DTC P0117 (Flash Code 23) Engine Coolant Temperature Sensor Circuit Low (RZ4E-TC)

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Diagnostic system check-engine controls".

2. Engine coolant temperature sensor signal voltage check

1) 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 Engine coolant temperature sensor signal output voltage check.

No

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(RZ4E-TC) intermittent conditions of engine".

3. Engine coolant temperature sensor signal output voltage check

1) Turn OFF the ignition switch.

2) Disconnect the engine coolant temperature sensor harness connector (E20).

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) Turn ON the ignition switch.

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: 4.5 V

Yes

Replace the engine coolant temperature sensor.

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) engine coolant temperature sensor removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) engine coolant temperature sensor installation".

=>Go to Repair verification.

No

=>Go to Inspection for short to ground in engine coolant temperature sensor signal circuit.

4. Inspection for short to ground in engine coolant temperature sensor signal circuit

1) Inspect the signal circuit between the ECM (pin 3 of E4) and the engine coolant temperature sensor (pin 2 of E20) 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 ECM harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

5. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pins 3 and 28 of 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

=>Go to ECM replacement.

No

Repair the connections as necessary.

=>Go to Repair verification.

6. ECM replacement

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

=>Go to Repair verification.

7. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds 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.