Symptom Checks

Check the following items:

• On Pickups with Power Takeoff (PTO) and MIL concern, check PTO input to PCM. See TEST FB , step 3)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If MIL is always on when engine is running and no DTCs are present, check MIL circuits. On Continental, Expedition, Focus, F150, LS, Mustang, Navigator, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, see TEST NB under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If TCIL is always on when engine is running and no DTCs are present, check TCIL circuits. On Continental, Focus, LS, Mustang, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, see TEST TB , step 6)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If Malfunction Indicator Light (MIL) does not come on at all (including bulb check when engine is first started), check MIL circuits. On Continental, Expedition, Focus, F150, LS, Mustang, Navigator, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, see TEST NB , step 2)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If Transmission Control Indicator (TCIL) never comes on, check TCIL circuits. On Continental, Focus, LS, Mustang, Town Car or Windstar, see appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. On all other models, see TEST TB , step 8)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If temperature warning indicator light does not function properly, check cooling system or indicator light circuits. If engine overheats, check and repair cooling system as necessary. If cooling system operates at normal operating temperature, see TEST DL , step 40)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If SIL is always on or always off, check SIL circuits. See TEST KL under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If fuel cap indicator light is always on and no DTCs are present, check fuel cap indicator light circuits. See TEST HX , step 88)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If fuel cap indicator light is always off and no DTCs are present, check fuel cap indicator light circuits. See TEST HX , step 89)  under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article.
• If no problems are indicated, return to SYMPTOM DIAGNOSIS  to identify any additional symptoms or see TEST Z under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article and check for intermittent faults.