Diagnostic Aids

Enter this test only when all steps under QUICK TEST have been successfully completed and engine still does not start or if directed here from another test or chart. This test is only intended to diagnose:

• Powertrain Control Module (PCM).
• Spark (PCM-controlled).

To prevent replacement of good components, be aware the following non-EEC related areas and components may be cause of problem:

• Fuel quality and quantity.
• Ignition (general condition).
• Engine mechanical components.
• Starter and battery circuits.

1. 1) Check Anti-Theft System
   
   If vehicle does not have a anti-theft system, go to next step. If vehicle has an anti-theft system, it may be activated causing the no-start condition. Verify be observing anti-theft indicator light on instrument panel or a DTC P1260 may be present. If anti-theft system is not activated, go to next step. If anti-theft system is activated, see appropriate ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT for diagnosis and testing.
2. 2) Attempt To Crank Engine
   
   Ensure Inertia Fuel Shutoff (IFS) switch is closed (button pushed in). Try to start engine. If engine does not crank, check vehicle starting and charging systems. Repair as necessary and retest. If engine cranks, go to next step.
3. 3) Check For Intermittent
   
   Attempt to start engine. If engine now starts, fault is intermittent. Go to  TEST Z, step 50). If engine does not start, go to  TEST HA, step 47) (Natural Gas vehicles) or next step (all others).
4. 4) Check VREF At TP Sensor
   
   Turn ignition off. Disconnect TP sensor. Turn ignition on. Measure voltage between circuits VREF and SIG RTN at TP sensor wiring harness connector. See Fig 1 or Fig 2 . If voltage is 4-6 volts, reconnect TP sensor connector and go to next step. If voltage is not 4-6 volts, go to TEST C .
   Fig 1: Identifying TP Sensor Circuits & Connector Terminals (Contour 2.0L, Cougar 2.0L & Mystique 2.0L)

   Courtesy of FORD MOTOR CO.
   Fig 2: Identifying TP Sensor Circuits & Connector Terminals (Except Contour 2.0L, Cougar 2.0L & Mystique 2.0L)

   Courtesy of FORD MOTOR CO.
5. 5) Check Flash EPROM (FEPS) Circuit For Short To Power
   
   Measure voltage between ground and DLC terminal No. 13. See Figure. If voltage is less than 9 volts, go to step  17) (models with coil-on-plug) or next step (models with coil pack). If voltage is 9 volts or more, repair circuit for a short to power.
6. 6) Check PIP Parameter Identifications (PID)
   
   Using scan tool, select PIP PID from PID/DATA monitor menu. While observing scan tool, crank engine. If PIP value is switching on and off, check secondary ignition components (ignition coils, spark plugs and wires). See TEST JB . Repair as necessary. If secondary ignition is okay, go to step  15) (Natural Gas vehicles) or next step (all others).
7. 7) Check Fuel Pressure
   
   Turn ignition off. Release fuel pressure. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Install fuel pressure gauge. With scan tool connected, turn ignition on. Using scan tool, access OUTPUT TEST MODE. See ADDITIONAL SYSTEM FUNCTIONS . Command fuel pump ON. If fuel pressure is as specified, go to next step. See FUEL PRESSURE SPECIFICATIONS . If fuel pressure is not as specified, go to TEST HC .
8. 8) Check Fuel Pressure Leakdown
   
   Leave fuel pressure gauge installed and ignition on. Using scan tool, access OUTPUT TEST MODE. Command fuel pump ON to obtain maximum fuel pressure. Exit OUTPUT TEST MODE and turn ignition off. If fuel pressure remains within 2.3 psi (16 kPa) of maximum pressure for one minute after turning ignition off, go to next step. If fuel pressure does not remain within 2.3 psi (16 kPa), go to TEST HC .
NOTE: A no-start condition can only occur if more than 50 percent of fuel injectors are without power.
9. 9) Check VPWR Circuit At Fuel Injectors
   Disconnect at least 2 fuel injector connectors. Turn ignition on. Measure voltage of VPWR circuit at disconnected fuel injector connectors. If voltage is more that 10.5 volts, go to next step. If any measure is 10.5 volts or less, repair VPWR circuit.
10. 10) Check Fuel Injectors
    
    Turn ignition off. Release fuel pressure. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Install fuel pressure gauge. Disconnect Inertia Fuel Shutoff (IFS) connector. Turn ignition on and off several times. Monitor fuel pressure gauge while cranking engine for at least 5 seconds. If fuel pressure drops more than 5 psi (kPa), engine control system is not cause of no-start. Diagnose by symptom. Go to TROUBLE SHOOTING - NO CODES - EEC-V article. If fuel pressure does not drop more than 5 psi (kPa), replace PCM.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 10) to step 15). No test procedures have been omitted.
11. 15) Check Fuel Pressure (Natural Gas Vehicles)
    
    Turn ignition off. Release fuel pressure. See REMOVAL, OVERHAUL & INSTALLATION - NATURAL GAS VEHICLES article. With scan tool connected to DLC, access FRP PID. Turn ignition on and record fuel pressure. If fuel pressure is 80-120 psi (552-827 kPa), go to next step. If fuel pressure is not 80-120 psi (590-800 kPa), go to TEST HB .
12. 16) Check Injector Signal From Natural Gas (NG) Module
    
    Turn ignition off. Connect a 12-volt test light between injector signal circuit and VPWR circuit terminal at fuel injector connector. Crank engine while observing test light. If test light glows dimly while cranking engine, replace PCM and go to step  6). If test light does not glow as specified, go to  TEST HA, step 47).
13. 17) Check PCM Driver To Coils
    
    Turn ignition off. Connect 12-volt test light between B+ and coil driver circuit. Crank engine while observing test light. Repeat procedure for each coil driver. Test light should blink brightly, once for each engine revolution. If test light blinks as specified, go to step  6). If test light does not blink as specified, go to TEST JD .