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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 759 (Engine Controls - Pinpoint Tests - Bi-Fuel CNG) >> Pinpoint Tests Ac: No Start/Hard Start In Alt Fuel - Alt Fuel Switch Indicator Is On Then Off >> Test Procedure

Test Procedure

WARNING: This page is about a different car, the 2004 Ford Pickup Heritage. However, it is still accessible from the selected car via links, so may be relevant.
  1. AC1 MONITOR THE FUEL RAIL PRESSURE AND FUEL TANK PRESSURE PIDS 
    NOTE: Verify the ALT fuel tank is filled.
    • Key off.
    • Connect the scan tool.
    • Place the ALT fuel switch in the ALT position.
    • Key on, engine off.
    • Access the AFCM.
    • Select the FRPREAB and TANKPR PIDS.

    Is The FRPREAB PID Greater Than 517 KPA (75 PSI) And The TANKPR PID Greater Than 3447 KPA (500 PSI)? 

    Yes No
    GO to  AC11. If the FRPREAB PID is less than 517 kPa (75 psi) and the TANKPR PID is greater than 1034 kPa (150 psi), GO to  AC2.
    If the FRPREAB PID is less than 517 kPa (75 psi) and the TANKPR PID is less than 1034 kPa (150 psi), GO to  AC9.
  2. AC2 CHECK THE FUEL RAIL SOLENOID 
    • Key off.
    • Disconnect the fuel rail solenoid C1405.
    • Key on, engine off.
    • Access the PCM.
    • Command the fuel pump on.
    • Measure the voltage between the fuel rail solenoid C1405 PWR circuit, harness side and the fuel rail solenoid C1405 ground circuit, harness side.

    Is The Voltage Greater Than 10 Volts? 

    Yes No
    GO to  AC12. GO to  AC3.
  3. AC3 CHECK THE FUEL RAIL SOLENOID GROUND CIRCUIT FOR AN OPEN 
    • Command the fuel pump off.
    • Key off.
    • Measure the resistance between the fuel rail solenoid C1405 ground circuit, harness side and ground.

    Is Resistance Less Than 5 Ohms? 

    Yes No
    GO to  AC4. REPAIR the circuit.
  4. AC4 CHECK THE ALT FUEL RELAY PIN 85 FOR VOLTAGE 
    • Key off.
    • Disconnect the ALT fuel relay C1293.
    • Key on, engine off.
    • Measure the voltage between the ALT fuel relay C1293 pin 85, harness side and ground.

    Is The Voltage Greater Than 10 Volts? 

    Yes No
    GO to  AC5. REPAIR the circuit.
  5. AC5 CHECK THE ALT FUEL RELAY PIN 30 FOR VOLTAGE 
    • Access the PCM.
    • Command the fuel pump on.
    • Measure the voltage between the ALT fuel relay C1293 pin 30, harness side and ground.

    Is The Voltage Greater Than 10 Volts? 

    Yes No
    GO to  AC6. REPAIR the circuit.
  6. AC6 CHECK THE ALT FUEL RELAY CONTROL CIRCUIT FOR AN OPEN 
    • Command the fuel pump off.
    • Key on, engine off.
    • Measure the resistance between the ALT fuel relay C1293 pin 86, harness side and ground.

    Is The Resistance Less Than 5 Ohms? 

    Yes No
    GO to  AC8. GO to  AC7.
  7. AC7 CHECK THE AFCM FOR AN INTERNAL OPEN 
    • Key off.
    • Disconnect the AFCM C1404.
    • Measure the resistance between the ALT fuel relay C1293 pin 86, harness side and the AFCM pin 26, harness side.

    Is The Resistance Less Than 5 Ohms? 

    Yes No
    GO to  AC11. REPAIR the circuit.
  8. AC8 CHECK THE FUEL SOLENOID PWR CIRCUIT FOR AN OPEN 
    • Measure the resistance between the ALT fuel relay C1293 pin 87, harness side and the fuel rail solenoid C1405 PWR circuit, harness side.

    Is The Resistance Less Than 5 Ohms? 

    Yes No
    INSTALL a new ALT fuel relay. REPAIR the circuit.
  9. AC9 CHECK THE FUEL TANK SOLENOID 
    • Key off.
    • Disconnect the fuel tank solenoid C3234.
    • Key on, engine off.
    • Access the PCM.
    • Command the fuel pump on.
    • Measure the voltage between the fuel tank solenoid C3234 PWR circuit, harness side and the fuel tank solenoid C3234 ground circuit, harness side.

    Is The Voltage Greater Than 10 Volts? 

    Yes No
    INSTALL a new fuel tank solenoid. GO to  AC10.
  10. AC10 CHECK THE FUEL TANK SOLENOID GROUND CIRCUIT FOR AN OPEN 
    • Command the fuel pump off.
    • Key off.
    • Measure the resistance between the fuel tank solenoid C3234 ground circuit, harness side and ground.

    Is The Resistance Less Than 5 Ohms? 

    Yes No
    REPAIR the fuel tank solenoid PWR circuit. REPAIR the fuel tank solenoid ground circuit.
  11. AC11 CHECK FOR CORRECT AFCM OPERATION 
    • Disconnect the AFCM.
    • Check for:
      • corrosion
      • pushed out pins
    • Connect the AFCM connector and make sure it is seated correctly.
    • Operate the system and verify the concern is still present.

    Is The Concern Still Present? 

    Yes No
    INSTALL a new AFCM. The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
  12. AC12 CHECK THE FUEL PRESSURE REGULATOR 
    • Key off.
    WARNING: BEFORE PERFORMING THE FOLLOWING TEST, GO to Pinpoint Test HC  AND FOLLOW THE FUEL SYSTEM DEPRESSURIZATION PROCEDURE. READ ALL WARNINGS, CAUTIONS, AND NOTES IN PINPOINT TEST HC.
    • Depressurize the ALT fuel system. Refer to FUEL SYSTEM - GENERAL INFORMATION .
    • Disconnect the fuel pressure regulator inlet and outlet lines.
    • Apply a regulated source of pressurized air to the fuel pressure regulator inlet side.
    • Listen for air escaping from the outlet side.

    Is Pressurized Air Escaping From The Outlet Side? 

    Yes No
    INSTALL a new fuel rail solenoid. INSTALL a new fuel pressure regulator.
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