Code No.B1440: Curtain air bag module (RH) (squib) system (short-circuit between terminals of the squib circuit)
















OPERATION



TROUBLE JUDGEMENT



PROBABLE CAUSES



  • Damaged short spring *
  • Short circuit between terminals of curtain air bag module (squib) circuit
  • Damaged connector(s)
  • Malfunction of SRS-ECU
note *: The squib circuit connectors integrate a short spring (which prevents the air bags from being unintentionally deployed because of static electricity by shorting the positive wire to the earth wire in the squib circuit when the connectors are disconnected). Therefore, when the above codes are set, the short spring may not be released due to the damaged connector even when the connectors are 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: B-111 SRS-ECU connector.
(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 connector and then reconnect them.
(3)Connect the negative auxiliary battery terminal.
(4)After erasing the diagnosis code memory, check the diagnosis code again.
(5)Disconnect the negative auxiliary battery terminal.

Q. Is diagnosis code B1440 set?
Go to Step 3
The procedure is complete. It is assumed that diagnosis code B1440 set as connector B-111 was engaged improperly.

STEP 3. Connector lock check: B-111 SRS-ECU connector, B-29 intermediate connector and C-03 curtain air bag module (RH) connector.
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative auxiliary battery terminal is connected, disconnect it.

(2)Disconnect connectors B-111 and B-29 and then reconnect them. Slide the outer hosing of intermediate connector B-29 in the arrow direction shown.

(3)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)Connect the negative auxiliary battery terminal.
(5)After erasing the diagnosis code memory, check the diagnosis code again.
(6)Disconnect the negative auxiliary battery terminal.

Q. Is diagnosis code B1440 set?

Go to Step 4

The procedure is complete. It is assumed that diagnosis code B1440 set as connector B-111, B-29 or C-03 was engaged improperly.

STEP 4. 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.

(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.

Q. Is diagnosis code B1440 set?

Go to Step 5

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

STEP 5. Resistance measurement at the B-111 SRS-ECU connector.
(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.

(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)
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-111 wiring harness side connector terminal No. 55 and No. 56.
OK: No continuity

Q. Is the check result normal?

Go to Step 6

Repair the harness wires between SRS-ECU connector B-111 (terminal No.55 and 56) and curtain air bag module (RH) connector C-03 (terminal No.2 and 1).

STEP 6. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1440 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).