DTC B1226:29/B1226:4A/B1226:87/B1226:96 [TWO-STEP DEPLOYMENT CONTROL SYSTEM]


id0802b2027900

System malfunction location

•  B1226:29, B1226:96:Driver-side pressure sensor internal malfunction
•  B1226:4A:Driver-side pressure sensor ID error (assembly incorrect)
•  B1226:87:Signal reception error from driver-side pressure sensor
Detection condition
Warning
•  Detection conditions are for understanding the DTC outline before performing an inspection. Performing an inspection according to only the detection conditions may cause injury due to an operating error, or damage the system. When performing an inspection, always follow the inspection procedure.
•  SAS control module detects a driver-side pressure sensor signal error
•  SAS control module detects a driver-side pressure sensor internal malfunction
•  SAS control module detects a different sensor installed
•  SAS control module detects open circuit between the SAS control module and the driver-side pressure sensor
Fail-safe function
Not applicable
Possible cause
•  Driver-side pressure sensor assembly incorrect
•  Driver-side pressure sensor connector malfunction
•  Open circuit in the wiring harness between the Driver-side pressure sensor and SAS control module
―  SAS control module terminal 1V—driver-side pressure sensor terminal A
―  SAS control module terminal 1T—driver-side pressure sensor terminal B
•  Driver-side pressure sensor malfunction
•  SAS control module malfunction


Diagnostic Procedure

Step

Inspection

Action

1
INSPECT DRIVER-SIDE PRESSURE SENSOR
•  Verify that the driver-side pressure sensor is correctly installed.
•  Is the driver-side pressure sensor correctly installed?
Yes
Go to the next step.
No
Correctly install the driver-side pressure sensor.
Then go to the next step.
2
INSPECT DRIVER-SIDE PRESSURE SENSOR CONNECTOR
Warning
•  Handling the component parts improperly can accidentally operate (deploy) the air bag modules and pre-tensioner seat belts, which may seriously injure you. Read the service warnings/cautions and the workshop manual before handling the air bag system components.
•  Switch the ignition off.
•  Disconnect the negative battery cable and wait for 1 min or more.
•  Remove the driver-side front door trim.
•  Disconnect the driver-side pressure sensor connector.
•  Inspect the driver-side pressure sensor connector. (Corrosion, damage, and disconnected pins)
•  Is there any malfunction of the driver-side pressure sensor connector?
Yes
Replace the malfunctioning part, then go to Step 5.
No
Go to the next step.
3
INSPECT DRIVER-SIDE PRESSURE SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Driver-side pressure sensor and SAS control module connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Driver-side pressure sensor terminal A—SAS control module terminal 1V
―  Driver-side pressure sensor terminal B—SAS control module terminal 1T
Note
•  Inspect for continuity while shaking the wiring harness between the SAS control module and driver-side pressure sensor.
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between SAS control module terminal and driver-side pressure sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Replace the malfunctioning part.
If there is no common connector:
•  Replace the wiring harness which has an open circuit.
Go to Step 5.
4
DETERMINE IF MALFUNCTION CAUSE IS DRIVER-SIDE PRESSURE SENSOR
•  Replace the driver-side pressure sensor.
•  Switch the ignition ON (engine off or on).
•  Clear the DTC for the SAS control module using the M-MDS.
•  Perform the DTC inspection for the SAS control module using the M-MDS.
•  Are the same DTCs present?
Yes
Go to the next step.
No
DTC troubleshooting completed.
5
PERFORM SAS CONTROL MODULE DTC INSPECTION
•  Connect the SAS control module connectors.
•  Reconnect all disconnected connectors.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on).
•  Clear the DTC for the SAS control module using the M-MDS.
•  Perform the DTC inspection for the SAS control module using the M-MDS.
•  Are the same DTCs present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the SAS control module.
No
DTC troubleshooting completed.