(1)Disconnect the negative battery terminal.

(2)Disconnect the connectors C-153 and then reconnect them.
(3)Connect the negative battery terminal.
(4)Erase the diagnosis code memory, and check the diagnosis code.

Q. Is diagnosis code B1450 set?

Go to Step 3.

The procedure is complete. It is assumed that diagnosis code B1450 set as connector C-153 was engaged improperly.

STEP 3. Connector lock check: SRS-ECU connector C-153, intermediate connector C-156, C-157 and curtain air bag module (LH) connector D-33. (M.U.T.-III diagnosis code)
(1)Disconnect the negative battery terminal.






(2)Disconnect connectors C-153, C-156 and C-157 and then reconnect them. Slide the outer hosing of intermediate connector C-156 and C-157 in the arrow direction shown.



(3)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. Then, reconnect the connector.
(4)Connect the negative battery terminal.
(5)Erase the diagnosis code memory, and check the diagnosis code.

Q. Is diagnosis code B1450 set?

Go to Step 4.

The procedure is complete. It is assumed that diagnosis code B1450 set as connector C-153, C-156, C-157 or D-33 was engaged improperly.

STEP 4. 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 B1450 set?

Go to Step 5.

Replace the curtain air bag module (LH) (Refer to ).

STEP 5. Resistance measurement at 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 and 2.
OK: Open circuit

Q. Is the check result normal?

Go to Step 6.

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 6. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1450 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).