3.0L EFI

Use this test procedure ONLY when directed to do so by results of QUICK TEST  or steps in CIRCUIT TESTS  . Follow test procedure carefully.

1. When engine runs rough, misfires, stalls, or idles roughly, perform the following checks:
   • Perform SYSTEM CHECK, ISC Check. Use TEST SS - SYSTEM CHECK  , step 1).
   • Check MAP sensor, using TEST H - MAP SENSOR  , step 11).
   • Check EGR valve for correct function.
   • Check ignition components (cap, rotor, wires, coil, & plugs).
   • Check basic engine components (valves, cam timing, compression, etc.).
   • Check fuel delivery.
   • Check for, and repair, any bad ground or power connections.
2. If detonation (engine knock) occurs, go to TEST I - KNOCK SENSOR  , step 1).
3. If engine stalls while parking vehicle, go to TEST P - PSPS  , step 3).
4. If gasoline fumes accumulate in engine compartment, go to TEST Y - CANISTER PURGE (CANP) CHECK  , step 1).
5. If fuel pump always runs, go to TEST UU - IRCM  , step 13).
6. If engine cooling fan, or if low (high) speed engine cooling fans do not work, go to TEST UU - IRCM  , step 17).
7. If low (high) speed engine cooling fans work all the time, go to TEST UU - IRCM  , step 29).
8. If engine stumbles after hot restart (check HEGO), go to TEST UU - IRCM  , step 18).
9. If A/C does not work, go to TEST UU - IRCM  , step 39).
10. If A/C does not cut-off during wide open throttle (WOT), go to TEST UU - IRCM  , step 41).

Fig 1: 3.0L EFI EEC-IV Wiring Diagram (Taurus & Sable)