Note
Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Diagnostic system check-engine controls".
1) Inspect the engine coolant for the following. Is the result normal?
Refer to "1.Engine 1D.Cooling(4JJ3 without DPD) coolant inspection".
Yes
=>Go to Individual harness connector inspection.
No
Repair or replace as necessary.
1) Inspect for poor connections at the engine coolant temperature sensor harness connector (pins 1 and 2 of E20). Is the connection status normal?
2) Inspect for poor connections at the ECM harness connector (pin 31 of E1 and pin 18 of E3). Is the connection status normal?
Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
3) Are all of the results normal?
Yes
=>Go to Inspection for high resistance in engine coolant temperature sensor circuit.
No
Repair the connections as necessary.
1) Inspect the circuit between the ECM (pin 31 of E1 and pin 18 of E3) and the engine coolant temperature sensor (pins 1 and 2 of E20) for high resistance. Is the result normal?
Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
Replace the engine coolant temperature sensor.
Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) engine coolant temperature sensor removal".
Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) engine coolant temperature sensor installation".
No
Repair the circuit as necessary.
1) Clear the DTC with a scan tool.
2) Turn OFF the ignition switch for 1 minute or more.
3) Start the engine.
4) Operate the vehicle under the conditions for running the DTC.
5) Observe the DTC information with a scan tool.