LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 1985 >> LTD LX >> Repair and Diagnosis >> Engine Performance >> System >> 5.0L CFI Tests >> Testing >> Test X - Air Management System

Test X - Air Management System

  1. Codes 44 (94), 45 (95) and 46 (96) Displayed. Ensure correct vacuum line routing to TAB/TAD solenoids and by-pass diverter valve. Refer to VECI decal for schematic. Check for kinked or blocked vacuum lines. Check for kinked or blocked air hoses. Check for disconnected vacuum lines. If problems are detected, correct hose routing, repair faults and repeat QUICK TEST. If hoses are good and code 44 (94) is displayed, go to step 4). If code 46 (96) is displayed, go to step 3). If code 45 (95) is displayed, go to next step.
  2. Code 45 (95) Displayed. This test ONLY applies to models equipped with TAD. Disconnect and plug vacuum line at diverter valve. Turn key OFF and wait 10 seconds. Repeat Engine Running Self-Test and record codes. If code 45 (95) is displayed, EEC-IV system is good. Check diverter valve and/or check valve for problem. If no code 45 (95) is displayed, go to step 4).
  3. Code 46 (96) Displayed. This test ONLY applies to models equipped with TAB. Disconnect and plug vacuum line at by-pass valve. Turn key OFF and wait 10 seconds. Repeat Engine Running Self-Test and record codes. If code 46 (96) is displayed, EEC-IV system is good. Check by-pass valve for problem. If no code 46 (96) is displayed, go to next step.
  4. Use only VOM/DVOM, not STAR tester, for this step. Turn key OFF and wait 10 seconds. With DVOM on 20 volt scale, connect negative test lead to STO and positive test lead to battery positive terminal. Using jumper wire, connect STI to signal return. Perform KOEO Self-Test until completion of Continuous Test codes. DVOM will indicate 0 volts. Depress and release throttle, DVOM reading should change to a high voltage reading. If reading changed, remain in Output State mode and go to next step. If reading did not change, depress throttle to WOT and release. If STO voltage does not go high, go to TEST NN  , step 13). Leave test equipment hooked up.
  5. With DVOM on 20 volt scale, connect DVOM positive test lead to VPWR circuit on TAB solenoid and negative test lead to TAB output circuit. While observing DVOM depress and release throttle several times to cycle output ON and OFF. Repeat for TAD solenoid. Connect positive test lead to VPWR circuit on TAD solenoid and negative test lead to TAD output circuit. Cycle output ON and OFF. If either output does not cycle ON and OFF, remove jumper and go to step 8). If both outputs cycle ON and OFF, go to next step.
  6. Connect vacuum pump to TAB solenoid vacuum supply port. Connect vacuum gauge to output port. Maintain vacuum at source while depressing and releasing throttle to cycle output ON and OFF. Observe vacuum gauge. Repeat for TAD solenoid. If either solenoid does not cycle ON and OFF, replace solenoid assembly and repeat QUICK TEST. If both solenoids cycle ON and OFF, go to next step.
  7. With vacuum lines disconnected at TAB/TAD solenoid assembly, start engine and check for vacuum. If vacuum is present, EEC-IV system is good. Check thermactor valve and air pump for problem. If no vacuum is present, repair blockage as required and repeat QUICK TEST.
  8. Turn key OFF, wait 10 seconds and place DVOM on 200 ohm scale. Disconnect TAB and TAD solenoid connectors. Measure solenoid resistances. If either reading is less than 50 ohms or more 100 ohms, replace TAB/TAD solenoid assembly and repeat QUICK TEST. If both readings are between 50-100 ohms, connect TAB/TAD solenoids and go to next step.
  9. Turn key ON, leaving engine OFF. Set DVOM on 20V scale. Measure voltage between VPWR circuit and ground on TAB connector. Repeat for TAD solenoid. If either voltage reading is less than 10.5 volts repair harness circuit open and repeat QUICK TEST. If both readings are greater than 10.5 volts, go to next step.
  10. Turn key OFF and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Connect breakout box to harness and leave ECA disconnected. With DVOM on 200 ohm scale, measure resistance between test pin 51 and TAB circuit at harness connector. Measure resistance between pin 11 and TAD circuit at harness connector. If either reading is 5 ohms or greater, repair harness open circuit and repeat QUICK TEST. If both readings are less than 5 ohms, go to next step.
  11. Turn key OFF and wait 10 seconds. Set DVOM on 200,000 ohm scale. Leave breakout box installed and ECA disconnected. Disconnect TAB/TAD solenoids and measure resistance between test pins 51 and/or 11 and test pins 37 and 57. If reading is less than 10,000 ohms, repair short to power and repeat QUICK TEST. If reading is greater than 10,000 ohms, go to next step.
  12. Turn key OFF and wait 10 seconds. Set DVOM on 200,000 ohm scale. Leave breakout box installed and ECA disconnected. Disconnect TAB/TAD solenoids and measure resistance between test pins 51 and/or 11 and test pins 40, 46 and 60. If reading is less than 10,000 ohms, repair circuit short. Remove breakout box, reconnect harness to ECA and repeat QUICK TEST. If code is repeated, replace ECA. If reading is 10,000 ohms or more, replace ECA. Remove breakout box, connect harness to ECA and repeat QUICK TEST.
Fig 1: Air Management Circuit
G2565
scientia non olet · About LEMON Manuals