SFI SYSTEM, Diagnostic DTC:P2120, P2122, P2123, P2125, P2127, P2128, P2138

DESCRIPTION

The accelerator pedal position sensor is built into the accelerator pedal sensor assembly and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type sensor and uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the accelerator pedal position sensor itself.

The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

MONITOR DESCRIPTION

When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is more than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and stores a DTC.

Example:

When the output voltage of VPA is less than 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is stored.

MONITOR STRATEGY

COMPONENT OPERATING RANGE

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 procedure).

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. Fully depress and release the accelerator pedal [B].

7. Check that 5 seconds or more have elapsed since the ignition switch is turned ON.

8. Enter the following menus: Powertrain / Engine and ECT / DTC [C].

9. Read the 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.

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

11. Input the DTC: P2120, P2122, P2123, P2125, P2127, P2128 or P2138.

12. 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 Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU 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 N/A, perform steps [B] and [C] again.

FAIL-SAFE

When DTC P2120, P2121, P2122, P2123, P2125, P2127, P2128 or P2138 is stored, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.

Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (ACCELERATOR PEDAL POSITION SENSOR)

   
   
   1. 

      Text in Illustration

      *a	Fully Depressed
      *b	Fully Released

      Connect the 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 / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

   5. Read the value displayed on the tester.

      Standard Voltage
      Accelerator Pedal Operation Accel Sensor Out No. 1 Accel Sensor Out No. 2 Fully Released 0.5 to 1.1 V 1.2 to 2.0 V Fully Depressed 2.6 to 4.5 V 3.4 to 4.98 V

   
   

   NG

   CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM) Click here

   OK

   CHECK FOR INTERMITTENT PROBLEMS Click here

2. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

   
   

   1. Disconnect the accelerator pedal sensor assembly connector.

   2. Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition A36-6 (VPA) - A25-51 (VPA) Always Below 1 Ω A36-5 (EPA) - A25-52 (EPA) Always Below 1 Ω A36-4 (VCPA) - A25-53 (VCPA) Always Below 1 Ω A36-3 (VPA2) - A25-54 (VPA2) Always Below 1 Ω A36-2 (EPA2) - A25-55 (EPA2) Always Below 1 Ω A36-1 (VCP2) - A25-56 (VCP2) Always Below 1 Ω A36-6 (VPA) or A25-51 (VPA) - Body ground Always 10 kΩ or higher A36-4 (VCPA) or A25-53 (VCPA) - Body ground Always 10 kΩ or higher A36-3 (VPA2) or A25-54 (VPA2) - Body ground Always 10 kΩ or higher A36-1 (VCP2) or A25-56 (VCP2) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ACCELERATOR PEDAL SENSOR ASSEMBLY)

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to Accelerator Pedal Sensor Assembly)

      Disconnect the accelerator pedal sensor 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 A36-4 (VCPA) - A36-5 (EPA) Ignition switch ON 4.5 to 5.5 V A36-1 (VCP2) - A36-2 (EPA2) Ignition switch ON 4.5 to 5.5 V

   
   

   NG

   REPLACE ECM Click here

   OK

4. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

   
   

   1. Replace the accelerator pedal sensor assembly Click here.

   
   

   NEXT

5. CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL SENSOR DTCS)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the tester on.

   4. Clear the DTCs Click here.

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

   6. Turn the ignition switch to ON.

   7. Turn the tester on.

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

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

   10. Read the DTCs.

       Result

       Result	Proceed to
       DTC P2120, P2122, P2123, P2125, P2127, P2128, and/or P2138 are output	A
       DTC is not output	B

   
   

   B

   END

   A

   REPLACE ECM Click here