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Home >> Ford >> 1994 >> Crown Victoria Base >> Repair and Diagnosis >> Steering >> Power Steering >> Steering System - Power >> Pinpoint Tests >> Pinpoint Test A: EVO System

Pinpoint Test A: EVO System

  1. Check Connections

    Verify EVO actuator valve (on power steering pump) and EVO harness connectors (in trunk) are firmly seated. If connectors are not firmly seated, make proper connections and go to next step. If connections are seated properly, go to next step.

  2. Control Module Check

    Turn ignition off. Locate diagnostic connector (in trunk). Connect EVO system tester to jumper wire and to connector in upper glove compartment. Start engine. Test light will illuminate for one second. If light illuminates for one second, go to next step. If test light flickers or does not illuminate, go to step 32).

  3. Actuator Output Circuit Check

    If Code 6 flashes once and does not repeat, circuit is okay. Go to next step. If Code 6 repeats after 2 second delay, go to step 8).

  4. Steering Wheel Sensor Test

    Start engine. Turn steering wheel lock to lock. Steering wheel must be rotated in one direction at least 220 degrees. If test light illuminates, go to next step. If test light does not illuminate, go to step 20).

  5. VSS Check

    Drive vehicle at least 15 MPH on straight road. Do not turn steering wheel, if possible. If test light remains illuminated for all speeds above 15 MPH, go to next step. If test light turns off at any speed above 15 MPH, go to step 28).

  6. VSS Check

    Reduce vehicle speed to less than 10 MPH. If test light turns off, go to next step. If test light remains illuminated, go to step 28).

  7. Service Power Steering

    Perform pump flow and pressure tests, and repair or replace (as required). See HYDRAULIC SYSTEM PRESSURE & FLOW TEST  under TESTING. Repair power steering components as required.

  8. Code 6 Activated: EVO Actuator Valve Check

    Check for short to ground or open circuit. Ensure EVO wiring harness connectors are properly seated. Verify EVO actuator and harness are undamaged. Repair damaged components as necessary. If connections are not seated, make proper connections and go to step 2). If connections are properly seated, go to next step.

  9. Actuator Valve Circuit Resistance Check

    Verify ignition is off. Locate and disconnect harness connectors at EVO control module. Using an ohmmeter, measure resistance between pins No. 13 and 14 of harness connector. Resistance should be 7-18 ohms. See Fig 1 . If resistance is greater than 1000 ohms, circuit is open. Go to PINPOINT TEST B  , step 3. If resistance is less than 7 ohms, go to next step. If resistance is greater than 18 ohms, but less than 1000 ohms, go to step 11).
    Fig 1: Identifying EVO Control Module Connector Pins
    G92J03994

  10. Wiring Continuity Check

    Verify ignition is off. Disconnect actuator valve connector, located on power steering pump. Test continuity between valve connector and module connector. If continuity does not exist, repair wiring or connector (as required) and go to step 1). If continuity exists on BOTH circuits, go to next step.

  11. Actuator Valve Resistance Check

    Disconnect EVO harness connector at actuator valve. Using an ohmmeter, measure resistance between valve pins. If resistance is 5-20 ohms, go to next step. If resistance is not 5-20 ohms, replace actuator valve.
    NOTE: Always check for pin damage on components before replacement.

  12. Wiring Harness Short To Ground Check

    Verify ignition is off. Disconnect EVO control module harness connector from module. Go to next step.

  13. Wiring Harness Short To Ground Check (Greater Than 1000 Ohms)

    Using an ohmmeter, measure resistance at control module connector between pins No. 5 and 13. If resistance is greater than 1000 ohms, go to step 15). If resistance is less than 1000 ohms, go to next step.

  14. Wiring Harness Short To Ground Check (Less Than 10 Ohms)

    Using an ohmmeter, measure resistance at control module connector between pins No. 5 and 13. If resistance is less than 10 ohms, service harness and go to next step. If resistance is greater than 10 ohms, next step.

  15. Resistance Check (Pin No. 14 Less Than 10 Ohms)

    Using an ohmmeter, measure resistance at control module connector between pins No. 5 and 14. If resistance is less than 10 ohms, service harness. If resistance is greater than 10 ohms, go to next step.

  16. Resistance Check (Pin No. 14 Greater Than 1000 Ohms)

    Using an ohmmeter, measure resistance at control module connector between pins No. 5 and 14. If resistance is greater than 1000 ohms, go to next step. If resistance is less than 1000 ohms, go to step 18).

  17. Harness Short To Battery Positive Check

    Turn ignition on. With EVO actuator valve assembly connector disconnected, measure voltage at control module connector between pins No. 5 and 13 and pins No. 5 and 14. If voltage is greater than 5 volts, repair wiring and go to step 1). If voltage is less than 5 volts, go to next step.

  18. Short Circuit Check (Circuits No. 330 & 353 Less Than 10 Ohms)

    Turn ignition off. Verify EVO harness connector is disconnected at actuator valve. Using an ohmmeter, measure resistance at control module connector between pins No. 13 and 14. If resistance is less than 10 ohms, repair harness and go to step 1). If resistance is greater than 10 ohms, go to next step.

  19. Short Circuit Check (Circuits No. 330 & 353 Greater Than 1000 Ohms)

    Turn ignition off. Verify EVO harness connector is disconnected at actuator valve. Using an ohmmeter, measure resistance at control module connector between pins No. 13 and 14. If resistance is less than 1000 ohms, go to step 1). If resistance is greater than 1000 ohms, replace EVO control module.
    NOTE: Always check for pin damage on components before replacement.

  20. Steering Wheel Rotation Sensor Connector Check

    Verify steering wheel rotation sensor connector, at base of steering column, is properly seated. If connector is properly seated, go to next step. If connector is NOT properly seated, make proper connection and go to step 1).

  21. Steering Wheel Rotation Sensor Check

    Turn ignition off. Disconnect EVO control module harness connector. Examine wiring harness for damage. Verify following wires correspond to these pin numbers:
    • Red/Yellow wire (circuit No. 834) in pin No. 1
    • Red/White wire (circuit No. 835) in pin No. 6
    • Yellow/Black wire (circuit No. 837) in pin No. 12

    If damaged or crossed wires are found, repair harness and go to step 1). If wires are okay, go to next step.

  22. Steering Wheel Rotation Sensor Signal Check

    With control module connector disconnected, start engine. Using an analog ohmmeter set to 1-k/ohm scale, measure resistance between pins No. 1 and 5 and pins No. 5 and 6 while slowly rotating steering wheel. If meter needle swings for both circuits, steering wheel rotation sensor is functional. Replace EVO control module and re-test system. If meter does NOT swing for both circuits, go to next step.
    NOTE: Resistance values will vary between ohmmeters. Needle on all meters should swing from a lower to higher resistance and back, approximately every 9 degrees of steering wheel rotation.

  23. Steering Wheel Rotation Sensor Wire Check

    Turn ignition off. Disconnect EVO control module connector at module. Disconnect connector at steering sensor. Inspect and repair connectors as necessary. Test continuity of circuits No. 834 (Red/Yellow wire), No. 835 (Red/White wire) and No. 837 (Yellow/Black wire) between sensor connector and module connector. If no continuity exists on ANY circuit, repair harness. If continuity exists on ALL circuits, go to next step.

  24. Short Circuit Check

    Turn ignition off. Disconnect steering wheel rotation sensor. Disconnect EVO control module 14-pin connector. Measure resistance between following pins in EVO harness:
    • Pins No. 1 and 6
    • Pins No. 1 and 12
    • Pins No. 6 and 12

    If resistance is greater than 1000 ohms, go to step 26). If resistance is less than 10 ohms, go to next step.

  25. Short Circuit Check

    Turn ignition off. Disconnect steering wheel rotation sensor. Disconnect EVO control module 14-pin connector. Measure resistance between following pins in EVO harness:
    • Pins No. 1 and 6
    • Pins No. 1 and 12
    • Pins No. 6 and 12

    If resistance is less than 10 ohms, service wire(s) as necessary and go to step 1). If resistance is greater than 10 ohms, go to next step.

  26. Testing Steering Wheel Rotation Sensor Power

    Turn ignition on. Using a voltmeter, measure voltage between pins No. 5 and 12. If voltage is zero, circuit is open or shorted. Repair harness and go to step 1). If battery voltage is indicated, go to next step.

  27. Testing Steering Wheel Rotation Sensor Power Circuit

    Verify ignition is on. Using a voltmeter, measure voltage between circuits No. 298 and 837 at steering sensor connector. If battery voltage is indicated, replace steering sensor. If battery voltage is not indicated, replace EVO control module.
    NOTE: Always check for pin damage on components before replacement.

  28. VSS Connector Check

    Verify VSS connector is properly seated. If connector is properly seated, go to next step. If connector is NOT properly seated, make proper connection and go to step 1).

  29. VSS Check

    Turn ignition off. Disconnect EVO control module 14-pin harness connector. Examine wiring harness for damage. Verify following circuits correspond to these pin numbers:
    • Gray/Black wire (circuit No. 679) in pin No. 9
    • Gray/Red wire (circuit No. 359) in pin No. 8

    If damaged or crossed wires are found, repair harness and go to step 1). If wires are okay, go to next step.

  30. Testing VSS Ground Circuit

    Test continuity of VSS ground circuit No. 359. Check continuity between pins No. 5 and 8 of 14-pin EVO harness connector. If circuit is open, repair harness or ground eyelet (as necessary), and go to step 1). If continuity is present, go to next step.

  31. Testing VSS

    Raise vehicle on a lift. Start engine. Verify speedometer operation. If speedometer works properly, replace EVO control module. If speedometer reads zero at all times, go to step 1).
    NOTE: Always check for pin damage on components before replacement.

  32. Test Light Check

    Connect EVO diagnostic light or EVO system tester in another vehicle to ensure tester is functional. Check bulb condition. If test and bulb are good, go to next step. If tester or bulb are faulty, replace as necessary. Go to step 2).

  33. EVO Control Module Check

    Ensure ignition is off. Connect EVO system test light to connector in trunk. Start engine. If test light comes on, go to step 3). If test light does not illuminate, go to next step.

  34. EVO Control Module Check

    Ensure ignition is off. Connect EVO system test light to connector in trunk. Start engine. If test light does not flicker, go to next step. If test light flickers, replace EVO control module.

  35. EVO Control Module Check

    Verify ignition is off. Ensure 14-pin connector is firmly connected to module located in trunk. If connections are firmly secured, go to next step. If connections are not firmly secured, go to step 2).
    NOTE: Always check for pin damage on components before replacement.

  36. Power Feed Check

    Ensure ignition is off. Disconnect 14-pin connector from EVO module in trunk. Turn ignition on. Using voltmeter, measure voltage between pins No. 5 and 7. If battery voltage is indicated, replace EVO control module. If no voltage is indicated, check for open circuit or short circuit in circuit No. 298 (Purple/Orange wire). Repair as necessary. Go to step 1).
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