SFI SYSTEM, Diagnostic DTC:P050031

DTC Code DTC Name
P050031 Vehicle Speed Sensor "A" No Signal

DESCRIPTION

Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle speed using the skid control ECU (brake actuator assembly) and speed sensor. The speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter assembly. The ECM determines the vehicle speed based on the frequency of the pulse signal.

Tech Tips


  • Various systems use the vehicle speed signal distributed from the combination meter assembly. Check all the components possibly related to the speed signal.

  • A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly.

    The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.

  • If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems using the speed signal will not operate normally.

B006F69E03
*a 4-Pulse
*b Skid Control ECU
*c From Speed Sensor
*d Combination Meter Assembly
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P050031 Vehicle Speed Sensor "A" No Signal While vehicle being driven, no vehicle speed sensor signal transmitted to ECM (2 trip detection logic).
  • Open or short in speed signal circuit

  • Combination meter assembly

  • ECM

Comes on DTC stored SAE Code: P0500

MONITOR DESCRIPTION

If there is no speed signal from the combination meter assembly even though the ECM determines that the vehicle is being driven, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Required Sensors/Components (Main)

Vehicle speed sensor

Combination meter

Skid control ECU

Required Sensors/Components (Related)

Shift control ECU

Engine coolant temperature sensor

Crankshaft position sensor

Speed Sensor

Throttle position sensor

Mass air flow meter sub-assembly

Frequency of Operation Continuous

TYPICAL ENABLING CONDITIONS

Engine Running

TYPICAL MALFUNCTION THRESHOLDS

Vehicle speed sensor signal No signal

CONFIRMATION DRIVING PATTERN

B006A90E20
*1 24 km/h
*2 Idling
*3 Engine Switch on (IG)
*4 Total of 30 seconds or more

  1. Connect the GTS to the DLC3.

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

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

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

  5. Turn the engine switch on (IG) and turn the GTS on [A].

  6. Start the engine.

  7. Drive the vehicle at 24 km/h (15 mph) or more for a total of 30 seconds or more [B].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  8. Stop the vehicle.

  9. Enter the following menus: Powertrain / Engine / Trouble Codes [C].

  10. 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.

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

  12. Input the DTC: P050031.

  13. Check the DTC judgment result.

    GTS 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

    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, perform the Confirmation Driving Pattern and check the DTC judgment result again.

WIRING DIAGRAM

B006EO0E24
*1 from Brake Actuator Assembly
*2 Combination Meter Assembly
*3 to Other ECUs

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. READ VALUE USING GTS (VEHICLE SPEED)


    1. Connect the GTS to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine / Data List / Vehicle Speed.


      Powertrain > Engine > Data List
      Tester Display
      Vehicle Speed
    4. Drive the vehicle.

    5. Read the value displayed on the GTS.

      Result
      Result Proceed to
      Values displayed on GTS and speedometer display not equal A
      Values displayed on GTS and speedometer display equal B

    B
    A
  2. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)


    1. Disconnect the combination meter 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
      G34-19 (+S) - A56-39 (SPD) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK COMBINATION METER SYSTEM


    1. Check the circuits that send vehicle speed signals to this system in the combination meter system.

      Click here

      Result
      Proceed to
      NEXT

    NEXT
  4. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.


      Powertrain > Engine > Clear DTCs
    5. Turn the engine switch off and wait for at least 30 seconds.

    6. Start the engine.

    7. Turn the GTS on.

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

    9. Enter the following menus: Powertrain / Engine / Trouble Codes.


      Powertrain > Engine > Trouble Codes

      Tech Tips

      If no DTCs (no pending DTCs) are output to the GTS, the repair has been successfully completed.

      Result
      Proceed to
      NEXT

    NEXT