DTC B1617/84: Lost Communication with Front Airbag Sensor LH; DTC B1618/84: Front Airbag Sensor LH Initialization Incomplete: Procedure

1. Turn the ignition switch off.
2. Turn the ignition switch to ON, and wait for at least 60 seconds.
3. Check for DTCs. Refer to DTC CHECK / CLEAR .

   OK

   DTC B161A/8A is not output.

NG → See step   10 

OK: Go to next step 

1. Turn the ignition switch off.
2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the center airbag sensor assembly and the front airbag sensor LH.

   OK

   The connectors are properly connected.

NG → CONNECT CONNECTORS PROPERLY 

OK: Go to next step 

1. Disconnect the connectors from the center airbag sensor assembly and front airbag sensor LH.
2. Check that the connectors (on the center airbag sensor assembly side and front airbag sensor LH side) are not damaged.

   OK

   The connectors are not deformed or damaged.

NG → REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

Fig 1: Checking Front Airbag Sensor (LH) - Center Airbag Sensor Assembly Circuit Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect the cable to the negative battery terminal, and wait for at least 2 seconds.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A5-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
   A5-1 (-SL) - Body ground	Ignition switch ON	Below 1 V

4. Turn the ignition switch off.
5. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
6. Using a service wire, connect terminals 30 and 28 of connector B.
   NOTE:

   Do not forcibly insert a service wire into the terminals of the connector when connecting the wire.

7. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A5-2 (+SL) - A5-1 (-SL)	Always	Below 1 Ω

8. Disconnect the service wire from connector B.
9. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A5-2 (+SL) - A5-1 (-SL)	Always	1 MΩ or higher
   A5-2 (+SL) - Body ground	Always	1 MΩ or higher
   A5-1 (-SL) - Body ground	Always	1 MΩ or higher

NG → See step   6 

OK: Go to next step 

Fig 2: Checking Front Airbag Sensor LH - Center Airbag Sensor Assembly Circuit

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect the connectors to the center airbag sensor assembly.
2. Interchange the front airbag sensor LH with RH and connect the connectors to them.
3. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.
4. Turn the ignition switch to ON, and wait for at least 60 seconds.
5. Clear the DTCs stored in the memory. Refer to DTC CHECK / CLEAR .
6. Turn the ignition switch off.
7. Turn the ignition switch to ON, and wait for at least 60 seconds.
8. Check for DTCs. Refer to DTC CHECK / CLEAR .
   RESULT
   
   

   Result	Proceed to
   DTC B1617/84 or B1618/84 is output	A
   DTC B1612/83 or B1613/83 is output	B
   DTC B1612/83, B1613/83, B1617/84 and B1618/84 are not output	C

   TEXT IN ILLUSTRATION
   
   

   *1	Front Airbag Sensor RH
   *2	Center Airbag Sensor Assembly

   HINT: 

   DTCs other than B1612, B1613, B1617, B1618, 83 and 84 may be output at this time, but they are not related to this check.

9. Turn the ignition switch off.
10. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
11. Return the front airbag sensor LH and front airbag sensor RH to their original positions and connect the connectors to them.

A → See step   7 

B → See step   8 

C → See step   9 

Fig 3: Checking Instrument Panel Wire (Center Airbag Sensor Assembly - Engine Room Main Wire) Circuit Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the instrument panel wire connector from the engine room main wire.
2. Connect the cable to the negative battery terminal, and wait for at least 2 seconds.
3. Turn the ignition switch to ON.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   AD1-3 (+SL) - Body ground	Ignition switch ON	Below 1 V
   AD1-4 (-SL) - Body ground	Ignition switch ON	Below 1 V

5. Turn the ignition switch off.
6. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.
7. Using a service wire, connect terminals 30 and 28 of connector B.
   NOTE:

   Do not forcibly insert a service wire into the terminals of the connector when connecting the wire.

8. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   AD1-3 (+SL) - AD1-4 (-SL)	Always	Below 1 Ω

9. Disconnect the service wire from connector B.
10. Measure the resistance according to the value(s) in the table below.

    Standard Resistance

    Tester Connection	Condition	Specified Condition
    AD1-3 (+SL) - AD1-4 (-SL)	Always	1 MΩ or higher
    AD1-3 (+SL) - Body ground	Always	1 MΩ or higher
    AD1-4 (-SL) - Body ground	Always	1 MΩ or higher

NG → REPLACE INSTRUMENT PANEL WIRE 

OK → REPLACE ENGINE ROOM MAIN WIRE