Code No.B1441: Curtain air bag module (RH) (squib) system (open-circuited in the squib circuit)












OPERATION



TROUBLE JUDGEMENT



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-03 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-03 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 B1441 set?

Go to Step 2

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

STEP 2. Resistance measurement between the B-111 SRS-ECU connector (terminal No.55 and 56) and the C-03 curtain air bag module (RH) connector (terminal No.2 and 1).
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative auxiliary battery terminal is connected, disconnect it.
(2)Disconnect the B-111 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-03 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 55/56 and the short spring, and release the short spring.

(5)Connect C-03 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-111 SRS-ECU wiring harness side connector terminal No. 55 and the resistor harness connector terminal No. 2
  • Continuity between B-111 SRS-ECU wiring harness side connector terminal No. 56 and the resistor harness connector terminal No. 1
OK: Continuity (less than 2 Ω)

Q. Is the check result normal?

Go to Step 3

Repair the harness wires between B-111 SRS-ECU connector (terminal No.55 and 56) and C-03 curtain air bag module (RH) connector (terminal No.2 and1).

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 ).