DTC P0123:00

TP sensor No.1 circuit high input

DETECTION CONDITION

• If the PCM detects that the TP sensor No.1 voltage at the PCM terminal 1BP is above 4.9 V, the PCM determines that the TP sensor No.1 circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (CCM).

• The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Restricts the upper limit of the engine speed.

POSSIBLE CAUSE

• Throttle body connector or terminals malfunction

• PCM connector or terminals malfunction

• TP sensor No.1 malfunction

• Short to power supply in wiring harness between throttle body terminal A and PCM terminal 1BP

• Open circuit in wiring harness between the following terminals:

• Throttle body terminal A—PCM terminal 1BP

• Throttle body terminal D—PCM terminal 1BQ

• PCM malfunction

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

TP1

V

TP sensor No.1

• Accelerator pedal released: Approx. 1.11 V

• Accelerator pedal depressed: Approx. 4.59 V

%

• Accelerator pedal released: Approx. 22%

• Accelerator pedal depressed: Approx. 92%

STEP

INSPECTION

ACTION

1

• Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Access the TP1 PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Verify the TP1 PID value.

• Is the TP1 PID value 5 V or B+?

Yes

Go to Step 7.

No

Go to the next step.

4

• Switch the ignition off.

• Disconnect the throttle body connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 10.

No

Go to the next step.

5

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 10.

No

Go to the next step.

6

• Reconnect all disconnected connectors.

• Inspect the TP sensor No.1.

  (See THROTTLE POSITION (TP) SENSOR INSPECTION [SKYACTIV-G 2.5].)

• Is there any malfunction?

Yes

Replace the throttle body, then go to Step 10.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to Step 10.

7

• Switch the ignition off.

• Disconnect the throttle body connector.

• Access the TP1 PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Verify the TP1 PID value.

• Is the TP1 PID value 5 V or B+?

Yes

Go to the next step.

No

Go to Step 9.

8

• Verify that the throttle body connector is disconnected.

• Switch the ignition off.

• Disconnect the PCM connector.

• Inspect for continuity between throttle body terminal A (wiring harness-side) and PCM terminal 1BP (wiring harness-side).

• Is there continuity?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between throttle body terminal A and PCM terminal 1BP.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 10.

No

Refer to the wiring diagram and verify whether or not there is a common connector between throttle body terminal A and PCM terminal 1BP.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 10.

9

• Verify that the throttle body connector is disconnected.

• Switch the ignition off.

• Disconnect the PCM connector.

• Inspect for continuity between throttle body terminal D (wiring harness-side) and PCM terminal 1BQ (wiring harness-side).

• Is there continuity?

Yes

Replace the throttle body, then go to the next step.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Refer to the wiring diagram and verify whether or not there is a common connector between throttle body terminal D and PCM terminal 1BQ.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to the next step.

10

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Start the engine and warm it up completely.

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [SKYACTIV-G 2.5].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to the next step.

No

Go to the next step.

11

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.