Toyota Sienna Service Manual: Short to B+ in Front Passenger Side Squib 2nd
Step Circuit
DTC B1188/56 Short to B+ in Front Passenger Side Squib 2nd
Step Circuit
DESCRIPTION
The front passenger side squib 2nd step circuit consists of the center airbag
sensor assembly and the
front passenger airbag assembly.
The circuit instructs the SRS to deploy when deployment conditions are met.
DTC B1188/56 is recorded when a short to B+ is detected in the front passenger
side squib 2nd step
circuit.
DTC No. |
DTC Detecting Condition |
Trouble Area |
B1188/56 |
- Short circuit in front passenger side squib 2nd step
wire harness (to B+)
- Front passenger side squib 2nd step malfunction
- Center airbag sensor assembly malfunction
|
- Front passenger airbag assembly (Front passenger
side squib 2nd step)
- Center airbag sensor assembly
- Instrument panel wire
|
INSPECTION PROCEDURE
HINT:
- Perform the simulation method by selecting the "check mode"
(signal check) with the intelligent tester
(8).
- After selecting the "check mode" (signal check), perform the
simulation method by wiggling each
connector of the airbag system or driving the vehicle on a city or rough
road
1 CHECK FRONT PASSENGER AIRBAG ASSEMBLY (FRONT PASSENGER SIDE SQUIB 2ND
STEP)

- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Disconnect the connectors from the front passenger
airbag assembly.
- Connect the black wire side of SST (resistance 2.1 Ω) to
the instrument panel wire.
CAUTION:
Never connect a tester to the front passenger airbag
assembly (front passenger side squib 2nd step) for
measurement, as this may lead to a serious injury
due to airbag deployment.
NOTICE:
Do not forcibly insert the SST into the terminals of
the connector when connecting.
Insert the SST straight into the terminals of the
connector.
SST 09843-18060
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Clear the DTCs stored in memory (5).
- Turn the ignition switch to the LOCK position.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Check the DTCs (5).
OK:
DTC B1188/56 is not output.
HINT:
Codes other than DTC B1188/56 may be output at this
time, but they are not related to this check.
Go to step 2

REPLACE FRONT PASSENGER AIRBAG ASSEMBLY
2 CHECK INSTRUMENT PANEL WIRE (FRONT PASSENGER SIDE SQUIB 2ND STEP
CIRCUIT)

- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Disconnect the SST (resistance 2.1 Ω) from the
instrument panel wire.
- Disconnect the connector from the center airbag sensor
assembly.
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position.
- Measure the voltage according to the value(s) in the
table below.
Standard voltage

REPAIR OR REPLACE INSTRUMENT
PANEL
WIRE

3 CHECK CENTER AIRBAG SENSOR ASSEMBLY

- Turn the ignition switch to the LOCK position.
- Disconnect the negative (-) terminal cable from the
battery, and wait for at least 90 seconds.
- Connect the connectors to the front passenger airbag
assembly and the center airbag sensor assembly.
- Connect the negative (-) terminal cable to the battery,
and wait for at least 2 seconds.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Clear the DTCs stored in memory (5).
- Turn the ignition switch to the LOCK position.
- Turn the ignition switch to the ON position, and wait for at
least 60 seconds.
- Check the DTCs (5).
OK:
DTC B1188/56 is not output.
HINT:
Codes other than DTC B1188/56 may be output at this
time, but they are not related to this check.
REPLACE CENTER AIRBAG SENSOR
ASSEMBLY

USE SIMULATION METHOD TO CHECK
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DESCRIPTION
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Other materials:
Manual Up / Down and Auto Down Function does not Operate on
Driver Side
DESCRIPTION
If the manual UP/DOWN function does not operate, no power may be supplied to
the power window
master switch or the power window motor. The power window master switch itself
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WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (P/W)
...
Clearance warning ECU
COMPONENTS
REMOVAL
1. REMOVE FRONT DOOR SCUFF PLATE LH
2. REMOVE COWL SIDE TRIM BOARD LH
3. REMOVE INSTRUMENT PANEL FINISH PANEL SUBASSEMBLY LOWER LH
4. REMOVE NO. 1 INSTRUMENT PANEL SAFETY PAD INSERT SUB-ASSEMBLY
5. REMOVE CLEARANCE WARNING ECU
Disconnect each connector.
&nb ...
Installation
1. INSTALL FRONT PASSENGER AIRBAG ASSEMBLY
Install the front passenger airbag assembly with the
2 screws.
2. INSTALL INSTRUMENT PANEL SUB-ASSEMBLY
3. CONNECT FRONT PASSENGER AIRBAG ASSEMBLY CONNECTOR
Connect the connector to the front passenger airbag
assembly.
...