Code No.B1410 Passenger’s (front) air bag module (squib) system (short circuit between squib circuit terminals)


caution
  • If the diagnosis code B1410 is set to SRS-ECU, be sure to diagnose the CAN bus line.
  • Follow the diagnosis procedure below. If diagnosis code B1410 is set, check squib side circuit.

OPERATION



TROUBLE JUDGEMENT



PROBABLE CAUSES



  • Damaged short spring *
  • Short circuit between terminals of passenger’s (front) air bag module (squib) circuit
  • Damaged connector(s)
  • Malfunction of SRS-ECU
note *: The squib circuit connectors integrate a short spring (which prevents the air bags from being unintentionally deployed because of static electricity by shorting the positive wire to the earth wire in the squib circuit when the connectors are disconnected). Therefore, when the above codes are set, the short spring may not be released due to the damaged connector even when the connectors are connected.

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).

STEP 2. Check whether the diagnosis code is reset.
(1)Connect the negative battery terminal.
(2)After erasing the diagnosis code memory, check the diagnosis code again.
(3)Disconnect the negative battery terminal.

Q. Is the diagnosis code No. B1410 set?
Go to Step 3.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

STEP 3. Connector check: passenger’s (front) air bag module, SRS-ECU.
(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever. After disconnecting the SRS-ECU connector, connect it again.

(3)Use the flat-tipped screwdriver to pull out the locking button of wiring harness side connector, and release the lock, connect the connector again.
(4)Connect the negative battery terminal.
(5)After erasing the diagnosis code memory, check the diagnosis code again.
(6)Disconnect the negative battery terminal.

Q. Is the diagnosis code No. B1410 set?

Go to Step 4.

Replace the connector concerned.

STEP 4. Diagnosis check by dummy resistor connection.
(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)Use the flat-tipped screwdriver to pull out the locking button of wiring harness side connector, and release the lock.

(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991866).
(4)
caution Do not insert a probe directly into the terminal from the connector front side as the connector contact pressure may be weakened.
Insert the resistor harness probe from the back of passenger’s (front) air bag module harness side connector ASQ+, ASQ- line.
(5)Connect the negative battery terminal.
(6)
caution Do not insert a probe directly into the terminal from the connector front side as the connector contact pressure may be weakened.
After erasing the diagnosis code memory, check the diagnosis code again.
(7)Disconnect the negative battery terminal.

Q. Is the diagnosis code No. B1410 set?

Go to Step 5.

Replace the passenger’s (front) air bag module (Refer to ).

STEP 5. Resistance measurement at the SRS-ECU connector.
(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.

(3)
danger To release the connector short spring in the following operations, disconnect this harness side connector, and keep the squib circuit shorted.
Use the flat-tipped screwdriver to pull out the locking button of wiring harness side connector, and release the lock.

(4)
caution The short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm or more.
Insert an insulator (width: 3 mm, thickness: 0.5 mm) such as cable tie between the ASQ+, ASQ- line, and then release the short spring.
(5)Take the measurements below at the harness side connector.

  • Continuity between the ASQ+, ASQ- line
OK: No continuity

Q. Is the check result normal?

Go to Step 6.

Repair the wiring harnesses ASQ+, ASQ- line between the passenger’s (front) air bag module connector and the SRS-ECU connector.

STEP 6. Check whether the diagnosis code is reset.

Q. Is the diagnosis code No. B1410 set?
Replace SRS-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).