LEMON Manuals: Even more car manuals for everyone
Home >> Mercury >> 2005 >> Montego Base, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test DK: Accelerator Pedal Position Sensor Through Pinpoint Test DX: Engine Coolant Temperature (ECT) Sensor - (Except Diesel & Hybrid) >> Pinpoint Test DR: Camshaft Position (CMP) Sensor >> Test Procedure

Test Procedure

  1. DR1 CONTINUOUS MEMORY DTCS P0340, P0344, P0345 AND P0349: CHECK IF THE ENGINE WILL START 
    • Attempt to start the engine.

    Does the engine start? 

    Yes No
    GO to  DR2. Concern is elsewhere. RETURN to SYMPTOM CHARTS for further direction.
  2. DR2 CLEAR AND ATTEMPT TO RETRIEVE THE DTC 
    NOTE: For vehicles with variable camshaft timing (VCT), concerns with the engine oil level, oil filter, oil contamination, or the VCT system may cause camshaft positioning errors.
    • Key ON, engine OFF.
    • Clear the PCM DTCs.
    • Key ON, engine running.
    • Increase engine speed to greater than 1,500 RPM for 10 seconds. Repeat this 3 times.
    • Retrieve the continuous memory DTCs.

    Are DTCs P0340, P0344, P0345 or P0349 present? 

    Yes No
    For continuous memory DTCs P0340 and P0344, GO to  DR3
    For continuous memory DTCs P0345 and P0349, GO to  DR11    		 GO to
  3. DR3 DETERMINE THE CMP SENSOR PHYSICAL TYPE 
    • Key in OFF position.

    Is the CMP sensor a synchronizer (gear driven) type? 

    Yes No
    GO to  DR4. GO to  DR5.
  4. DR4 VERIFY THE CORRECT INSTALLATION OF THE CMP SENSOR 
    • A CMP sensor identifies the cylinder 1 power stroke. A sensor that is improperly installed/indexed can identify the wrong cylinder as 1, produce a tip-in hesitation and generate a DTC.
      NOTE: If the vehicle has a miss with DTC P0340 or P0344, ignition, alternator noise, RFI and CKP concerns should be considered.

    Is the CMP sensor installed correctly? 

    Yes No
    GO to  DR5. INSTALL the CMP sensor correctly. REFER to the appropriate ELECTRONIC ENGINE CONTROLS for additional information.
  5. DR5 DETERMINE THE CMP SENSOR ELECTRONIC TYPE 
    NOTE: The variable reluctance (VR) sensors have 2-wire connectors, Hall-effect sensors have 3-wire connectors.

    Is the CMP sensor a VR-type? 

    Yes No
    Key in OFF position.
    GO to  DR6.    		 The CMP sensor is a Hall-effect type.
    GO to  DR17.
  6. DR6 CONTINUOUS MEMORY DTCS P0340 AND P0344: CHECK THE CMP SENSOR RESISTANCE 
    • CMP Sensor connector disconnected.
    • Measure the resistance between:
      (+) CMP Sensor Connector, Component Side (-) CMP Sensor Connector, Component Side
      CMP SIGRTN
      Vehicle Low Limit High Limit
      LS, Thunderbird 3.9L 1, 850 Ohms 2, 850 Ohms
      F-150 300 Ohms 425 Ohms
      All others 250 Ohms 1, 000 Ohms

    Is the resistance within specification? 

    Yes No
    GO to  DR7. INSTALL a new CMP sensor correctly.
    Clear the PCM DTCs. REPEAT the self-test.
  7. DR7 CHECK THE CMP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      (+) CMP Sensor Connector, Harness Side (-) Vehicle Battery
      CMP Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position.
    GO to  DR8.    		 REPAIR the short circuit.
  8. DR8 CHECK THE CMP CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) CMP Sensor Connector, Harness Side
      CMP CMP
      SIGRTN SIGRTN

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  DR9. REPAIR the open circuit.
  9. DR9 CHECK FOR A SHORT IN THE HARNESS BETWEEN THE PCM AND THE CMP SENSOR 
    • Measure the resistance between:
      (+) CMP Sensor Connector, Harness Side (-) CMP Sensor Connector, Harness Side
      CMP SIGRTN
    • Measure the resistance between:
      (+) CMP Sensor Connector, Harness Side (-) Vehicle Battery
      CMP Negative terminal
      SIGRTN Negative terminal

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DR10. REPAIR the short circuit.
  10. DR10 CHECK THE CMP SENSOR OUTPUT 
    • PCM connector connected
    • CMP Sensor connector disconnected.
    • Digital multimeter on low voltage AC scale.
    • Measure the voltage between:
      (+) CMP Sensor Connector, Component Side (-) CMP Sensor Connector, Component Side
      CMP SIGRTN
    • Run the engine at approximately 2,500 RPM.

    Is the voltage greater than 0.25 V? 

    Yes No
    For Expedition, F-150 5.4L, Mustang 4.6L, and Navigator, GO to  DR24
    For all others, INSTALL a new PCM.    		 INSTALL a new CMP sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS .
  11. DR11 CONTINUOUS MEMORY DTCS P0345 AND P0349: CHECK THE CMP2 SENSOR RESISTANCE 
    • Key in OFF position.
    • CMP2 Sensor connector disconnected.
    • Measure the resistance between:
      (+) CMP2 Sensor Connector, Component Side (-) CMP2 Sensor Connector, Component Side
      CMP2 SIGRTN
      Vehicle Low Limit High Limit
      LS, Thunderbird 3.9L 1,850 Ohms 2,850 Ohms
      F-150 300 Ohms 425 Ohms
      All others 250 Ohms 1, 000 Ohms

    Is the resistance value(s) within specifications? 

    Yes No
    GO to  DR12. INSTALL a new CMP2 sensor. Clear the DTCs. REPEAT the self-test.
  12. DR12 CHECK THE CMP2 CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      (+) CMP2 Sensor Connector, Harness Side (-) Vehicle Battery
      CMP2 Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position.
    GO to  DR13.    		 REPAIR the short circuit.
  13. DR13 CHECK THE CMP2 CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) CMP2 Sensor Connector, Harness Side
      CMP2 CMP2
      SIGRTN SIGRTN

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  DR14. REPAIR the open circuit.
  14. DR14 CHECK FOR A SHORT IN THE HARNESS BETWEEN THE PCM AND THE CMP2 SENSOR 
    • Measure the resistance between:
      (+) CMP2 Sensor Connector, Harness Side (-) CMP2 Sensor Connector, Harness Side
      CMP2 SIGRTN
    • Measure the resistance between:
      (+) CMP2 Sensor Connector, Harness Side (-) Vehicle Battery
      CMP2 Negative terminal
      SIGRTN Negative terminal

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DR15. REPAIR the short circuit.
  15. DR15 CHECK FOR A SHORT BETWEEN THE CMP AND THE CMP2 CIRCUITS 
    • CMP Sensor connector disconnected.
    • CMP2 Sensor connector disconnected.
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
      CMP CMP2

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DR16. REPAIR the short circuit.
  16. DR16 CHECK THE CMP2 SENSOR OUTPUT 
    • PCM connector connected.
    • Digital multimeter on low voltage AC scale.
    • Measure the voltage between:
      (+) CMP2 Sensor Connector, Component Side (-) CMP2 Sensor Connector, Component Side
      CMP2 SIGRTN
    • Run the engine at approximately 2,500 RPM.

    Is the voltage greater than 0.25 V? 

    Yes No
    For Expedition, F-150 5.4L, Mustang 4.6L, and Navigator, GO to  DR24.
    For all others, INSTALL a new PCM.    		 INSTALL a new CMP2 sensor.
  17. DR17 CONTINUOUS MEMORY DTCS P0340 AND P0344: CHECK THE VPWR VOLTAGE TO CMP SENSOR 
    • CMP Sensor connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      (+) CMP Sensor Connector, Harness Side (-) Vehicle Battery
      VPWR Negative terminal

    Is the voltage greater than 10.5 V? 

    Yes No
    Key in OFF position. GO to  DR18. Key in OFF position. REPAIR the open circuit.
  18. DR18 CHECK THE PWRGND VOLTAGE TO CMP SENSOR 
    • Measure the voltage between:
      (+) Vehicle Battery (-) CMP Sensor Connector, Harness Side
      Positive terminal PWRGND

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  DR19. REPAIR the open circuit.
  19. DR19 CHECK THE CMP CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      (+) CMP Sensor Connector, Harness Side (-) Vehicle Battery
      CMP Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    Key in OFF position. GO to  DR20. REPAIR the short circuit.
  20. DR20 CHECK FOR AN OPEN CIRCUIT BETWEEN THE PCM AND CMP SENSOR 
    • CMP Sensor connector disconnected.
    • Measure the resistance between:
      (+) CMP Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      CMP CMP

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DR21. REPAIR the open circuit.
  21. DR21 CHECK THE CMP SENSOR CIRCUIT FOR A SHORT TO GND IN THE HARNESS 
    NOTE: The measurement may be taken at the PCM or CMP connector, whichever is easier to access.
    • Measure the resistance between:
      (+) CMP Sensor Connector, Harness Side (-) CMP Sensor Connector, Harness Side
      CMP PWRGND

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DR22. REPAIR the short circuit.
  22. DR22 CHECK FOR SHORTS IN THE PCM 
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
      CMP
      CMP      		 VPWR
      PWRGND

    Are the resistances greater than 500 ohms? 

    Yes No
    GO to  DR23. INSTALL a new PCM.
  23. DR23 CHECK THE CMP SENSOR OUTPUT DURING CRANK MODE 
    • CMP Sensor connector connected.
    • Digital multimeter on low voltage DC scale
    • Measure the voltage between:
    (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
    CMP PWRGND

    Crank the engine for at least 10 revolutions.

    Does the voltage switch between LOW (less than 2 volts DC) and HIGH (greater than 8 volts DC)?

    Yes No
    Install a new PCM. Install a new CMP sensor.
  24. DR24 CHECK FOR CORRECT PCM OPERATION 
    NOTE: Only diagnose the bank indicated by the DTC
    • Check the VCT system for correct operation.

    Is a concern present? 

    Yes No
    REPAIR as necessary. INSTALL a new PCM.
scientia non olet · About LEMON Manuals