1) Connect the scan tool.
2) Power up the scan tool. Does the scan tool power up?
Yes
=>Go to SRS control unit communication verification.
No
Go to Scan tool does not power up.
Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Scan tool does not power up".
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".
1) Verify that communication can be established with the SRS control unit using the scan tool. Can communication with the SRS control unit be established?
Yes
Go to Intermittent conditions of SRS control.
Refer to "209.Restraints 22D.Symptom Intermittent conditions of SRS control".
No
=>Go to Central gateway control unit communication verification.
1) Verify communication with the central gateway control unit using the scan tool. Can communication with the central gateway control unit be established?
Yes
=>Go to Chassis CAN communication circuit communication verification.
No
Go to Lost communication with the central gateway control unit.
1) Verify that communication can be established with the following control modules using a scan tool. Can communication with all the control modules be established?
Yes
No
Go to Chassis CAN communication circuit inspection.
Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) chassis CAN communication circuit inspection".
1) Turn OFF the ignition switch for 15 seconds or more.
2) Inspect the SRS (IG1) 10A fuse for a blowout. Is the result normal?
Yes
=>Go to SRS control unit harness connector inspection.
No
Replace the fuse. If the fuse blows out again, repair the short to ground in the circuits relating to the SRS (IG1) 10A fuse.
1) Inspect for poor connections at the SRS control unit harness connector (pins 10 and 18 of B8). Is the result normal?
Refer to "LHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Inspection for open circuit in SRS control unit power supply circuit.
No
Repair the connections as necessary.
1) Disconnect the SRS control unit harness connector (B8).
2) Connect a test lamp between the ignition power supply circuit (pin 10 of B8) and the body ground.
Refer to "LHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
3) Turn ON the ignition switch. Does the test lamp illuminate?
Yes
=>Go to Inspection for open circuit in SRS control unit ground circuit.
No
Repair the open circuit or high resistance in the ignition power supply circuit between the SRS (IG1) 10A fuse and the SRS control unit (pin 10 of B8).
1) Connect a test lamp between the ignition power supply circuit and the ground circuit of the SRS control unit harness connector (pins 10 and 18 of B8).
Refer to "LHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD SRS airbag (Driver/Passenger)" in the ETM (wiring diagram). (Open using the ETM viewer.).
2) Turn ON the ignition switch. Does the test lamp illuminate?
Yes
=>Go to Inspection for open circuit and short circuit in CAN communication circuit.
No
Repair the open circuit or high resistance in the ground circuit between the SRS control unit (pin 18 of B8) and the body ground.
1) Inspect the CAN communication circuit between the SRS control unit (pins 16 and 17 of B8) and the central gateway control unit (pins 1 and 2 of B41) for the following. Is the result normal?
Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to SRS control unit replacement.
No
Repair the circuit as necessary.
Note
Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit removal".
Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit installation".
Refer to "8.Restraints 8Z.Seat Belt and SRS Airbag Electrical Control SRS control unit setting".
Procedure completion
1) Securely connect the disconnected harness connectors.
2) Turn OFF the ignition switch for 15 seconds or more.
3) Connect the scan tool.
4) Turn ON the ignition switch.
5) Verify that communication can be established with the SRS control unit using the scan tool. Can communication with the SRS control unit be established?
Yes
The system is normal.
No