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Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1996 Ford RV Cutaway, 1996 Ford Pickup, 1996 Ford F-Super Duty, 1996 Ford Econoline, and 1996 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

  1. 1) DTC 0571: Check BPA Parameter Identification (PID)

    Ensure scan tool is connected to Data Link Connector (DLC). See VEHICLE PREPARATION & EQUIPMENT HOOKUP  under QUICK TEST. Using scan tool, access BPA PID from PID/DATA MONITOR & RECORD menu. With brake pedal applied, observe BPA PID reading. If BPA PID reading indicates ON only, go to next step. If BPA PID reading does not indicate ON only, go to step  5).

  2. 2) Check BPA Switch

    Turn ignition on. Disconnect BPA switch. If BPA PID does not switch to OFF, go to step  4) (Econoline), or go to next step (Pickup). If BPA PID switches to OFF, replace BPA switch. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  3. 3) Check For Short To Battery Voltage In Black/Yellow Wire

    Turn ignition off. Disconnect PCM 104-pin connector. Turn ignition on. Measure voltage between ground and Black/Yellow wire at BPA switch wiring harness connector. If battery voltage is present, locate and repair short to power in Black/Yellow wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. If battery voltage is not present, short to voltage is at terminal No. 31 at PCM. Inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors, go to step  13).

  4. 4) Check For Short To Battery Voltage In Red/Light Green Wire

    Turn ignition off. Disconnect PCM 104-pin connector. Turn ignition on. Measure voltage between ground and Red/Light Green wire at BPA switch wiring harness connector. If battery voltage is present, locate and repair short to power in Red/Light Green wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. If battery voltage is not present, short to voltage is at terminal No. 31 at PCM. Inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors, go to step  13).

  5. 5) Check BPA PID

    Using scan tool observe BPA PID reading. Depress and release brake pedal. If BPA PID reading indicates OFF only, go to step  7) (Econoline), or go to next step (Pickup). If BPA PID reading does not indicate OFF only, fault may be intermittent. Go to step  14).

  6. 6) Check Fuse No. 5 (15-Amp)

    Remove and inspect fuse No. 5 from instrument panel fuse block. If fuse is blown, replace fuse. If fuse blows again, go to step  8). If fuse is okay, check BPA switch and circuit for open. Go to step  10).

  7. 7) Check Fuse No. 1 (15-Amp)

    Remove and inspect fuse No. 1 from instrument panel fuse block. If fuse is blown, replace fuse. If fuse blows again, go to step  19). If fuse is okay, check BPA switch and circuit for open. Go to step  16).

  8. 8) Check Purple/Orange Wire For Short To Ground

    Ensure BPA switch is disconnected. Measure resistance between ground and Purple/Orange wire at BPA switch wiring harness connector. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, locate and repair short to ground in Purple/Orange wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  9. 9) Check Black/Yellow Wire For Short To Ground

    Disconnect PCM 104-pin connector. Measure resistance between ground and Black/Yellow wire at BPA switch wiring harness connector. If resistance is more than 10 k/ohms, go to step  21). If resistance is 10 k/ohms or less, locate and repair short to ground in Black/Yellow wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  10. 10) Check BPA Switch

    Turn ignition on. Ensure BPA switch is disconnected. Connect a jumper wire between Black/Yellow wire and Purple/Orange wire at BPA switch wiring harness connector. Using scan tool, check BPA PID reading. If BPA PID reading indicates ON, replace BPA switch. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. If BPA PID reading does not indicate ON, go to next step.

  11. 11) Check Purple/Orange Wire For Open

    Turn ignition off. Measure resistance of Purple/Orange wire between BPA switch wiring harness connector and No. 5 fuse holder. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in Purple/Orange wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  12. 12) Check Black/Yellow Wire For Open

    Disconnect jumper wire. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between Black/Yellow wire at BPA switch wiring harness connector and test pin No. 31 at breakout box. If resistance is less than 5 ohms, check for open at terminal No. 31 at PCM. Inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors, go to next step. If resistance 5 ohms or more, locate and repair open circuit in Black/Yellow wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  13. 13) Confirm PCM Fault

    Turn ignition on. Using scan tool, access BPA PID from PID/DATA MONITOR & RECORD menu. While observing BPA PID reading, depress and release brake pedal. If BPA PID switches from ON to OFF, no problem is indicated at this time. If BPA PID does not switch from ON to OFF, replace PCM. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. Repeat QUICK TEST .

  14. 14) Check For Intermittent Open Or Short

    Ensure BPA switch is disconnected. Turn ignition on. Connect a jumper wire between Black/Yellow wire and Purple/Orange wire at BPA switch wiring harness connector. Using scan tool, access BPA PID from PID/DATA MONITOR & RECORD menu. BPA PID reading should indicate ON. While observing BPA PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (BPA PID switches to OFF), isolate fault and repair as necessary. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. If no fault is indicated, go to next step.

  15. 15) Check For Intermittent Short To Power

    Ensure jumper wire is still connected. Remove fuse No. 5 at instrument panel fuse block. Turn ignition on. Using scan tool, access BPA PID from PID/DATA MONITOR & RECORD menu. BPA PID should indicate OFF. While observing BPA PID reading, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (BPA PID switches to ON), isolate fault and repair as necessary. Reconnect all components and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal. If no fault is indicated, no problem is indicated at this time. Repeat QUICK TEST .

  16. 16) Check Light Green/Red Wire For Open

    Turn ignition off. Measure resistance of Light Green/Red wire between BPA switch wiring harness connector and No. 1 fuse holder. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in Light Green/Red wire. Reconnect all connectors and confirm repair using scan tool and accessing BPA PID from PID/DATA MONITOR & RECORD menu while applying brake pedal.

  17. 17) Check For Open BPA Switch

    Reinstall fuse No. 1. Ensure BPA switch is disconnected. Turn ignition on. Connect a jumper wire between Red/Light Green wire and Light Green/Red wire at BPA switch wiring harness connector. Using scan tool, access BPA PID from PID/DATA MONITOR & RECORD menu. If BPA PID reading indicates ON, replace BPA switch and repeat QUICK TEST . If BPA PID reading does not indicate ON, go to next step.

  18. 18) Check Red/Light Green Wire For Open

    Disconnect jumper wire. Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance of Red/Light Green wire between BPA switch wiring harness connector and test pin No. 31 at breakout box. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST . If resistance is 5 ohms or more, locate and repair open circuit in Red/Light Green wire and repeat QUICK TEST .

  19. 19) Check Light Green/Red Wire For Short To Ground

    Remove fuse No. 1 at instrument panel fuse block. Measure resistance between ground and Light Green/Red wire at BPA switch wiring harness connector. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, locate and repair short to ground in Light Green/Red wire. Replace fuse and repeat QUICK TEST .

  20. 20) Check Red/Light Green Wire For Short To Ground

    Remove fuse No. 1 at instrument panel fuse block. Disconnect PCM 104-pin connector. Measure resistance between ground and Red/Light Green wire at BPA switch wiring harness connector. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, locate and repair short to ground in Red/Light Green wire. Replace fuse and repeat QUICK TEST .

  21. 21) Check PCM For Internal Short

    Disconnect BPA connector. Connect PCM connector to breakout box. Measure resistance between test pin No. 31 and test pins No. 25, 76, 77 and 103 at breakout box. If all readings are more than 10 k/ohms, no problem is indicated at this time. If any reading is 10 k/ohms or less, replace PCM. Reinstall fuse and repeat QUICK TEST .
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