СИСТЕМА МЕХАНИЧЕСКОЙ ТРАНСМИССИИ, 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 sensors. Each speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signals 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.

B0042VEE21
*a 4-Pulse
*b from Speed Sensor
*c Skid Control ECU
*d Combination Meter Assembly
DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory Note
P050031 Vehicle Speed Sensor "A" No Signal

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other


  1. Vehicle is being driven

  2. Vehicle speed signal is not input

  3. 5.25 seconds

  4. 2-trip detection logic

  • Open or short in speed signal circuit

  • Combination meter assembly

  • ECM

 Does not come 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.

WIRING DIAGRAM

Refer to Speed Signal Circuit.

Click here

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.

  • After performing repair, clear the DTCs and perform the following procedure to check that DTCs are not output.


    1. Turn the ignition switch to ON and wait for 3 seconds or more.

    2. Drive the vehicle for 6 seconds or more.

    3. Turn the ignition switch off.

    4. Perform steps (a) and (b) again.

    5. Check for DTCs again.

      Click here

PROCEDURE


  1. READ VALUE USING GTS (VEHICLE SPEED)


    1. Drive the vehicle and check whether the operation of the speedometer in the combination meter assembly is normal.

      Tech Tips


      • The vehicle speed sensor is operating normally if the speedometer reading is normal.

      • If the speedometer does not operate, check it by following the diagnostic procedure for a malfunction of the speedometer.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON and turn the GTS on.

    4. Enter the following menus: Powertrain / Transmission / Data List / Vehicle Speed.


      Powertrain > Transmission > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Vehicle Speed Vehicle speed

      Min.: 0 km/h (0 mph)

      Max.: 255 km/h (158 mph)

      		 Actual vehicle speed

      • This is the current vehicle speed.

      • The vehicle speed is detected using the wheel speed sensors.


        • There is a delay in when the vehicle speed data is displayed. Therefore, even if the vehicle speed listed in the freeze frame data is 0 km/h (0 mph), this does not always mean that the malfunction occurred when the vehicle was stopped.

      Powertrain > Transmission > Data List
      Tester Display
      Vehicle Speed

    5. Drive the vehicle.

    6. According to the display on the GTS, read the Data List.

      OK
      The values displayed on the GTS and speedometer are equal.
      Result
      Proceed to
      OK
      NG

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

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


    1. Disconnect the E46 combination meter assembly connector.

    2. Disconnect the A173 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E46-6 (+S) - A173-44 (SPD) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK METER / GAUGE SYSTEM


    1. Proceed to Speed Signal Circuit in Meter/Gauge 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 ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTCs.


      Powertrain > Transmission > Clear DTCs

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

    6. Start the engine.

    7. Turn the GTS on.

    8. Drive the vehicle for 6 seconds or more.

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

    10. Read the DTCs.


      Powertrain > Transmission > Trouble Codes

      Tech Tips

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

      Result
      Proceed to
      NEXT

    NEXT

    END