B1443

DTC B1443: Curtain Air Bag Module (RH) (Squib) System Fault Power Supply Circuit (Short-Circuited to Power Supply)

Curtain Air Bag Module (RH) (Squib) Circuit:

CAUTION: If DTC B1443 is set in the SRS-ECU, always diagnose the CAN main bus line.

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 curtain air bag module to inflate the curtain air bag.

DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the curtain air bag module (RH) (squib).

TROUBLESHOOTING HINTS
- Damaged wiring harnesses or connectors
- Short to the power supply in the curtain air bag 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
- MB991884: 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."
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES: Go to Step 2.

NO: Repair the CAN bus line (Refer to Information Bus, Diagnosis).

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 How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).

STEP 3. Check the curtain air bag module (RH). (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.







2. Disconnect curtain air bag module (RH) connector D-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 MB991865 to special tool MB991884.
4. Connect special tool MB991884 to the D-08 harness side connector.
5. Connect the negative battery terminal.
6. Erase diagnostic trouble code memory, and then check the diagnostic trouble code.

Q: Is DTC B1443 set?

YES: Go to Step 4.

NO: Replace the curtain air bag module (RH). Then go to Step 6.

STEP 4. Check the curtain air bag module (RH) circuit. Measure the voltage at the SRS-ECU connector C-124.




1. Disconnect SRS-ECU connector C-124.







2. Disconnect curtain air bag module (RH) connector D-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. 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 61, 62 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 B1443 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.61 and 62) and curtain air bag module (RH) connector D-08 (terminal No.1 and 2).

Q: Are the harness wires between SRS-ECU connector C-124 (terminal No.61 and 62) and curtain air bag module (RH) connector D-08 (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 curtain air bag module (RH) connector D-08. 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 B1443 set?

YES: Return to Step 1.

NO: The procedure is complete.