DTC P0123 Throttle Position Sensor Circuit High (4JJ3 without DPD)

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Diagnostic system check-engine controls".

2. Intake throttle position sensor signal voltage check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Start the engine.

4) Observe the Intake Throttle Valve Position Sensor parameter on the scan tool. Is the Intake Throttle Valve Position Sensor parameter more than or equal to the specified value?

Value: 4.9 V

Yes

=>Go to Prioritized DTC and intake throttle position sensor signal voltage check.

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 without DPD) intermittent conditions of engine".

3. Prioritized DTC and intake throttle position sensor signal voltage check

1) Observe the DTC information with a scan tool for DTC P0697 being set at the same time.

2) Turn OFF the ignition switch.

3) Disconnect the intake throttle valve harness connector (E25).

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.).

4) Turn ON the ignition switch.

5) Observe the Intake Throttle Valve Position Sensor parameter on the scan tool.

Value: 0.3 V

The reading is more than the specified value.

=>Go to Inspection for short to power supply in intake throttle position sensor signal circuit.

The reading is less than or equal to the specified value and DTC P0697 is set.

Go to DTC P0697 diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0697 Sensor Reference Voltage 3 Circuit".

The reading is less than or equal to the specified value and DTC P0697 is not set.

=>Go to Intake throttle position sensor low reference circuit inspection using test lamp.

4. Intake throttle position sensor low reference circuit inspection using test lamp

1) Connect a test lamp between the intake throttle position sensor low reference circuit (pin 3 of E25) and the battery power supply. Does the test lamp illuminate?

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 Intake throttle valve harness connector inspection.

=>Go to Inspection for open circuit in intake throttle position sensor low reference circuit.

5. Inspection for short to power supply in intake throttle position sensor signal circuit

1) Inspect the position sensor signal circuit between the ECM (pin 25 of E2) and the intake throttle valve (pin 4 of E25) for the following. Is the result normal?

Short to the battery power supply circuit or short to the ignition power supply circuit
Short to the 5 V reference circuit

Note

The intake throttle position sensor may be damaged if the sensor signal circuit is shorted to the power supply.

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 replacement.

Repair the circuit as necessary.

=>Go to Repair verification.

6. Inspection for open circuit in intake throttle position sensor low reference circuit

1) Inspect the position sensor low reference circuit between the ECM (pin 18 of E3) and the intake throttle valve (pin 3 of E25) for an open circuit or high resistance. Is the result normal?

Caution

The intake throttle position sensor shares the low reference circuit with other sensors. A malfunction in the low reference circuit may set DTCs on sensors that share this circuit.

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.

Repair the circuit as necessary.

=>Go to Repair verification.

7. Intake throttle valve harness connector inspection

1) Inspect for poor connections at the intake throttle valve harness connector (pin 3 of E25). 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 intake throttle valve.

Refer to "1.Engine 1B.Mechanical(4JJ3 without DPD) Intake throttle valve removal".

Refer to "1.Engine 1B.Mechanical(4JJ3 without DPD) Intake throttle valve installation".

=>Go to Repair verification.

Repair the connections as necessary.

=>Go to Repair verification.

8. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (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

=>Go to ECM replacement.

Repair the connections as necessary.

=>Go to Repair verification.

9. ECM replacement

Note

Perform programming after replacing the ECM.

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

=>Go to Repair verification.

10. Repair verification

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.