Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Diagnostic system check-engine controls".
1) Connect the scan tool.
2) Turn OFF the ignition switch for 1 minute or more.
3) Start the engine.
4) Observe the Engine Coolant Temperature (ECT) Sensor parameter on the scan tool. Is the Engine Coolant Temperature (ECT) Sensor parameter more than or equal to the specified value?
Value: 4.8 V
Yes
=>Go to Engine coolant temperature sensor signal output voltage check.
No
Go to Intermittent conditions of engine.
Refer to "202.Engine 15D.Symptom(4JJ3 without DPD) intermittent conditions of engine".
1) Turn OFF the ignition switch.
2) Disconnect the engine coolant temperature sensor harness connector (E20).
3) Turn ON the ignition switch.
4) Measure the voltage between the engine coolant temperature sensor signal circuit (pin 1 of E20) and the body ground with a DMM.
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.).
Value: 4.5 to 5.5 V
The reading is more than the specified value.
=>Go to Inspection for short to power supply in engine coolant temperature sensor signal circuit.
The reading is within the specified range.
=>Go to Engine coolant temperature sensor signal voltage check using fused jumper wire.
The reading is less than the specified value.
=>Go to Inspection for open circuit in engine coolant temperature sensor signal circuit.
1) Connect a fused jumper wire between the signal circuit and the low reference circuit of the engine coolant temperature sensor (pins 1 and 2 of E20).
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.).
2) Observe the Engine Coolant Temperature (ECT) Sensor parameter on the scan tool. Is the Engine Coolant Temperature (ECT) Sensor parameter less than or equal to the specified value?
Value: 0.1 V
Yes
=>Go to Inspection for short to 5 V reference in engine coolant temperature sensor signal circuit.
No
=>Go to Inspection for open circuit in engine coolant temperature sensor low reference circuit.
1) Inspect the signal circuit between the ECM (pin 31 of E1) and the engine coolant temperature sensor (pin 1 of E20) for a short to the battery power supply circuit or a short to the ignition power supply circuit. Is the result normal?
Note
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
No
Repair the circuit as necessary.
1) Inspect the signal circuit between the ECM (pin 31 of E1) and the engine coolant temperature sensor (pin 1 of E20) for an open circuit or 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
=>Go to ECM harness connector inspection.
No
Repair the circuit as necessary.
1) Inspect the low reference circuit between the ECM (pin 18 of E3) and the engine coolant temperature sensor (pin 2 of E20) for an open circuit or high resistance. Is the result normal?
Caution
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
=>Go to ECM harness connector inspection.
No
Repair the circuit as necessary.
1) Inspect the signal circuit between the ECM (pin 31 of E1) and the engine coolant temperature sensor (pin 1 of E20) for a short to the 5 V reference circuit. 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
=>Go to Engine coolant temperature sensor harness connector inspection.
No
Repair the circuit 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?
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 connections as necessary.
1) 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.).
Yes
No
Repair the connections as necessary.
Note
Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM removal".
Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM installation".
Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM setting".
Procedure completion
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.