B1423

DTC B1423: Side-Airbag Module (RH) (Squib) System Fault Power Supply Circuit (Short-Circuited to Power Supply)

Side-Airbag Module (RH) (Squib) Circuit:

CAUTION: If DTC B1423 is set in the combination meter, always diagnose the CAN bus lines.

CIRCUIT 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 SRS side-airbag will inflate.
- The ignition signal is input to the side-airbag module to inflate the side-airbag.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the side-airbag module (RH) (squib).

TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Short to the power supply in the side-airbag module (RH) (squib) harness
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
- MB991865: Dummy resistor
- MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.






CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool." Scan Tool Connecting
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES : Go to Step 2

NO : Repair the CAN bus lines (Refer to Controller Area Network (CAN), Diagnosis-Can Bus Diagnostic Chart).

STEP 2. Recheck for diagnostic trouble code.






Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.

STEP 3. Check the side-airbag module (RH). (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.




2. Disconnect the side-airbag module (RH) connector D-28.




3. Connect special tool MB991865 to special tool MB991866.

CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into the D-28 harness side connector by backprobing.
5. Connect the negative battery terminal.
6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is DTC B1423 set?

YES : Go to Step 4.

NO : Replace the seatback frame of the front seat (RH) (Refer to Interior, Front Seat). Then go to Step 5.

STEP 4. Check the side-airbag module (RH) circuit. Measure the voltage at the SRS-ECU connector C-124.




1. Disconnect SRS-ECU connector C-124.






DANGER: To prevent the air bag from deploying unintentionally, disconnect the side-airbag module (RH) connector D-28 to short the squib circuit.

2. Disconnect side-airbag module (RH) connector D-28.
3. Turn the ignition switch to the "ON" position.






CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Measure the voltage between C-124 harness side connector terminals 57 and 58 and body ground.

Voltage should measure 0 volt.

Q: Is the measured voltage 0 volt?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1423 sets, replace the SRS-ECU. Then go to Step 6.

NO : Go to Step 5.

STEP 5. Check the harness wires for short circuit to power supply between SRS-ECU connector C-124 (terminal No.57 and 58) and side-airbag module (RH) connector D-28 (terminal No.1 and 2).






Q: Are the harness wires between SRS-ECU connector C-124 (terminal No.57 and 58) and side-airbag module (RH) connector D-28 (terminal No.1 and 2) in good condition?

YES : Go to Step 6.

NO : Replace the harness wires between SRS-ECU connector C-124 and side-airbag module (RH) connector D-28. Then go to Step 6.

STEP 6. Recheck for diagnostic trouble code.






Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1423 set?

YES : Return to Step 1.

NO : The procedure is complete.