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Home >> Ford >> 2005 >> Focus ZX3 SES, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Test JE: Integrated Ignition Coil Pack A, B, Or C Failure Through Pinpoint Test KP: Charge Air Cooler (CAC) Pump - (Except Diesel & Hybrid) >> Pinpoint Test KE: Idle Air Control (IAC) Valve >> Test Procedure

Test Procedure

  1. KE1 DTCS P0505, P0506, P0511, P1504 OR P1507: CHECK FOR INLET AIR LEAKS. (OR STARTS ONLY AT PART THROTTLE) 
    • With the engine running at idle (if possible), listen for vacuum leaks.
    • Inspect the entire air intake system from the mass air flow (MAF) sensor to the intake manifold for leaks such as:
      • Damaged or loose IAC air tubes.
      • Cracked or punctured intake air tube.
      • Loose intake air tube at the air cleaner housing or throttle body.
      • IAC valve or gasket seal.
      • EGR valve gasket seal.
      • Vacuum supply connector and hose.
      • PCV valve, connectors and hoses.

    Are any leaks present? 

    Yes No
    Key in OFF position.
    REPAIR as necessary.    		 Key in OFF position.
    GO to  KE2.
  2. KE2 CHECK FOR VOLTAGE TO THE IAC SOLENOID 
    NOTE: If EGR DTC P0402 was output during the self-test, diagnose it first before continuing with this pinpoint test.
    • IAC connector disconnected.
    • Key in ON position.
    • Measure the voltage between:
      (+) IAC Connector, Harness Side (-) Vehicle Battery
      PWR Negative terminal

    Is the voltage greater than 10.5 volts? 

    Yes No
    Key in OFF position.
    GO to  KE3.    		 Key in OFF position. REPAIR the open circuit.
  3. KE3 CHECK THE RESISTANCE OF IAC VALVE 
    • IAC connector disconnected.
    • Measure the resistance between:
      (+) IAC Connector, Component Side (-) IAC Connector, Component Side
      PWR IAC

    Is the resistance between 6 ohms - 15 ohms? 

    Yes No
    GO to  KE4. INSTALL a new IAC valve.
  4. KE4 CHECK THE IAC VALVE FOR AN INTERNAL SHORT TO THE IAC CASE 
    • Measure the resistance between:
      (+) IAC Connector, Component Side (-) IAC Connector, Component Side
      IAC IAC Case

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KE5. INSTALL a new IAC valve.
  5. KE5 CHECK THE IAC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • IAC connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) IAC Connector, Harness Side (-) PCM Connector, Harness Side
      IAC IAC

    Is the resistance less than 5 ohms? 

    Yes No
    For IAC-RC applications
    GO to  KE6.
    For all others
    GO to  KE7.    		 REPAIR the open circuit.
  6. KE6 CHECK IAC-RC FOR VOLTAGE 
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-)
      IAC-RC Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KE7. REPAIR the open circuit.
  7. KE7 CHECK THE IAC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • Key in ON position.
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      IAC Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position.
    GO to  KE8.    		 Key in OFF position. REPAIR the short circuit.
  8. KE8 CHECK THE IAC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-)
      IAC Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KE9. REPAIR the short circuit.
  9. KE9 CHECK FOR A DROP IN IDLE RPM WITH THE IAC DISCONNECTED 
    • PCM connector connected.
    • IAC connector connected.
    • Key on engine running.
    • Bring the engine to normal operating temperature.
    • Transmission in PARK or NEUTRAL.
    • Disconnect the IAC Valve.

    Does the RPM drop or the engine stall? 

    Yes No
    Key in OFF position.
    GO to  KE11.    		 Key in OFF position.
    GO to  KE10.
  10. KE10 CHECK FOR STUCK IAC PINTLE 
    • Inspect the entire intake air system for debris, blockage or other damage.
    • Remove and inspect the IAC valve and check the pintle movement. Check the air tubes (if equipped) for blockage or damage.
    • Remove and inspect the air cleaner element for excessive dirt.

    Is the IAC valve OK? 

    Yes No
    GO to  KE11. INSTALL a new IAC valve.
  11. KE11 VERIFY THE DTC 

    Is DTC P0511 or P1504 present in continuous memory or from the KOER self-test? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . GO to  KE12.
  12. KE12 CHECK THE IAC SIGNAL FROM THE PCM 
    • PCM connector connected.
    • IAC connector connected.
      NOTE: If stalling occurs, place a shim under the hard stop screw to maintain idle conditions.
    • Key on engine running.
    • Access the PCM and monitor the RPM PID.
    • Access the PCM and monitor the IAC PID.
    • With the engine at normal operating temperature, closed throttle and all accessories off, the IAC duty cycle should be between approximately 22% and 65%.
    • Slowly increase the engine speed to 3, 000 RPM and return to closed throttle. (Note: If closed throttle RPM is significantly higher than normal, ignore this step).

    Is the duty cycle between 22% - 65%? 

    Yes No
    Key in OFF position.
    GO to  KE13.    		 Key in OFF position. INSTALL a new IAC valve.
  13. KE13 VERIFY THE DTC 

    Is DTC P0506, P0511, P1504 or P1507 present in Continuous Memory ? 

    Yes No
    GO to  KE19. Key in OFF position.
    INSPECT throttle body for damage. REPAIR as necessary. If OK, INSTALL a new IAC valve.
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
  14. KE14 DTCS P0507 OR P1506: CHECK FOR INLET AIR LEAKS 
    • Key on engine running.
    • With the engine running at idle, listen for vacuum leaks.
    • Inspect the entire air intake system from the mass air flow (MAF) sensor to the intake manifold for leaks such as:
      • Damaged or loose IAC air tubes.
      • Cracked or punctured intake air tube.
      • Loose intake air tube at the air cleaner housing or throttle body.
      • IAC valve or gasket seal.
      • EGR valve gasket seal.
      • Vacuum supply connector and hose.
      • PCV valve, connectors and hoses.

    Are any leaks present? 

    Yes No
    Key in OFF position.
    REPAIR as necessary.    		 Key in OFF position.
    GO to  KE15.
  15. KE15 CHECK FOR EVAP DTCS 
    NOTE: EVAP system malfunctions can cause IAC DTCs or idle speed concerns.

    Are any EVAP DTCs present ? 

    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. ADDRESS the next DTC. GO to POWERTRAIN DTC CHARTS AND DESCRIPTIONS - GASOLINE MODELS . GO to  KE16.
  16. KE16 CHECK THE IAC VALVE FOR CORRECT FUNCTION 
    • Key on engine running.
    • Bring the engine to normal operating temperature.
    • Transmission in PARK or NEUTRAL.
    • Disconnect the IAC Valve.

    Does the RPM drop or the engine stall? 

    Yes No
    Key in OFF position.
    GO to  KE17.    		 Key in OFF position.
    INSPECT throttle body for damage. REPAIR as necessary. If OK, INSTALL a new IAC valve.
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
  17. KE17 CHECK THE IAC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    NOTE: Refer to the POWERTRAIN CONTROL MODULE (PCM) CONNECTOR  pin numbers in the beginning of this pinpoint test.
    • Diagnostic tool connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      IAC Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KE18. REPAIR the short circuit to GND.
  18. KE18 VERIFY THE SYMPTOM 

    Is a fast idle symptom currently present? 

    Yes No
    INSTALL a new PCM. GO to  KE19.
  19. KE19 CHECK THE IAC SYSTEM FOR AN INTERMITTENT OPEN OR SHORT 
    • PCM connector connected.
    • Key on engine running.
    • Access the PCM and monitor the IAC and RPM PIDs.
    • With the engine at normal operating temperature, closed throttle and all accessories off, the IAC duty cycle should be between approximately 22% and 65%.
    • Observe the PIDs while completing the following at idle:
      • Lightly tap on the and wiggle the harness connector to simulate road shock.
      • Grasp the vehicle harness closest to the IAC valve. Shake and bend a small section of the harness from the IAC to the bulkhead and from the bulkhead to the PCM.

    Do the IAC or RPM PIDs suddenly change in value, indicating a fault? 

    Yes No
    Key in OFF position.
    ISOLATE the fault and REPAIR as necessary.    		 Key in OFF position.
    GO to  KE20.
  20. KE20 VERIFY THE SYMPTOM 

    Is an idle quality, starting or stalling symptom currently present? 

    Yes No
    INSTALL a new IAC valve. Concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS for further direction.
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