GSIC - Global Service Information Center

### DTC P0120/41 Throttle Pedal Position Sensor / Switch "A" Circuit Malfunction

### DTC P0122/41 Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input

### DTC P0123/41 Throttle / Pedal Position Sensor / Switch "A" Circuit High Input

## for Preparation Click here

## DESCRIPTION

HINT:

1. These troubleshooting procedures are for the throttle position sensor.
2. This electrical throttle system does not use a throttle cable.
3. This throttle valve position sensor is a non-contact type.

The throttle position sensor is mounted on the diesel throttle body and detects the opening angle of the throttle valve. This sensor is electronically controlled and uses Hall-effect elements.
The ECM judges the vehicle's driving conditions from the signals input to its VLU terminal. The data is one of the conditions for EGR control, etc.

DTC No. | DTC Detection Condition | Trouble Area
- | Condition of DTC P0120/41, P0122/41 or P0123/41 continues for 5 seconds (open or short in throttle position sensor circuit) | -

P0120/41

Throttle position sensor output (VLU) flutters up and down beyond normal operating range
(less than 0.2 V or more than 4.8 V)
(1 trip detection logic)

1. Open or short in throttle valve position sensor circuit
2. Throttle position sensor
3. ECM

P0122/41

Throttle position sensor output (VLU) is less than 0.2 V
(1 trip detection logic)

1. Throttle position sensor
2. Open or short in VLU circuit
3. Open in VC circuit
4. ECM

P0123/41

Throttle position sensor output (VLU) is more than 4.8 V
(1 trip detection logic)

1. Throttle position sensor
2. Open in E2 circuit
3. VC and VLU circuits are short-circuited
4. ECM

## MONITOR DESCRIPTION

When the output voltage of the throttle position sensor deviates from the normal operating range (between 0.2 and 4.8 V) for more than 3 seconds, the ECM interprets this as a malfunction of the sensor circuit and illuminates the MIL.

## WIRING DIAGRAM

## INSPECTION PROCEDURE

HINT:

1. If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.

NOTICE:

  If the ECM is replaced, the new ECM needs initialization (Click here).

1.CHECK WIRE HARNESS (THROTTLE POSITION SENSOR - ECM)

1. Disconnect the E7 and E8 ECM connectors.

1. Disconnect the T2 throttle position sensor connectors.

1. Measure the resistance of the wire harness side connectors.

   Standard resistance:

     Tester Connection | Specified Condition
     E8-18 (VC) - T2-1 (VC) | Below 1 Ω
     E7-29 (VLU) - T2-3 (VTA) | Below 1 Ω
     E8-28 (E2) - T2-2 (E2) | Below 1 Ω
     E8-18 (VC) or T2-1 (VC) - Body ground | 10 kΩ or higher
     E7-29 (VLU) or T2-3 (VTA) - Body ground | 10 kΩ or higher
     E8-28 (E2) or T2-2 (E2) - Body ground | 10 kΩ or higher

| NG |

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK |

2.CHECK ECM (VC VOLTAGE)

1. Disconnect the T2 throttle position sensor connectors.

1. Turn the ignition switch ON.

1. Measure the voltage of the ECM connector.

   Standard voltage:

     Tester Connection | Specified Condition
     E8-18 (VC) - E8-28 (E2) | 4.5 to 5.5 V

| NG |

REPLACE ECM

OK |

3.REPLACE DIESEL THROTTLE BODY (THROTTLE VALVE)

NEXT |

4.CHECK IF DTC OUTPUT RECURS (DTC P0120/41, P0122/41 AND/OR P0123/41)

Click here

1. Clear the DTC(s) (Click here).

1. Start the engine.

1. Let the engine idle for 60 seconds, and repeat quick engine revving to 2,500 rpm for 30 seconds.

1. Read the DTC(s).

   Result:

     Display (DTC Output) | Proceed to
     P0120/41, P0122/41 and/or P0123/41 | A
     No output | B

| B |

SYSTEM OK

A |

REPLACE ECM