P0120
NOTE: If DTC P0510 (0203) is displayed with DTC P0120, perform TROUBLE DIAGNOSES FOR DTC P0510 first.
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. The throttle position sensor unit has a built-in "Wide open and closed throttle position switch".
Consult-II Reference Value In Data Monitor Mode:
ECM Terminals And Reference Value:
On Board Diagnosis Logic:
ON BOARD DIAGNOSIS LOGIC
Perform "Procedure for malfunction A" first. If the DTC cannot be confirmed, perform "Procedure for malfunction B". If there is no problem on "Procedure for malfunction B", perform "Procedure for malfunction C".
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
Procedure for malfunction A
CAUTION: Always drive vehicle at a safe speed.
TESTING CONDITION:
- Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.
- This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test is expected to be easier, it is unnecessary to lift the vehicle.
With Consult
1. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT-II.
2. Start engine and maintain the following conditions for at least 5 consecutive seconds.
VHCL SPEED SE: More than 4 km/h (2 MPH)
Selector lever: Suitable position except "P" or "N" position
3. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
OR
With Generic Scan Tool
Follow the procedure "With CONSULT-II" above.
Procedure for malfunction B
With Consult
1. Turn ignition switch "ON".
2. Select "DATA MONITOR" mode with CONSULT-II
3. Start engine and let it idle for at least 10 seconds. If idle speed is over 1,100 rpm, maintain the following conditions for at least 10 seconds to keep engine speed below 1,100 mm.
Selector lever: Suitable position except "P" or "N"
Brake pedal: depressed
Vehicle speed: 0 km/h (6 MPH)
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
OR
With Generic Scan Tool
Follow the procedure "With CONSULT-II" above.
Procedure for malfunction C
With Consult
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Turn ignition switch "ON".
4. Select "MANU TRIG" in "DATA MONITOR" mode with CONSULT-II.
5. Select "THRTL POS SEN" and "ABSOL TH.P/S" in "DATA MONITOR" mode with CONSULT-II.
6. Press RECORD on CONSULT-II screen at the same time accelerator pedal is depressed.
7. Print out the recorded graph and check the following:
- The voltage rise is linear in response to accelerator pedal depression.
- The voltage when accelerator pedal is fully depressed is approximately 4 V.
If NG, go to "DIAGNOSTIC PROCEDURE". If OK, go to following step.
8. Select "AUTO TRIG" in "DATA MONITOR" mode with CONSULT-II.
9. Maintain the following conditions for at least 10 consecutive seconds.
CMPS-RPM (POS): More than 2,000 rpm
MAS AIR/FL SE: More than 3 V
COOLAN TEMP/S: More than 70 °C (158 °F)
Selector lever: Suitable position
Driving location: Driving vehicle uphill (Increased engine load) will help maintain the driving conditions required for this test.
10. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
OR
With Generic Scan Tool
1. Maintain the following conditions for at least 10 consecutive seconds.
Gear position: Suitable position
Engine speed: More than 2,000 rpm
Voltage between ECM terminal (65) and (128) (ECM ground):
More than 3 V
COOLAN TEMP/S: More than70 °C (158°F)
2. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
OR
Without Scan Tools
1. Maintain the following conditions for at least 10 consecutive seconds.
Gear position: Suitable position
Engine sped: More than 2,000 rpm
Voltage between ECM terminal (65) and (128) (ECM ground):
More than 3 V
Voltage between ECM terminal (67) and (128) (ECM ground):
Less than 1.5 V
2. Stop the vehicle, turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
3. Perform "DIAGNOSTIC TEST MODE (Self-diagnostic results)" with ECM.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
EC-TPS-01:
EC-TPS-01 Connector View:
WIRING DIAGRAM
Super Multiple Junction (SMJ) Terminal Arrangement (B3, D1, D21, E66, M4, M6, M11, M12, M45, N1):
Super Multiple Junction (SMJ) Terminal Arrangement (B4, B101, E70, E81, F63, M3, M49, M50):
DIAGNOSTIC PROCEDURE
If the trouble is duplicated after "Procedure for malfunction A", perform "Procedure A". If the trouble is duplicated after "Procedure for malfunction B", perform "Procedure B". If the trouble is duplicated after "Procedure for malfunction C", perform "Procedure C".
Part 1:
Part 2:
Procedure A
Part 1:
Part 2:
Procedure B
Part 1:
Part 2:
Procedure C
COMPONENT INSPECTION
Throttle position sensor
1. Start engine and warm it up to normal operating temperature.
2. Stop engine (Ignition switch "OFF").
3. Remove the vacuum hose connected to the throttle opener.
4. Connect suitable vacuum hose to the vacuum pump and the opener.
5. Apply vacuum [more than -40.0 kPa (-300 mmHg, -11.81 inHg)] until the throttle drum becomes free from the rod of the throttle opener.
6. Turn ignition switch "ON".
With Consult
7. Select "DATA MONITOR" mode with CONSULT-II.
8. Check voltage of "THRTL POS SEN".
Voltage measurement must be made with throttle position sensor installed in vehicle.
If NG, adjust closed throttle position switch. Refer to "Basic Inspection".
9. If it is impossible to adjust closed throttle position switch in "Basic Inspection", replace throttle position sensor.
OR
Without Consult
7. Check voltage between ECM terminal (63) (Throttle position sensor signal) and ground.
Voltage measurement must be made with throttle position sensor installed in vehicle.
If NG, adjust closed throttle position switch. Refer to "Basic Inspection".
8. If it is impossible to adjust closed throttle position switch in "Basic Inspection", replace throttle position sensor.