DTC P0122 (Flash Code 43) Throttle Position 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. Prioritized DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

4) Observe the DTC information with a scan tool. Is DTC P1655 set at the same time?

Yes

Go to DTC P1655 diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P1655 (Flash Code 59) Sensor Reference Voltage 4 Circuit".

No

=>Go to Intake throttle position sensor signal voltage check.

3. Intake throttle position sensor signal voltage check

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

Value: 0.3 V

Yes

=>Go to Intake throttle position sensor 5 V reference voltage check.

No

Go to Intermittent conditions of engine.

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

4. Intake throttle position sensor 5 V reference voltage check

1) Turn OFF the ignition switch.

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

3) Turn ON the ignition switch.

4) Measure the voltage between the intake throttle position sensor 5 V reference circuit (pin 2 of E25) and the body ground with a DMM. Is the voltage more than or equal to the specified value?

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.).

Value: 4.5 V

Yes

=>Go to Intake throttle position sensor signal voltage check using fused jumper wire.

No

=>Go to Inspection for open circuit in intake throttle position sensor 5 V reference circuit.

5. Intake throttle position sensor signal voltage check using fused jumper wire

1) Connect a fused jumper wire between the 5 V reference circuit and the signal circuit of the intake throttle position sensor (pins 2 and 4 of E25).

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.).

2) 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: 4.5 V

Yes

=>Go to Intake throttle valve harness connector inspection.

No

=>Go to Inspection for open circuit and short circuit in intake throttle position sensor signal circuit.

6. Inspection for open circuit in intake throttle position sensor 5 V reference circuit

1) Inspect the position sensor 5 V reference circuit between the ECM (pin 14 of E4) and the intake throttle valve (pin 2 of E25) for an open circuit or high resistance. 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.

7. Inspection for open circuit and short circuit in intake throttle position sensor signal circuit

1) Inspect the position sensor signal circuit between the ECM (pin 4 of E4) and the intake throttle valve (pin 4 of E25) 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.

8. Intake throttle valve harness connector inspection

1) Inspect for poor connections at the intake throttle valve harness connector (pins 2 and 4 of E25). 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

Replace the intake throttle valve.

Refer to "1.Engine 1B.Mechanical(RZ4E-TC) Intake throttle valve removal".

Refer to "1.Engine 1B.Mechanical(RZ4E-TC) Intake throttle valve installation".

=>Go to Repair verification.

No

Repair the connections as necessary.

=>Go to Repair verification.

9. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pins 4 and 14 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.

10. 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.

11. 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.