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Home >> Ford >> 1991 >> Bronco 4.9 Y, Standard, M5OD-R2 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> EDIS System (4.0L AEROSTAR, Explorer, NAVAJO & Ranger) >> Pinpoint Test A

Pinpoint Test A

  1. Perform EEC-IV Quick Test  If Quick Test was performed according to the procedures in TESTS W/CODES EEC-IV article, go to step 2). If Quick Test was not tested as specified, go to article and perform Quick Test procedure.
  2. Check For Spark During Cranking  Using a spark tester, check for spark at all spark plug wires while cranking. If spark was present and consistent on ALL spark plug wires (one spark per crankshaft revolution), go to step 3). If spark was not as specified, go to step 7).
  3. Check PIP Signal At EDIS Module  With ignition off, connect EDIS diagnostic cable to BOB, EDIS module and coil pack. DO NOT connect VR sensor tee. Use EDIS diagnostic "6" overlay on BOB (if available). Connect EDIS diagnostic cable negative lead to battery, leaving positive lead disconnected. Set EDIS diagnostic cable box switch to "4/6 Cylinder" position. Set DVOM on 20-volt AC scale. Crank engine, and measure voltage between PIPE (43) and BAT (7) at BOB. If stabilized AC voltage reading is 4.5 volts or more, go to step 4). If reading was less than 4.5 volts, go to step 8).
  4. Check For PIP Open To ECA  With ignition off, disconnect ECA. Connect ECA BOB to ECA harness connector. Set DVOM on 200-ohm scale. Measure resistance between PIPE (43) at BOB and PIP (56) at ECA BOB. If resistance is less than 5 ohms, go to step 5). If resistance is 5 ohms or more, repair open circuit. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  5. Check IGN GND At EDIS Module  With ignition off and ECA disconnected, set DVOM on 2-k/ohm scale. Measure resistance between IGN GND E (47) and BAT (7) at BOB. If resistance is less than 1025 ohms, go to step 6). If resistance is 1025 ohms or more, go to step 11).
  6. Check IGN GND Open Circuit To ECA  With ignition off, and ECA disconnected, set DVOM on 2-k/ohm scale, measure resistance between IGN GND E (47) at BOB and terminal No. 16 (IGN GND) of ECA BOB. If resistance is less than 1025 ohms, remove test equipment. Reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If Continuous Memory Code 16 and/or 18 is still present, go to PINPOINT TEST B, Step 1). If no codes are present, go to TESTS W/O CODES article for no start problems. If resistance is 1025 ohms or more, repair ignition ground to ECA open circuit. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  7. Check Spark Plugs & Wires  Check spark plug wires for insulation damage, looseness or shorts. Remove and check spark plugs for damage, wear, carbon deposits and correct plug gap. If spark plugs and wires are okay, reinstall plugs and wires and go to step 12). If spark plugs and wires are defective, repair or replace damaged components as necessary. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  8. Isolate EDIS Module  PIP Fault - With ignition off, connect EDIS diagnostic cable positive lead to battery. Set DVOM to 20-volt AC scale. Hold the EDIS diagnostic cable PIP Push Button down. Crank engine and measure voltage between PIPE (43) and BAT (7) at BOB. If settled AC voltage reading is 4 volts or more, go to step 9). If voltage is less than 4 volts, repair or replace damaged component. Remove test equipment, and reconnect all components. Clear Continuous Memory Codes, and Rerun Quick Test.
  9. Check For PIP Short To Ground  Isolate EDIS Module & ECA With ignition off, disconnect ECA. Disconnect EDIS module from EDIS module tee. Leave EDIS diagnostic cable connected to EDIS module side of vehicle harness connector. Disconnect EDIS diagnostic cable positive lead at battery. Set DVOM on 200-ohm scale. Measure resistance between PIPE (43) and BAT (7) at BOB. If resistance is less than 10 ohms, repair PIP short circuit to ground. Remove test equipment and reconnect all components. Clear Continuous Memory and Rerun Quick Test. If resistance is 10 ohms or more, go to step 10).
  10. Check For PIP Short To VBAT  Isolate EDIS Module & ECA With ignition off and ECA disconnected, set DVOM on 20-volt DC scale. With KOEO, measure voltage between PIPE (43) and BAT (7) at BOB. If DC voltage is .5 volt or more, repair short circuit. PIP is shorted to power. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If voltage less than .5 volt, replace ECA. PIP circuit is shorted internally in ECA. Remove test equipment and reconnect all components. Clear Continuous Memory and Rerun Quick Test.
  11. Check PWR GND To EDIS Module  IGNGND Fault - With ignition off, set DVOM on 2-k/ohm scale. Measure resistance between PWRGNDE (27) and BAT (7) at BOB. If resistance is less than 1050 ohms, replace EDIS module. Ground circuit is open in EDIS module. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is 1050 ohms or more, repair open circuit. PWRGND circuit to EDIS module is open. Remove test equipment and reconnect all components. Clear Continuous Memory and Rerun Quick Test.
  12. Check Vehicle Performance  If the original problem was vehicle cranks but does not start, go to step 13). If not, go to PINPOINT TEST D step 1).
  13. Check PWR GND to EDIS Module  With ignition off and ECA disconnected, connect EDIS diagnostic cable to BOB, EDIS module, and coil pack. Do not connect VR sensor tee. Use EDIS "6" overlay (if available). Connect EDIS diagnostic cable negative lead to battery, leave positive lead disconnected. Set EDIS diagnostic cable box switch to "4/6 cylinder" position. Set DVOM on 2-k/ohm scale. Measure resistance between PWRGND (27) and BAT (7) at BOB. If resistance is less than 5 ohms, go to step 14). If resistance is 5 ohms or more, repair open circuit. Remove all test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  14. Check For VBAT Open To EDIS Module  With ignition off and ECA disconnected, set DVOM on 20-volt DC scale. With KOEO, measure voltage between VBATE (51) and BAT (7) at BOB. If DC voltage is 10.5 volts or more, go to step 15). If voltage is less than 10.5 volts, repair open VBAT to EDIS module circuit. Remove all test equipment and reconnect all components. Clear Continuous Memory and Rerun Quick Test.
  15. Check VRS(+) Bias At EDIS Module  With ignition off and ECA disconnected, set DVOM on 20-volt DC scale. With KOEO, measure voltage between VRS+E (35) and BAT (7) at BOB. If the DC voltage is .8-2.2 volts, proceed to step 16). If voltage is not as specified, proceed to step 17).
  16. Check VRS Amplitude At EDIS Module  With ignition off, reconnect ECA. Disconnect EDIS diagnostic cable negative lead from battery. Set DVOM on 20-volt AC scale. Crank engine, and measure voltage between VRS+E (35) and VRSE (48) at BOB. If stabilized AC voltage reading is .4 volt or more, go to PINPOINT TEST D, step 1). If voltage is less than .4 volt, go to step 25).
  17. Check VRS(+) Bias  Isolate VR Sensor - With ignition off and ECA disconnected, disconnect VR sensor from vehicle harness connector. Set DVOM on 20-volt DC scale. With KOEO, measure voltage between VRS+E (35) and BAT (7) at BOB. If DC voltage is .8-2.2 volts, go to step 21). If voltage is not .8-2.2 volts, go to step 18).
  18. Check VRS(+) High Or Low  If bias voltage reading in step 17) was less than .8 volt, go to step 19). If bias voltage reading in step 17) was .8 volt or more, go to step 20).
  19. Check VRS(+) For Short To Ground  Isolate EDIS Module With ignition off and ECA disconnected, disconnect EDIS module from EDIS diagnostic cable module tee, leave diagnostic cable connected to vehicle harness connector. Set DVOM on 2-k/ohm scale. Measure resistance between VRS+E (35) and BAT (7) at BOB. If resistance is less than 1025 ohms, repair short circuit. VRS(+) is shorted to ground. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is 1025 ohms or more, replace EDIS module. VRS(+) is shorted to ground. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  20. Check VRS(+) For Short To Power  Isolate EDIS Module With ignition off and ECA disconnected, disconnect EDIS module from EDIS diagnostic cable module tee, leave EDIS diagnostic cable connected to vehicle harness connector. Set DVOM on 20-volt DC scale. With KOEO, measure voltage between VRS+E (35) and BAT (7) at BOB. If DC voltage is .5 volt or more, repair short circuit. VRS(+) circuit is shorted to power. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If voltage is less than .5 volt, replace EDIS module. VRS(+) circuit is shorted to power. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  21. Check VRS(-) Bias  With ignition off and ECA disconnected, set DVOM on 20-volt DC scale. With KOEO, measure voltage between VRSE (48) and BAT (7) at BOB. If DC voltage is .8-2.2 volts, replace VR sensor. Short to ground in VR sensor. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If voltage is not .8-2.2 volts, proceed to step 22).
  22. Check VRS(-) Signal High Or Low  If DC bias voltage reading in step 21) is less than .8 volt, go to step 23). If voltage is .8 volt or more, go to step 24).
  23. Check VRS(-) For Short To Ground  Isolate EDIS Module With ignition off and ECA disconnected, disconnect EDIS module from EDIS diagnostic cable module tee, leave diagnostic cable connected to vehicle harness connector. Set DVOM on 2-k/ohm scale. Measure resistance between VRSE (48) and BAT (7) at BOB. If resistance is less than 1025 ohms, repair short circuit. VRS circuit is shorted to ground. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is 1025 ohms or more, replace EDIS module. VRS circuit is shorted to ground. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  24. Check VRS(-) For Short To VBAT  Isolate EDIS Module With ignition off and ECA disconnected, disconnect EDIS module from EDIS diagnostic cable module tee, leaving EDIS diagnostic cable connected to vehicle harness connector. Set DVOM on 20-volt DC scale. With KOEO, measure voltage between VRSE (48) and BAT (7) at BOB. If DC voltage is .5 volt or more, repair short circuit. VRS(-) circuit is shorted to VBAT. Remove test equipment, and reconnect all components. Clear Continuous Memory Codes, and rerun Quick Test. If voltage is less than .5 volt, replace EDIS module. VRS(-) circuit is shorted to VBAT. Remove test equipment, and reconnect all components. Clear Continuous Memory Codes, and rerun Quick Test.
  25. Check VRS Amplitude At EDIS Module  Isolate EDIS Module. With ignition off and ECA disconnected, disconnect EDIS module from EDIS diagnostic cable module tee, leave diagnostic cable connected to vehicle harness connector. Set DVOM on 20-volt AC scale. Crank engine and measure voltage between VRS+E (35) and VRSE (48) at BOB. If stabilized AC voltage reading is .4 volt or more, replace EDIS module. VRS(+) circuit is shorted to VRS(-). Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If stabilized AC voltage reading is less than .4 volt, go to step 26).
  26. Check VRS Resistance  With ignition off and ECA disconnected, disconnect EDIS diagnostic cable negative lead from battery. Set DVOM on 20-k/ohm scale. Measure resistance between VRSE (48) and VRS+E (35) at BOB. If resistance is 2580-2470 ohms, go to step 27). If resistance is not 2580-2700 ohms, go to step 28).
  27. Check VRS Air Gap  With ignition off, check VRS air gap. Ensure there is an air gap between sensor and trigger wheel. Air gap is not adjustable. If air gap is okay, replace VR sensor. Remove all test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If air gap is not okay, repair or replace components as required. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  28. Check VRS High Or Low Resistance  With ignition off and ECA disconnected, disconnect EDIS diagnostic cable negative lead from battery. Set DVOM on 20-k/ohm scale. Measure resistance between VRSE (48) and VRS+E (35) at BOB. If resistance is less than 2550 ohms, go to step 29). If resistance is 2550 ohms or more, go to step 30).
  29. Check VRS(+) For Short To VRS(-) (Isolate VRS)  With ignition off and ECA disconnected, disconnect VR sensor from vehicle harness connector. Set DVOM on 200-k/ohm scale. Measure resistance between VRS+E (35) and VRSE (48) at BOB. If resistance is 3000 ohms or more, replace VR sensor. Sensor windings are shorted. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is less than 3000 ohms, repair short circuit. VRS(+) shorted to VRS(-). Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
  30. Check For VRS(+) Open Circuit (Resistance High Fault)  With ignition off and ECA disconnected, connect EDIS diagnostic cable VR sensor tee to VR sensor and vehicle harness connector. Set DVOM on 20-k/ohm scale. Measure resistance between VRS+S (31) and VRS+E (35) at BOB. If resistance is 2025 ohms or more, repair open circuit. VRS(+) circuit is open. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is less than 2025 ohms, go to step 31).
  31. Check For VRS(-) Open Circuit (Resistance High Fault)  With ignition off and ECA disconnected, set DVOM on 20-k/ohm scale. Measure resistance between VRSS (32) and VRSE (48) at BOB. If resistance is less than 2025 ohms, replace VR sensor. Resistance is high. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test. If resistance is 2025 ohms or more, repair open circuit. VRS(-) circuit is open. Remove test equipment and reconnect all components. Clear Continuous Memory Codes and rerun Quick Test.
CAUTION: Never connect ECA to ECA BOB when performing EDIS diagnostics unless directed to do so.
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