CHECK CONNECTION OF CONNECTORS
CHECK FRONT AIRBAG SENSOR LH CIRCUIT
CHECK INSTRUMENT PANEL WIRE ASSEMBLY (CENTER AIRBAG SENSOR - ENGINE ROOM MAIN WIRE)
DTC B1607/84 Lost Communication with Front Satellite Sensor Bus LH |
DTC B1608/84 Front Satellite Sensor Bus LH Initialization Incomplete |
DTC B1617/84 Lost Communication with Front Airbag Sensor LH |
DTC B1618/84 Front Airbag Sensor LH Initialization Incomplete |
DESCRIPTION
The front airbag sensor LH circuit consists of the center airbag sensor assembly and front airbag sensor LH.The front airbag sensor LH detects impacts to the vehicle and sends signals to the center airbag sensor assembly to determine if the airbag should be deployed.
DTC B1607/84, B1608/84, B1617/84 or B1618/84 is recorded when a malfunction is detected in the front airbag sensor LH circuit.
DTC Code | Detection Condition | Trouble Area |
B1607/84 B1608/84 B1617/84 B1618/84 | When one of following conditions is met:
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WIRING DIAGRAM

INSPECTION PROCEDURE
1.CHECK CONNECTION OF CONNECTORS |
Turn the ignition switch off.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
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.
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OK | |
2.CHECK CONNECTORS |
Disconnect the connectors from the center airbag sensor assembly and front airbag sensor LH.
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.
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OK | |
3.CHECK FRONT AIRBAG SENSOR LH CIRCUIT |

Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
Tester Connection Switch Condition Specified Condition A12-2 (+SL) - Body ground Ignition switch ON Below 1 V A12-1 (-SL) - Body ground Ignition switch ON Below 1 V
Turn the ignition switch off.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.
- NOTICE:
- Do not forcibly insert a service wire into the terminals of the connector when connecting the wire.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition A12-2 (+SL) - A12-1 (-SL) Always Below 1 Ω
Disconnect the service wire from connector B.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition A12-2 (+SL) - A12-1 (-SL) Always 1 MΩ or higher A12-2 (+SL) - Body ground Always 1 MΩ or higher A12-1 (-SL) - Body ground Always 1 MΩ or higher
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OK | |
4.CHECK FRONT AIRBAG SENSOR LH |
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Connect the connectors to the center airbag sensor assembly.
Interchange the front airbag sensor LH with RH and connect the connectors to them.
Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
Turn the ignition switch to ON, and wait for at least 60 seconds.
Clear the DTCs stored in the memory (YARIS_NCP93 RM000000XFE0D2X.html).
Turn the ignition switch off.
Turn the ignition switch to ON, and wait for at least 60 seconds.
Check for DTCs (YARIS_NCP93 RM000000XFE0D2X.html).
Result Result Proceed to DTC B1602/83, B1603/83, B1612/83, B1613/83, B1607/84, B1608/84, B1617/84 and B1618/84 are not output A DTC B1602/83, B1603/83, B1612/83 or B1613/83 is output B DTC B1607/84, B1608/84, B1617/84 or B1618/84 is output C - HINT:
- Codes other than DTC B1602, B1603, B1612, B1613, B1608, B1608, B1617, B1618, 83 and 84 may be output at this time, but they are not related to this check.
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C | ||
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5.CHECK INSTRUMENT PANEL WIRE ASSEMBLY (CENTER AIRBAG SENSOR - ENGINE ROOM MAIN WIRE) |

Disconnect the instrument panel wire connector from the engine room main wire.
Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
Turn the ignition switch to ON.
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
Turn the ignition switch off.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Using a service wire, connect terminals 30 (+SL) and 28 (-SL) of connector B.
- NOTICE:
- Do not forcibly insert a service wire into the terminals of the connector when connecting the wire.
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
Disconnect the service wire from connector B.
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
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OK | ||
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