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Home >> Ford >> 2006 >> Focus ZX4 SE, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test HY: Generator/Regulator System Through Pinpoint Test KD: Electric Exhaust Gas RECIRCULATION (EEGR) System - (Except Diesel & Hybrid) >> Pinpoint Test JH: Tachometer Signal Output (CTO) >> Test Procedure
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Test Procedure

  1. JH1 CHECK THE CTO SIGNAL FROM THE PCM 
    NOTE: Refer to the appropriate SYSTEM WIRING DIAGRAMS for module and connector locations.
    • Disconnect the instrument cluster harness connector.
    • PCM connector connected.
    • Key ON, engine running.
    • Measure the voltage between the instrument cluster CTO circuit, harness side and battery negative terminal.

    Is the voltage between 3 and 9 volts? 

    Yes No
    REFER to appropriate INSTRUMENT CLUSTER article to continue diagnosis on the circuitry for the CTO. GO to  JH2.
  2. JH2 CHECK THE CTO CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      CTO VPWR
      CTO VREF

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  JH3. REPAIR the short circuit to PWR.
    CLEAR the DTCs. REPEAT the self-test.
  3. JH3 CHECK THE CTO CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      CTO PWRGND
      CTO SIGRTN

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  JH4. REPAIR the short circuit to GND.
    CLEAR the DTCs. REPEAT the self-test.
  4. JH4 CHECK THE CTO CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Check the CTO circuit resistance.

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  JH5. REPAIR the open circuit.
    CLEAR the DTCs. REPEAT the self-test.
  5. JH5 CHECK THE CTO CIRCUIT FOR INTERMITTENT CONCERNS 
    • Lightly tap on the CTO and wiggle the harness connector to simulate road shock.
    • Measure the CTO resistance between the PCM and the instrument cluster.

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  JH6. REPAIR the open circuit.
    CLEAR the DTCs. REPEAT the self-test.
  6. JH6 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 and 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.
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