Code No.B1609:
Seat belt pre-tensioner (passenger’s side) (squib) system (short-circuit between terminals
of the squib circuit)
OPERATION
The SRS-ECU judges how severe a collision is by detecting signals from the front impact
sensors and the front air bag analogue G-sensor. If the impact is over a predetermined level,
the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is
on, the seat belt pre-tensioner will deploy.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if one seat belt pre-tensioner (passenger’s side)
squib wire shorted to the other.
PROBABLE CAUSES
Improper engaged connector or defective short spring*
Short circuit between the seat belt pre-tensioner (passenger’s side) (squib)
circuit terminals
Damaged connector(s)
Malfunction of the SRS-ECU
note
*: The squib circuit connectors integrate a "short" spring (which prevents the
air bag from deploying unintentionally due to static electricity by shorting the positive wire
to the earth wire in the squib circuit when the connectors are disconnected). Therefore, if
connector C-153 or D-23 <LHD>, D-15 <RHD> is damaged or improperly engaged, the short spring
may not be released when the connector is connected.
(2)Disconnect the connectors C-153 and then reconnect it. (3)Connect the negative battery terminal. (4)Erase the diagnosis code memory, and check the diagnosis code.
Q.
Is diagnosis code B1609 set?
Go to Step 3.
The procedure is complete. It is assumed that diagnosis code B1609 set as connector
C-153 was engaged improperly.
(2)Disconnect the connectors C-153 and then reconnect it.
(3)Disconnect connector D-23 <LHD>, D-15 <RHD> and then reconnect them. Use a flat-tipped
screwdriver to pull out the locking button at the harness side connector. (4)Connect the negative battery terminal. (5)Erase the diagnosis code memory, and check the diagnosis code.
Q.
Is diagnosis code B1609 set?
Go to Step 4.
The procedure is complete. It is assumed that diagnosis code B1609 set as connector
C-153 or D-23 <LHD>, D-15 <RHD> was engaged improperly.
STEP 4. Check the diagnosis code by connecting a dummy resistor. (M.U.T.-III
diagnosis code)
(1)Disconnect the negative battery terminal.
(2)Disconnect seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>,
D-15 <RHD>. Use a flat-tipped screwdriver to pull out the locking button at the harness
side connector, 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 D-23 <LHD>, D-15 <RHD> harness side
connector. (5)Connect the negative battery terminal. (6)Erase diagnosis code memory, and then check the diagnosis code.
Q.
Is diagnosis code B1609 set?
Go to Step 5.
Replace the seat belt with pre-tensioner (passenger’s side) (Refer to ).
STEP 5. Resistance measurement at the SRS-ECU connector C-153.
(1)Disconnect the negative battery terminal.
(2)Disconnect SRS-ECU connector C-153.
(3)
danger
To prevents the seat belt pre-tensioner from deploying unintentionally, disconnect the
seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD>
to short the squib circuit.
Disconnect seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>,
D-15 <RHD>. Use a flat-tipped screwdriver to pull out the locking button at the harness
side connector, and then disconnect the connector.
(4)
caution
Insert an insulator such as a cable tie to a depth of 7 mm or more, otherwise the short
spring will not be released.
Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 5, 6
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.
Resistance measurement between C-153 harness side connector terminals 5 and 6. OK: Open circuit.
Q.
Is the check result normal?
Go to Step 6 .
Repair the harness wires between SRS-ECU connector C-153 (terminal No.5 and 6)
and the seat belt pre-tensioner (passenger’s side) connector D-23 <LHD>, D-15 <RHD>
(terminal No.1 and 2).
STEP 6. Check whether the diagnosis code is reset.
Q.
Is diagnosis code B1609 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
)
Go to Step 2.
Go to Step 3.)
)
)
)
).)
)