Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Lexus >> 2008 >> IS F >> Repair and Diagnosis >> Accessories & Equipment >> Entertainment Systems >> Audio/Visual >> Audio And Visual System >> Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter >> Inspection Procedure

Inspection Procedure

  1. OPERATION OF SPEEDOMETER 
    1. Drive the vehicle and check if the function of the speedometer on the combination meter is normal.

      OK: Actual vehicle speed and the speed indicated on the speedometer are the same. 

      HINT.

      The vehicle speed sensor is functioning normally when the indication on the speedometer is normal

    NG: GO TO METER / GAUGE SYSTEM  (See PROBLEM SYMPTOMS TABLE )

    OK: Go to next step 

  2. INSPECT STEREO COMPONENT AMPLIFIER 
    1. Disconnect the stereo component amplifier connector.
    2. Measure the voltage
      1. Jack up either one of the drive wheels.
      2. Move the shift lever to N.
      3. Turn the engine switch on (IG)
        Fig 1: Identifying Stereo Component Amplifier Connector
        G05753370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Measure the voltage between terminal SPD of the stereo component amplifier and body ground when the drive wheels are turned slowly

        OK: Voltage pulses as shown in the illustration. 

    3. Fig 2: Voltage Pulses Graph
      G04967013Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step 3 

    OK: REPLACE STEREO COMPONENT AMPLIFIER  (See REMOVAL  )

  3. CHECK HARNESS AND CONNECTOR (COMBINATION METER - STEREO COMPONENT AMPLIFIER) 
    1. Disconnect the stereo component amplifier connector and combination meter connector.
      Fig 3: Identifying Stereo Component Amplifier Connector
      G05753370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      P30-11 (SPD) - J34-5 (+S) Engine switch off Below 1 Ω
    3. Fig 4: Identifying Combination Meter Connector
      G05753373Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - STEREO COMPONENT AMPLIFIER) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      P30-11 (SPD) - Body ground Engine switch off 10 kΩ or higher

      HINT:

      If the resistance between terminal SPD and body ground is less than 10 kΩ, there may be a short in a wire harness, connector, or an ECU that is connected to the SPD signal wire.

    2. Fig 5: Identifying Stereo Component Amplifier Connector
      G05753370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OR CHECK EACH ECU 

    OK: REPLACE COMBINATION METER  (See REMOVAL )