Code No.B1462: Seat belt pre-tensioner squib (RH) (earth side) short-circuited












caution If diagnosis code B1462 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 earth in the seat belt pre-tensioner (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 seat belt pre-tensioner (RH).
(1)Disconnect the negative battery terminal.

(2)Pull up the lock lever shown in the figure to the direction of the arrow, and release the lock. Then, disconnect seat belt pre-tensioner (RH) connector E-30.

(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).
(4)Connect special tool MB991866 to the E-30 harness side connector.
(5)Connect the negative battery terminal.
(6)Erase the diagnosis code from memory, and then check the diagnosis code.

Q. Is diagnosis code B1462 set?

Go to Step 4.

Replace the seat belt with pre-tensioner (RH) (Refer to ).

STEP 4. Check the seat belt pre-tensioner (RH) circuit. Resistance measurement at the SRS-ECU connector D-23.
(1)Disconnect the negative battery terminal.
(2)Disconnect SRS-ECU connector D-23.

(3)
danger To prevent the seat belt pre-tensioner from deploying unintentionally, disconnect the seat belt pre-tensioner (RH) connector E-30 to short the squib circuit.
Pull up the lock lever shown in the figure to the direction of the arrow, and release the lock. Then, disconnect seat belt pre-tensioner (RH) connector E-30.

(4)
caution Insert an insulator such as a cable tie to a depth of 4mm or more, otherwise the short spring will not be released.
Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 59, 60 and the short spring to 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 for continuity between D-23 harness side connector terminals 59, 60 and body earth.
OK: Open circuit

Q. Is the check result normal?

Go to Step 5.

Repair the harness wire between SRS-ECU connector D-23 (terminal No. 59 and 60) and seat belt pre-tensioner (RH) connector E-30 (terminal No. 2 and 1).

STEP 5. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1462 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).