Code No. B1570: Manual Cut Off Switch Malfunction
Code No. B1571: Manual Cut Off Switch Circuit Open (For Normal/Close Terminal)
Code No. B1572: Manual Cut Off Switch Circuit (Earth Side) Shorted (For Normal/Close Terminal)
Code No. B1573: Manual Cut Off Switch Circuit (Power Supply Side) Shorted (For Normal/Close Terminal)
Code No. B1574: Manual Cut Off Switch Circuit Open (For Normal/Open Terminal)
Code No. B1575: Manual Cut Off Switch Circuit (Earth Side) Shorted (For Normal/Open Terminal)
Code No. B1576: Manual Cut Off Switch Circuit (Power Supply Side) Shorted (For Normal/Open Terminal)
Code No. B1577: Manual Cut Off Switch Circuit Open (For Common Terminal)
Code No. B1578: Manual Cut Off Switch Circuit (Earth Side) Shorted (For Common Terminal)
Code No. B1579: Manual Cut Off Switch Circuit (Power Supply Side) Shorted (For Common Terminal)
Code No. B1581: Incorrect Manual Cut Off Switch












caution If diagnosis code B1570, B1571, B1572, B1573, B1574, B1575, B1576, B1577, B1578, B1579 or B1581 are set in the SRS-ECU, always diagnose the CAN bus lines.

OPERATION



DIAGNOSIS CODE SET CONDITIONS




Code No.
 Symptom
B1570
 Malfunction of passenger’s air bag cut off switch
B1571
 Malfunction of the Normal/Close terminal or open circuit in its harness
B1572
 Short to body earth in the Normal/Close terminal harness
B1573
 Short to the power supply in the Normal/Close terminal harness
B1574
 Malfunction of the Normal/Open terminal or open circuit in its harness
B1575
 Short to body earth in the Normal/Open terminal harness
B1576
 Short to the power supply in the Normal/Open terminal harness
B1577
 Malfunction of the common terminal or open circuit in its harness
B1578
 Short to body earth in the common terminal harness
B1579
 Short to the power supply in the common terminal harness
B1581
 Detection of passenger’s air bag cut off switch misconnection

PROBABLE CAUSES



  • Malfunction of the passenger’s air bag cut off switch

  • Damaged wiring harnesses or connectors

  • Malfunction of the SRS-ECU

DIAGNOSIS PROCEDURE

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

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54D, Diagnosis-Can Bus Diagnostic Chart ).

STEP 2. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition: "LOCK" (OFF) position to "ON"
(3)On completion, check that the diagnosis code is not reset.

Q. Is the diagnosis code set?
Go to Step 3.
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

STEP 3. Connector check: D-12 passenger’s air bag cut off switch connector

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Check the passenger’s air bag cut off switch.
Refer to .

Q. Is the check result normal?
Go to Step 5.
Replace passenger’s air bag cut off switch (Refer to .)

STEP 5. Check the passenger’s air bag cut off switch circuit. Resistance measurement at SRS-ECU connector D-24.
(1)Disconnect the negative battery terminal.
(2)Disconnect SRS-ECU connector D-24.

(3)Switch the passenger’s air bag cut off switch to air bag ON side.
(4)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Measure the resistance between terminal 29 and terminal 35.
OK: Continuity (Less than 2 Ω)

(5)Switch the passenger’s air bag cut off switch to air bag OFF side.
(6)
caution Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
Measure the resistance between terminal 41 and terminal 35.
OK: Continuity (Less than 2 Ω)

Q. Is the check result normal?

Go to Step 6.

Repair the harness wires between SRS-ECU connector D-24 (terminal No.29, 35 and 41) and passenger’s air bag cut off switch connector D-12 (terminal No.2, 1 and 4).

STEP 6. Check whether the diagnosis code is reset.

Q. Is diagnosis code B1570, B1571, B1572, B1573, B1574, B1575, B1576, B1577, B1578, B1579 or B1581 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).