LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2013 >> C-Max Energi >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Tests (Hybrid) >> Pinpoint Test Dg: Knock Sensor (KS) >> Test Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Procedure

  1. DG1 PRELIMINARY DIAGNOSIS 
    NOTE: An incorrectly installed KS may set a DTC. Verify the KS is correctly installed before continuing diagnosis. REFER to the appropriate Electronic Engine Controls article

    Is DTC P0325 or P0330 present? 

    Yes No
    GO to DG2  . For symptoms without DTCs, GO to DG2  .
    For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. DG2 CHECK THE SENSOR RESISTANCE 
    NOTE: Only measure the circuits that apply to the sensor being diagnosed.
    • Ignition OFF.
    • For KS1,
    • KS1 connector disconnected.
    • Measure the resistance between:
      (+) KS1 Connector, Component Side (-) KS1 Connector, Component Side
      KS1- - Pin 1 KS1+ - Pin 2
    • For KS2,
    • KS2 connector disconnected.
    • Measure the resistance between:
      (+) KS2 Connector, Component Side (-) KS2 Connector, Component Side
      KS2- - Pin 1 KS2+ - Pin 2

    Is the resistance between 4.63 - 5.11 Mohms? 

    Yes No
    GO to DG3  . INSTALL a new KS. REFER to the appropriate Electronic Engine Controls article
    Clear the PCM DTCs. REPEAT the self-test.
  3. DG3 CHECK FOR AN OPEN 
    NOTE: Only measure the circuits that apply to the sensor being diagnosed.
    • PCM connector disconnected.
    • For KS1,
    • Measure the resistance between:
      (+) KS1 Connector, Harness Side (-) PCM Connector, Harness Side
      KS1- - Pin 1 KS1- - Pin T25
      KS1+ - Pin 2 KS1+ - Pin T17
    • For KS2,
    • Measure the resistance between:
      (+) KS2 Connector, Harness Side (-) PCM Connector, Harness Side
      KS2- - Pin 1 KS2- - Pin T28
      KS2+ - Pin 2 KS2+ - Pin T20

    Are the resistances less than 5 ohms? 

    Yes No
    GO to DG4  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  4. DG4 CHECK FOR A SHORT TO GROUND 
    NOTE: Only measure the circuits that apply to the sensor being diagnosed.
    • For KS1,
    • Measure the resistance between:
      (+) KS1 Connector, Harness Side (-)
      KS1- - Pin 1 Ground
      KS1+ - Pin 2 Ground
    • For KS2,
    • Measure the resistance between:
      (+) KS2 Connector, Harness Side (-)
      KS2- - Pin 1 Ground
      KS2+ - Pin 2 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to DG5  . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  5. DG5 CHECK FOR A SHORT TO VOLTAGE 
    NOTE: Only measure the circuits that apply to the sensor being diagnosed.
    • Ignition ON, engine OFF.
    • For KS1,
    • Measure the voltage between:
      (+) KS1 Connector, Harness Side (-)
      KS1- - Pin 1 Ground
      KS1+ - Pin 2 Ground
    • For KS2,
    • Measure the voltage between:
      (+) KS2 Connector, Harness Side (-)
      KS2- - Pin 1 Ground
      KS2+ - Pin 2 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to DG6  .
  6. DG6 INTERMITTENT CHECK 
    NOTE: Only measure the circuits that apply to the sensor being diagnosed.
    • Ignition OFF.
    • While observing the resistance, wiggle, shake, and bend small sections of the wiring harness working from the sensor to the PCM.
    • For KS1,
    • Measure the resistance between:
      (+) KS1 Connector, Harness Side (-) PCM Connector, Harness Side
      KS1- - Pin 1 KS1- - Pin T25
      KS1+ - Pin 2 KS1+ - Pin T17
    • For KS2,
    • Measure the resistance between:
      (+) KS2 Connector, Harness Side (-) PCM Connector, Harness Side
      KS2- - Pin 1 KS2- - Pin T28
      KS2+ - Pin 2 KS2+ - Pin T20

    Are the resistances less than 5 ohms? 

    Yes No
    INSPECT connectors for signs of damage, water intrusion, corrosion. REPAIR as necessary.
    If no concern is present, RECONNECT the KS and PCM connectors.
    GO to DG7  .    		 REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.
  7. DG7 IDENTIFY THE CAUSE OF KNOCK 
    NOTE: Knock on a single cylinder may indicate a concern with the ignition or fuel components for the suspect cylinder. Knock distributed among multiple cylinders may indicate a fuel quality concern.
    • Check the ignition system for concerns.
    • Check the fuel delivery system for concerns.
    • Check the fuel injection components for concerns.

    Is a concern present? 

    Yes No
    DIAGNOSE the ignition system, fuel delivery system and fuel injection components for the suspect cylinder. REPAIR or INSTALL a new component as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DG8  .
  8. DG8 CHECK THE FUEL QUALITY 
    • Verify the fuel level, grade and quality is sufficient to support normal operation of the engine.

    Is a concern present? 

    Yes No
    DRAIN and CLEAN the fuel system, REFILL with correct grade fuel.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DG9  .
  9. DG9 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
scientia non olet · About LEMON Manuals