SFI SYSTEM, Diagnostic DTC:P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135

DESCRIPTION

The Throttle Position (TP) sensor is mounted on the throttle body assembly, and detects the opening angle of the throttle valve. This sensor is a non-contact type. It uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions such as at high speeds and very low speeds.

The TP sensor has two sensor circuits which each transmits a signal, VTA1 and VTA2. VTA1 is used to detect the throttle valve angle and VTA2 is used to detect malfunctions in VTA1. The sensor signal voltages vary between 0 V and 5 V in proportion to the throttle valve opening angle, and are transmitted to the VTA terminals of the ECM.

As the valve closes, the sensor output voltage decreases and as the valve opens, the sensor output voltage increases. The ECM calculates the throttle valve opening angle according to these signals and controls the throttle actuator in response to driver inputs. These signals are also used in calculations such as air-fuel ratio correction, power increase correction and fuel-cut control.

CONFIRMATION DRIVING PATTERN

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch to ON and turn the tester on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the tester on [A].

6. Start the engine.

7. With the vehicle stationary, fully depress and release the accelerator pedal [B].

8. Idle the engine for 2 seconds or more [C].

9. Enter the following menus: Powertrain / Engine and ECT / DTC [D].

10. Read pending DTCs.

    Tech Tips

    
    

    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

12. Input the DTC: P0120, P0121, P0122, P0123, P0220, P0222, P0223 or P2135.

13. Check the DTC judgment result.

    Tester Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed You should perform driving pattern after confirming DTC enabling conditions
    UNKNOWN	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    Tech Tips

    
    

    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [D] again.

FAIL-SAFE

When any of these DTCs or other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions are set, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts off the current to the throttle actuator and the throttle valve is returned to a 6.5° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed gently, the vehicle can be driven slowly. Fail-safe mode continues until a pass condition is detected, and the ignition switch is then turned off.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (THROTTLE POSITION NO. 1 AND THROTTLE POSITION NO. 2)

   
   

   1. Connect an intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the tester on.

   4. Enter the following menus: Powertrain / Engine and ECT / Data List / Throttle Position No. 1 and Throttle Position No. 2.

   5. Read the values.

      Result

      When Accelerator Pedal Released		When Accelerator Pedal Depressed		Trouble Area	Proceed to
      Throttle Position No. 1 (VTA1)	Throttle Position No. 2 (VTA2)	Throttle Position No. 1 (VTA1)	Throttle Position No. 2 (VTA2)
      0 V to 0.2 V	0 V to 0.2 V	0 V to 0.2 V	0 V to 0.2 V	VC circuit open	A
      4.5 V to 5.0 V	4.5 V to 5.0 V	4.5 V to 5.0 V	4.5 V to 5.0 V	E2 circuit open
      0 V to 0.2 V, or 4.5 V to 5.0 V	2.1 V to 3.1 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	2.1 V to 3.1 V (Fail-safe)	VTA1 circuit open or ground short
      0.6 V to 1.4 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	0.6 V to 1.4 V (Fail-safe)	0 V to 0.2 V, or 4.5 V to 5.0 V	VTA2 circuit open or ground short
      0.5 V to 1.1 V	2.1 V to 3.1 V	3.2 V to 4.8 V (Not fail-safe)	4.6 V to 5.0 V (Not fail-safe)	Throttle position sensor circuit normal	B

      Tech Tips

      
      

      • DTC P0121 is stored when the voltages output from VTA1 and VTA2 are not consistent with the characteristics of the sensors. Therefore, check the Freeze Frame Data when this DTC is output. Use the following formula to confirm relative fluctuations in voltage.

        Features of sensor output
        VTA2 x 0.8 is approximately equal to VTA1 + 1.11 V
        VTA1: Throttle Position No. 1
        VTA2: Throttle Position No. 2

      • If DTC P0121 is output, proceed to "Check Harness and Connector (Throttle Position Sensor - ECM)".

   
   

   B

   CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS) Click here

   A

2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector: (to Throttle Body Assembly)
      *2	Front view of wire harness connector: (to ECM)

      Disconnect the throttle body assembly connector.

   2. Disconnect the ECM connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition B36-5 (VC) - B8-89 (VCTA) Always Below 1 Ω B36-6 (VTA) - B8-113 (VTA1) Always Below 1 Ω B36-4 (VTA2) - B8-112 (VTA2) Always Below 1 Ω B36-3 (E2) - B8-90 (ETA) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition B36-5 (VC) or B8-89 (VCTA) - Body ground Always 10 kΩ or higher B36-6 (VTA) or B8-113 (VTA1) - Body ground Always 10 kΩ or higher B36-4 (VTA2) or B8-112 (VTA2) - Body ground Always 10 kΩ or higher

   4. Reconnect the throttle body assembly connector.

   5. Reconnect the ECM connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT ECM (VC VOLTAGE)

   
   
   1. 

      Text in Illustration

      *1	Front view of wire harness connector: (to Throttle Body Assembly)

      Disconnect the throttle body assembly connector.

   2. Turn the ignition switch to ON.

   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition C17-5 (VC) - C17-3 (E2) Ignition switch ON 4.5 to 5.5 V

   4. Reconnect the throttle body assembly connector.

   
   

   NG

   REPLACE ECM Click here

   OK

4. REPLACE THROTTLE BODY ASSEMBLY

   
   

   1. Replace the throttle body assembly Click here.

   
   

   NEXT

5. CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)

   
   

   1. Connect an intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the tester on.

   4. Enter the following menus: Powertrain / Engine and ECT / DTC / Clear.

   5. Clear DTCs.

   6. Start the engine.

   7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

   8. Read DTCs.

      Result

      Result	Proceed to
      P0120, P0122, P0123, P0220, P0222, P0223 and/or P2135	A
      No output	B

   
   

   B

   END

   A

   REPLACE ECM Click here