Code No.B1451: Curtain air bag squib (LH) open-circuited
| caution |
If diagnosis code B1451 is set in the SRS-ECU, always
diagnose the CAN main bus line.
|
OPERATION
The SRS-ECU judges how severe a collision is by
detecting signals from the left and right side impact sensors. If the impact
is over a predetermined level, the SRS-ECU sends an ignition signal. At this
time, if the side-airbag safing G-sensor is on, the curtain air bag module
will deploy.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if there
is abnormal resistance between the input terminals of the curtain air bag
module (LH) (squib).
PROBABLE CAUSES
- Improper connector contact
- Open circuit in the curtain air bag module (LH) (squib) circuit
- Malfunction of the SRS-ECU
|
|
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 (LH).
|
|
|
(1)Disconnect the negative battery terminal.
|
|
(2)Disconnect curtain air bag module (LH)
connector E-08. 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-08 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 B1451 set?
Go to Step 4.
Replace the curtain air bag module
(LH) (Refer to ).
|
|
|
STEP 4. Resistance measurement between SRS-ECU connector D-25 (terminal
No.5 and 6) and the curtain air bag module (LH) connector E-08 (terminal
No.2 and 1).
|
|
|
(1)Disconnect the negative battery terminal.
|
|
(2)Disconnect SRS-ECU connector D-25 and
curtain air bag module (LH) connector E-08. For connector E-08, 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 E-08 harness side connector to
special tool resistor harness (MB991884).
(4)
| 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 the following terminals.
- SRS-ECU connector D-25 (terminal No.5) and special tool terminal
No.1
- SRS-ECU connector D-2 (terminal No.6) and special tool terminal
No.2
OK: Continuity (Less than 2 Ω)
Q.
Are the check results normal?
Go to Step 5.
Repair the harness wire between
SRS-ECU connector D-25 (terminal No.5 and 6) and curtain air bag module
(LH) connector E-08 (terminal No.2 and 1).
|
|
|
STEP 5. Check whether the diagnosis code is reset.
|
|
|
Q.
Is diagnosis code No.B1451 set?
|
|
|
Replace the SRS-ECU (Refer to ).
|
|
|
|
|
|
An
intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
|
|
|
|