Code No.B1443: Curtain air bag squib (RH) (power supply side) short-circuited

caution

If diagnosis code B1443 is set in the SRS-ECU, always diagnose the CAN main bus line.

OPERATION

DIAGNOSIS CODE SET CONDITIONS

PROBABLE CAUSES

Damaged wiring harnesses or connectors
Short to the power supply in the curtain air bag module (RH) (squib) harness
Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

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

Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus line (Refer to GROUP 54D, Diagnosis ).

STEP 2. Check whether the diagnosis code is reset.

Check again if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Ignition: "LOCK" (OFF) position to "ON"

(3)On completion, check that the diagnosis code is not reset.

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 curtain air bag module (RH).

(1)Disconnect the negative battery terminal.

(2)Disconnect curtain air bag module (RH) connector E-04. Use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it toward you in two stages, and then disconnect the connector.

(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
(4)Connect special tool (MB991884) to the E-04 harness side connector.
(5)Connect the negative battery terminal.
(6)Erase the diagnosis code from memory, and check the diagnosis code.

Q. Is diagnosis code B1443 set?

Go to Step 4.

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

STEP 4. Check the curtain air bag module circuit. Voltage measurement at the SRS-ECU connector D-23.

(1)Disconnect the negative battery terminal.

(2)Disconnect SRS-ECU connector D-23.

danger

To prevent the air bag from deploying unintentionally, disconnect the curtain air bag module (RH) connector E-04 to short the squib circuit.

(3)Disconnect curtain air bag module (RH) connector E-04. Use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it toward you in two stages, and then disconnect the connector.

(4)

caution

Insert an insulator such as a cable tie to a depth of 4 mm or more, otherwise the short spring will not be released.

Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 61, 62 and the short spring to release the short spring.
(5)Connect the negative battery terminal.
(6)Turn the ignition switch to the "ON" position.
(7)

caution

Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.

Measure the voltage between D-23 harness side connector terminals 61, 62 and body earth.
OK: 0 V

Q. Is the check result normal?

Go to Step 5.

Repair the harness wire between SRS-ECU connector D-23 (terminal No.61 and 62) and curtain air bag module (RH) connector E-04 (terminal No.1 and 2).

STEP 5. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1443 set?

	Replace the SRS-ECU (Refer to ).

	An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).