Code No.B1422: Side-airbag module (RH) (squib) system (short-circuited to the earth)














OPERATION




TROUBLE JUDGEMENT




PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Short to the earth in the side-airbag module (RH) (squib) harness
  • Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE


STEP 1. Diagnosis check by dummy resistor connection.


(1)Check that the negative auxiliary battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)Disconnect the C-29 side-airbag module (RH) connector. When disconnecting C-29 connector, unlock the connector by sliding the locking button to the direction of the arrow as shown in the figure, and then disconnect the connector.

(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).
(4)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Insert special tool (MB991866) into the harness side connector C-29 by backprobing.
(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 B1422 set?

Go to Step 2

Replace the front seatback assembly (RH) (Refer to ).

STEP 2. 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 the connector short spring in the following operations, disconnect this side-airbag module connector, and keep the squib circuit shorted.
Disconnect the C-29 side-airbag module (RH) connector. When disconnecting C-29 connector, unlock the connector by sliding the locking button to the direction of the arrow as shown in the figure, and then disconnect the connector.

(4)
caution The short spring may not be released due to the insufficient insertion, thus insert for 4 mm or more.
Insert the insulator (width: 3 mm, thickness: 0.5 mm) such as cable tie between the terminals Nos. 53 and 54, and then 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.
Take the measurements below at the B-111 harness side connector.

  • Continuity between terminal No. 53/54 and body earth
OK: No continuity

Q. Is the check result normal?

Go to Step 3

Repair the harness wires between B-111 SRS-ECU connector (terminal No.53 and 54) and C-29 side-airbag module (RH) connector (terminal No.1 and 2).

STEP 3. Check whether the diagnosis code is reset.


Q. Is diagnosis code B1422 set?

Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).