13A-DTC P0123: Throttle Position Sensor (Main) Circuit High Input

DTC P0123: Throttle Position Sensor (main) Circuit High Input

CIRCUIT OPERATION

A 5-volt power supply is applied on the throttle position sensor (main) power terminal from the ECM terminal TPS5.
A voltage that is according to the throttle opening angle is sent to the ECM terminal TPSM from the throttle position sensor (main) output terminal
The ground terminal is grounded with ECM terminal TPSE.

TECHNICAL DESCRIPTION

The throttle position sensor (main) outputs voltage which corresponds to the throttle valve opening angle.
The ECM checks whether the voltage is within a specified range.

DESCRIPTIONS OF MONITOR METHODS

Throttle position sensor (main) output voltage is out of specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC set in memory for the item monitored below)

Not applicable

Sensor (The sensor below is determined to be normal)

Not applicable

DTC SET CONDITIONS

Logic Flow Chart

Check Condition

Ignition switch is "ON" position.

Judgment Criterion

Throttle position sensor (main) output voltage should be 4.8 volts or more for 0.3 second.

FAIL-SAFE AND BACKUP FUNCTION

Throttle opening degree is restricted.
Throttle opening degree position is in default position if throttle position sensor (sub) fails.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )

Throttle position sensor (main) failed.
Open or shorted throttle position sensor (main) circuit, harness damage, or connector damage.
ECM failed.

DIAGNOSIS

Required Special Tool:

MB991658: Test Harness

STEP 1. Using scan tool (M.U.T.-IIISE), check data list item 13: Throttle Position Sensor (main).

caution

To prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).

(1) Connect scan tool (M.U.T.-IIISE) to the data link connector.

(2) Detach the intake air hose at the throttle body.

(3) Disconnect the connector of the throttle body assembly.

(4) Use test harness special tool (MB991658) to connect only terminals TPSE, TPSM, TPS5 and TPSS line.

(5) Turn the ignition switch to the "ON" position.

(6) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 13, Throttle Position Sensor (main).

Output voltage should be between 300 and 700 millivolts when the throttle valve is fully closed with your finger.
Output voltage should be 4,000 millivolts or more when the throttle valve is fully open with your finger.

(7) Turn the ignition switch to the "LOCK" (OFF) position.

Is the sensor operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Go to Step 2.

STEP 2. Measure the sensor supply voltage at throttle position sensor harness side connector.

(1) Disconnect the throttle body assembly connector and measure at the harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal TPS5 line and ground.

Voltage should be between 4.9 and 5.1 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Is the measured voltage between 4.9 and 5.1 volts?

Go to Step 5.

Go to Step 3.

STEP 3. Check of short to ground and open circuit in TPS5 line between throttle body assembly connector and ECM connector.

Is the harness wire in good condition?

Go to Step 4.

Repair the connector(s) or wiring harness. Then go to Step 11.

STEP 4. Using scan tool (M.U.T.-IIISE), check data list item 13: Throttle Position Sensor (main).

(1) Detach the intake air hose at the throttle body.

(2) Disconnect the connector of the throttle body assembly.

(3) Use test harness special tool (MB991658) to connect only terminals TPSE, TPSM, TPS5 and TPSS line.

(4) Turn the ignition switch to the "ON" position.

(5) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 13, Throttle Position Sensor (main).

Output voltage should be between 300 and 700 millivolts when the throttle valve is fully closed with your finger.
Output voltage should be 4,000 millivolts or more when the throttle valve is fully open with your finger.

(6) Turn the ignition switch to the "LOCK" (OFF) position.

Is the sensor operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Replace the ECM (Refer to Removal and Installation

). Then go to Step 11.

STEP 5. Check the continuity at throttle position sensor harness side connector.

(1) Disconnect the throttle body assembly connector and measure at the harness side.

(2) Measure the continuity between terminal TPSE line and ground

Continuity (2 ohms or less)

Does continuity exist?

Go to Step 7.

Go to Step 6.

STEP 6. Check of open circuit and harness damage in TPSE line between throttle body assembly connector and ECM connector.

Is the harness wire in good condition?

Go to Step 4.

Repair the connector(s) or wiring harness. Then go to Step 11.

STEP 7. Check of harness damage in TPS5 line between throttle body assembly connector and ECM connector.

Is the harness wire in good condition?

Go to Step 8.

Repair the connector(s) or wiring harness. Then go to Step 11.

STEP 8. Check of open circuit and harness damage in TPSM line between throttle body assembly connector and ECM connector.

Is the harness wire in good condition?

Go to Step 9.

Repair the connector(s) or wiring harness. Then go to Step 11.

STEP 9. Using scan tool (M.U.T.-IIISE), check data list item 13: Throttle Position Sensor (main).

(1) Detach the intake air hose at the throttle body.

(2) Disconnect the connector of the throttle body assembly.

(3) Use test harness special tool (MB991658) to connect only terminals TPSE, TPSM, TPS5 and TPSS line.

(4) Turn the ignition switch to the "ON" position.

(5) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 13, Throttle Position Sensor (main).

Output voltage should be between 300 and 700 millivolts when the throttle valve is fully closed with your finger.
Output voltage should be 4,000 millivolts or more when the throttle valve is fully open with your finger.

(6) Turn the ignition switch to the "LOCK" (OFF) position.

Is the sensor operating properly?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Go to Step 10.

STEP 10. Replace the throttle body assembly.

(1) Replace the throttle body assembly.

(2) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1

(3) Check the diagnostic trouble code (DTC).

Is DTC P0123 set?

Replace the ECM (Refer to Removal and Installation

). Then go to Step 11.

The inspection is complete.

STEP 11. Test the OBD-II drive cycle.

(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1

(2) Check the diagnostic trouble code (DTC).

Is DTC P0123 set?

Retry the troubleshooting.

The inspection is complete.