1) Connect the scan tool.
2) Check whether the scan tool powers up. Does the scan tool power up?
Yes
=>Go to EHCU communication verification.
No
Go to Scan tool does not power up.
Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) 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) Turn ON the ignition switch.
2) Verify communication with the EHCU using the scan tool. Can communication with the EHCU be established?
Yes
Go to Intermittent conditions of brake.
Refer to "205.Brakes 18D.Symptom intermittent conditions of brake".
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) Inspect the following fuses for a blowout. Is the result normal?
Yes
=>Go to EHCU harness connector inspection.
No
Replace the fuse. If the fuse blows out again, repair the short to ground in the circuit relating to each fuse.
1) Inspect the connection status of the EHCU harness connector terminals (pins 1, 13, 25, 28, and 38 of C13). Is the connection status normal?
Refer to "RHD Electronic Stability Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Electronic Stability Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Inspect the EHCU power supply circuit and ground circuit..
No
Repair the connections as necessary.
1) Turn OFF the ignition switch.
2) Disconnect the EHCU harness connector (C13).
3) Inspect the wire harness for the following. Is the result normal?
Wire harness to be inspected
Inspection items
Refer to "RHD Electronic Stability Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Electronic Stability Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Chassis CAN communication circuit inspection.
No
Repair the circuit as necessary.
1) Inspect the communication circuit between the EHCU (pins 26 and 14 of C13) and the central gateway control unit (pins 1 and 2 of B41) for the following. Is the result normal?
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.).
Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
No
Repair the circuit as necessary.
Note
Refer to "4.Brakes 4Z.Brake Electrical Control EHCU removal".
Refer to "4.Brakes 4Z.Brake Electrical Control EHCU installation".
Refer to "4.Brakes 4Z.Brake Electrical Control EHCU setting".
Procedure completion
1) Securely connect the disconnected harness connectors.
2) Connect the scan tool.
3) Turn ON the ignition switch.
4) Verify communication with the EHCU using the scan tool. Can communication with the EHCU be established?
Yes
The system is normal.
No