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

CAUTION / NOTICE / HINT

DESCRIPTION

The Throttle Position (TP) sensor is built into the throttle body assembly and detects the opening angle of the throttle valve. This sensor is a non-contact type sensor. 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 transmit 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 power increase correction and fuel-cut control.

FAIL-SAFE

When any of these DTCs as well as 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 the current to the throttle actuator, and the throttle valve is returned to a 6.5° opening 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 position, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly. Fail-safe mode continues until a pass condition is detected and the engine switch is turned off.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

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

   1. Connect the intelligent tester to the DLC3.

   2. Turn the engine switch on (IG) and turn the tester on.

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

   4. Read the values displayed on the tester.

      Result

      Throttle Position No.1 (VTA1) Throttle Position No.2 (VTA2) Throttle Position No.1 (VTA1) Throttle Position No.2 (VTA2) Trouble Area Proceed to When Accelerator Pedal Released When Accelerator Pedal Depressed 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 4.9 V 4.5 V to 4.9 V 4.5 V to 4.9 V 4.5 V to 4.9 V E2 circuit open 0 V to 0.2 V, or 4.5 V to 4.9 V 2.1 V to 3.1 V (Fail-safe) 0 V to 0.2 V, or 4.5 V to 4.9 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 4.9 V 0.6 V to 1.4 V (Fail-safe) 0 V to 0.2 V, or 4.5 V to 4.9 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 4.9 V (Not fail-safe) TP sensor circuit normal B

      Tech Tips

      • DTC P0121 is stored when the VTA1 and VTA2 output voltages are not consistent with the sensor characteristics. Therefore, check the freeze frame data when this DTC is stored. Use the following formula to confirm the relative differences in voltage.

        Characteristic 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 the "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. Disconnect the B7 throttle body connector.

   2. Disconnect the B39 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 B7-5 (VC) - B39-67 (VCTA) Always Below 1 Ω B7-6 (VTA) - B39-115 (VTA1) B7-4 (VTA2) - B39-114 (VTA2) B7-3 (E2) - B39-91 (ETA)

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition B7-5 (VC) or B39-67 (VCTA) - Body ground Always 10 kΩ or higher B7-6 (VTA) or B39-115 (VTA1) - Body ground B7-4 (VTA2) or B39-114 (VTA2) - Body ground

      Text in Illustration

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

   4. Reconnect the throttle body connector.

   5. Reconnect the ECM connector.

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT ECM (VC VOLTAGE)

   

   1. Disconnect the B7 throttle body connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition B7-5 (VC) - B7-3 (E2) Engine switch on (IG) 4.5 to 5.5 V

      Text in Illustration

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

   3. Reconnect the throttle body connector.

   NG

   REPLACE ECM Click here

   OK

4. REPLACE THROTTLE BODY ASSEMBLY

   1. Replace the throttle body Click here.

   NEXT

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

   1. Connect the intelligent tester to the DLC3.

   2. Turn the engine switch on (IG) and turn the tester on.

   3. Clear DTCs Click here.

   4. Start the engine.

   5. Allow the engine to idle for 15 seconds or more.

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

   7. Read DTCs.

      Result

      Result	Proceed to
      DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223 and/or P2135 output	A
      No DTC output	B

   B

   SYSTEM OK

   A

   REPLACE ECM Click here