P0123

DTC P0123: Throttle Position Circuit High Input

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temp.: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 30 sec. or more.
4) Check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. Check TP sensor and its circuit.

Connect scan tool to DLC with ignition switch turned OFF and then turn ignition switch ON.
Check throttle valve opening percentage displayed on scan tool.
Check throttle valve opening percentage displayed on scan tool while opening throttle valve from idle position to full open position.

Is it displayed 100%?
YES
Go to Step 3.
NO
Intermittent trouble.
Check for intermittent referring to Intermittent and Poor Connection Inspection.

3. Check wire harness.

Disconnect connector from TP sensor with ignition switch turned OFF.
Check for proper connection to TP sensor at "GRY/RED", "GRY/BLU" and "ORN" wire terminal.
If OK, then with ignition switch turned ON, check voltage at each of "GRY/RED" and "GRY/BLU" wire terminals.






Is voltage about 4 - 6 V at each terminal?
YES
Go to Step 6.
NO
Go to Step 4.

4. Check ECM voltage.

Check proper connection of connector at "C46-18" and "C46-25" wire terminals.
If OK, disconnect connector from MAP sensor.
Turn ON ignition switch, check voltage between "C46-18" and body ground and between "C46-25" and body ground.

Is voltage about 4 - 6 V at each terminal?
YES
"GRY/RED" and/or "GRY/BLU" wire open circuit.
Check MAP sensor according to Testing and Inspection Manifold Absolute Pressure (MAP) Sensor Inspection.
If they are OK, go to Step 5.
NO
Go to Step 5.

5. Check wire circuit.

Disconnect connector from ECM with ignition switch turned OFF.
Turn ON ignition switch.
Check voltage between "GRY/RED" wire terminal and body ground and between "GRY/BLU" wire terminal and body ground.

Is voltage about 0 V at each terminal?
YES
Go to Step 7.
NO
"GRY/RED" and/or "GRY/BLU" wire shorted to power circuit.
If wire are OK, substitute a known-good ECM and recheck.

6. Check wire circuit.

Measure resistance between "C46-25" terminal and "GRY/BLU" wire terminal in TP sensor connector with ignition switch turned OFF.

Is resistance below 5 ohms?
YES
Go to Step 8.
NO
"GRY/BLU" wire in high resistance circuit.

7. Check ground circuit.

Connect connector to ECM.
Check proper connection of MAP sensor at "ORN" wire terminal.
Measure resistance between "ORN" wire terminal in MAP sensor connector and body ground.

Is resistance below 10 ohms?
YES
Go to Step 10.
NO
Go to Step 9.

8. Check ground circuit.

Measure resistance between "C46-27" terminal and body ground.

Is resistance below 5 ohms?
YES
"ORN" wire open circuit or high resistance circuit. Poor "C46-27" connection.
NO
Faulty ECM ground circuit.
If circuit are OK, substitute a known-good ECM and recheck.

9. Check TP sensor.

Check resistance between terminals of TP sensor.

TP sensor resistance
Between 1 and 3: 4.0 - 6.0 kohms
Between 1 and 2: 0.1 - 6.5 kohms





Are measured values within specifications?
YES
Substitute a known-good ECM and recheck.
NO
Replace TP sensor.