CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM(for 8NR-FTS), 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.

Tip:

  • 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.

A115899E21

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. 2 seconds

  4. 1-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.

WIRING DIAGRAM

Refer to Speed Signal Circuit.

Click hereClick hereClick hereClick here

CAUTION / NOTICE / HINT

Tip:

  • 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 at 24 km/h (15 mph) or more.

    3. 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.

      Tip:

      • 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 hereClick hereClick hereClick 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 at 24 km/h (15 mph) or more.

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

    10. Read the DTCs.

      Powertrain > Transmission > Trouble Codes

      Tip:

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

    Result

    Proceed to

    NEXT
    NEXT

    END