1) Connect the scan tool. Does the scan tool power up?
Yes
=>Go to Scan tool communication verification.
No
Go to Scan tool does not power up.
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".
1) Check the communication status with the ECM using the scan tool. Can communication with the ECM be established?
Yes
Go to Intermittent conditions of engine.
Refer to "202.Engine 15D.Symptom(RZ4E-TC) intermittent conditions of engine".
No
1) Inspect for poor connections at the DLC (pins 6 and 14 of C19). Is the connection status normal?
Refer to "RHD DLC" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD DLC" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to ECM harness connector inspection.
No
Repair the connections as necessary.
1) Inspect for poor connections at the ECM harness connectors (C7, E4). Is the connection status normal?
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
No
Repair the connections as necessary.
1) Inspect the following fuses for a blowout. Is the result normal?
Yes
=>Go to Inspection for open circuit in ignition power supply circuit.
No
Replace the fuse as necessary. If the fuse blows out again, repair the short to ground in the circuit relating to each fuse.
1) Turn OFF the ignition switch.
2) Disconnect the ECM harness connector (C7).
3) Connect a test lamp between the ignition power supply circuit (pin 24 of C7) and the body ground.
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
4) Turn ON the ignition switch. Does the test lamp illuminate?
Yes
=>Go to ECM ground inspection.
No
Repair the open circuit in the ignition power supply circuit between the ENGINE(IG1) 5A fuse and the ECM (pin 24 of C7).
1) Inspect the ECM ground section for corrosion or improper installation. Is the result normal?
Caution
Yes
=>Go to ECM main relay inspection.
No
Repair the ground point as necessary.
1) Turn OFF the ignition switch.
2) Connect the ECM harness connector (C7).
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
3) Replace the ECM main relay with a known good relay.
4) Turn ON the ignition switch.
5) Check the communication status with the ECM using the scan tool. Can communication with the ECM be established?
Yes
Replace the ECM main relay.
No
=>Go to Inspection for open circuit in ECM main relay voltage supply circuit.
1) Turn OFF the ignition switch.
2) Remove the ECM main relay.
3) Connect a test lamp between the ECM main relay voltage supply circuit (pin 1 of Fuse and Relay Box (Engine Compartment) ECM MAIN) and the body ground.
4) Connect a test lamp between the ECM main relay control circuit (pin 3 of Fuse and Relay Box (Engine Compartment) ECM MAIN) and the body ground.
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
5) Turn ON the ignition switch. Do both the test lamps illuminate?
Yes
=>Go to Inspection for open circuit in ECM main relay circuit.
No
Repair the circuit as necessary.
1) Install the ECM main relay.
2) While checking the operation sounds of the ECM main relay, turn the ignition switch ON/OFF. Is an operation sound of the ECM main relay heard?
Note
Yes
=>Go to Inspection for open circuit in ECM main relay power supply circuit.
No
=>Go to Inspection for open circuit in ECM main relay ground circuit.
1) Inspect the ground circuit between the ECM main relay (pin 4 of Fuse and Relay Box (Engine Compartment) ECM MAIN) and the ground terminal for the following. Is the result normal?
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Inspection for open circuit in ECM main relay power supply circuit.
No
Repair the circuit as necessary.
1) Inspect the battery power supply circuit between the ECM (pins 2 and 5 of C7) and the ECM main relay (pin 2 of Fuse and Relay Box (Engine Compartment) ECM MAIN) for the following. Is the result normal?
Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to CAN circuit resistance check.
No
Repair the circuit as necessary.
1) Connect the ECM harness connector (C7).
2) Turn OFF the ignition switch.
3) Disconnect the scan tool from the DLC (C19) if connected.
4) Measure the resistance between the CAN High circuit and the CAN Low circuit of the DLC (pins 6 and 14 of C19) with a DMM. Is the resistance within the specified range?
Note
Refer to "RHD Controller Area Network (Except 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 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Controller Area Network (Except Central Gateway C/U)" 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.).
Value: 50 to 70 Ω
Yes
=>Go to Inspection for short circuit in CAN circuit.
No
=>Go to Inspection for open circuit and short circuit in CAN circuit.
1) Inspect for poor connections at the ECM harness connector (pins 58 and 78 of C7). Is the connection status normal?
2) Inspect the CAN High circuit and CAN Low circuit between the DLC (pins 6 and 14 of C19) and the ECM (pins 58 and 78 of C7) for the following. Is the result normal?
Refer to "RHD Controller Area Network (Except 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 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Controller Area Network (Except Central Gateway C/U)" 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.).
3) Are all of the results normal?
Yes
No
Repair the circuit as necessary.
1) Inspect the CAN High circuit and CAN Low circuit between the DLC (pins 6 and 14 of C19) and the ECM (pins 58 and 78 of C7) for the following. Is the result normal?
Refer to "RHD Controller Area Network (Except 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 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "LHD Controller Area Network (Except Central Gateway C/U)" 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 "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM removal".
Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM installation".
Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM setting".
Procedure completion
1) Turn OFF the ignition switch.
2) Reconnect all of the removed fuses, relays, and harness connectors.
3) Turn ON the ignition switch.
4) Check the communication status with the ECM using the scan tool. Can communication with the ECM be established?
Yes
The system is normal.
No