P0120

COMPONENT DESCRIPTION
The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This one controls engine operation such as fuel cut.
On the other hand, the "Wide open and closed throttle position switch", which is built into the throttle position sensor unit, is not used for engine control.




CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.




ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values, and are measured between each terminal and (ECCS ground) with a voltmeter.




ON BOARD DIAGNOSIS LOGIC




FAIL-SAFE MODE
When the ECM enters the fail-safe mode, the MIL illuminates.

OVERALL FUNCTION CHECK
This procedure can be used for checking the overall function of the throttle position sensor circuit. During this check, a DTC might not be confirmed.

With Consult
(1) Start engine and warm it up sufficiently.
(2) Turn ignition switch "OFF" and wait at least 5 seconds.
(3) Turn ignition switch "ON".
(4) Select "MANU TRIG" and "HI SPEED" in "DATA MONITOR" mode with CONSULT.
(5) Select "THRTL POS SEN" and "ABSOL TH.P/S" in "DATA MONITOR" mode with CONSULT.




(6) Press RECORD on CONSULT SCREEN at the same time accelerator pedal is depressed.




(7) Print out the recorded data and make sure the followings:
- The voltage when accelerator pedal fully released is approximately 0.35 - 0.65V.
- The voltage rise is linear in response to accelerator pedal depression.
- The voltage when accelerator pedal fully depressed is approximately 4V.

OR

Without Consult
(1) Start engine and warm it up sufficiently.
(2) Turn ignition switch "OFF" and wait at least 5 seconds.
(3) Turn ignition switch "ON".




(4) Check the voltage between ECM terminal (23) and (25) (ground) and make sure the followings:
- The voltage when accelerator pedal fully released is approximately 0.35 - 0.65V.
- The voltage rise is linear in response to accelerator pedal depression.
- The voltage when accelerator pedal fully depressed is approximately 4V.

EC-TPS-01 Throttle Position Sensor (DTC: P0120):

WIRING DIAGRAM




DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
1. Start engine and warm it up sufficiently.
2. Turn ignition switch "OFF".
3. Disconnect throttle position sensor harness connector.




4. Make sure that resistance between terminals (2) and (3) changes when opening throttle valve manually.

Throttle valve conditions / Resistance at 25°C (77°F)
Completely closed / Approximately 0.5 K Ohms
Partially open / 0.5 - 4.0 K Ohms
Completely open / Approximately 4.0 K Ohms

If NG, replace throttle position sensor.
To adjust throttle position sensor, perform "BASIC INSPECTION".