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Home >> Ford >> 2000 >> Taurus LX, 3.0 2, AX4N >> Repair and Diagnosis >> External Pages >> Different car >> Section 384 (Engine Controls - Pinpoint Tests - 6.0L (99P F450/550) Diesel) >> Pinpoint Test AY: Brake Pressure Applied (BPA) Switch >> Test Procedure

Test Procedure

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  1. AY1 CHECK THE BPA SIGNAL 
    NOTE: Full brake pedal application may be necessary to correctly operate the BPA switch.
    • Key ON, engine OFF.
    • Access the PCM and monitor the BPA PID.
    • Monitor the BPA PID while applying and releasing the brake pedal.

    Does the BPA PID state change when the brake pedal is fully applied and released? 

    Yes No
    UNABLE to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. REFER to SYMPTOM CHARTS , if a driveability concern exists. GO to  AY2.
  2. AY2 CHECK THE BPA SIGNAL VOLTAGE 
    NOTE: Full brake pedal application may be necessary to correctly operate the BPA switch.
    • Key in OFF position.
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) PCM Connector, Harness Side ( - )
      BPS - Pin B28 Ground
    • Fully apply and release the brake pedal while measuring the voltage.

    Is voltage greater than 10 volts with the brake pedal released and less than 1 volt with the brake pedal fully applied? 

    Yes No
    GO to  AY5. GO to  AY3.
  3. AY3 CHECK THE BPA SENSOR VOLTAGE 
    • Key in OFF position.
    • BPA Switch connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) BPA Switch Connector, Harness Side ( - )
      B+ Ground

    Is the voltage greater than 10 V? 

    Yes No
    GO to  AY4. REPAIR the open circuit. CLEAR the DTCs.
    REPEAT the self-test.
  4. AY4 CHECK THE BPA SWITCH 
    NOTE: Full brake pedal application may be necessary to correctly operate the BPA switch.
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) BPA Switch Connector, Component Side ( - ) BPA Switch Connector, Component Side
      B+ BPS
    • Fully apply and release the brake pedal while measuring the resistance.

    Is the resistance less than 5 ohms with the pedal released and greater than 10,000 ohms with the pedal fully applied? 

    Yes No
    REPAIR the signal circuit.
    CLEAR the DTCs. REPEAT the self-test.    		 INSTALL a new BPA switch. CLEAR the DTCs. REPEAT the self-test.
  5. AY5 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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