MSB is released for this page as follows:
Release DateSubjectMSB No.
2008-10-20SIDE-AIRBAG MODULE HARNESSMSB-08E52-503

Code No.B1421: Side-airbag module (RH) (squib) system (open-circuited in the squib circuit)





caution If diagnosis code B1421 is set in the combination meter, always diagnose the CAN bus lines.

OPERATION




DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set if there is abnormal resistance between the input terminals of the side-airbag module (RH) (squib).

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics.


warning Since the radiator fan rotates during CAN bus line diagnostics, make sure that no one is servicing the engine compartment before diagnosing the CAN bus line. Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the time-out of the engine-ECU, and activates the radiator fan to prevent overheating as fail-safe.
Use the M.U.T.-III to check the CAN bus lines.

Q. Is the CAN bus line found to be normal?

Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C, Troubleshooting - Can Bus Diagnosis Table ).

STEP 2. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch to "ON" position.
(3)Check if the diagnosis code is set.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the diagnosis code set?

Go to Step 3.
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

STEP 3. Check the side-airbag module (RH) (M.U.T.-III diagnosis code).


(1)Disconnect the negative battery terminal.

(2)Disconnect the side-airbag module (RH) connector C-04.

(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 resistor harness (MB991866) into the C-04 harness side connector by backprobing.
(5)Connect the negative battery terminal.
(6)Erase the diagnosis code memory, and check the diagnosis code.

Q. Is diagnosis code B1421 set?

Go to Step 4.

Replace the side-airbag module (RH) (Refer to ).

STEP 4. Resistance measurement between the SRS-ECU connector B-109 (terminal No.12 and 13) and the side-airbag module (RH) connector C-04 (terminal No.1 and 2).




(1)Disconnect SRS-ECU connector B-109 and side-airbag module (RH) connector C-04.

(2)
caution Do not insert a test probe into the C-04 connector terminal from its front side directly as the connector contact pressure may be weakened.
Resistance measurement between the following terminals.

  • SRS-ECU connector B-109 (terminal No.12) and the side-airbag module (RH) connector C-04 (terminal No.1)
  • SRS-ECU connector B-109 (terminal No.13) and the side-airbag module (RH) connector C-04 (terminal No.2)

Q. Are the check results normal?

Go to Step 5.

Repair the harness wires between SRS-ECU connector B-109 (terminal No.12 and 13) and side-airbag module (RH) connector C-04 (terminal No.1 and 2).

STEP 5. Check whether the diagnosis code is reset.


Q. Is diagnosis code B1421 set?

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





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