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Home >> Cadillac >> 2006 >> STS V >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 4.4L - DTC P0196 To P0496 >> DTC P0340 or P0345 >> Circuit/System Verification

Circuit/System Verification

  1. If DTCs P0641 or P0651 are set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
  2. With the engine running, observe the CMP Sensor parameter using the scan tool. The CMP sensor speed should match the Engine Speed parameter within 100 RPM.
    • If the CMP sensor speed is 0, continue with Circuit/System Testing.
  3. With the ignition ON and the engine OFF, use the Live Plot function on the scan tool. Select the Engine Speed parameter and the CMP Sensor parameter. Change the minimum spec to 0 RPM for both parameters. Change the maximum spec to 1,500 RPM for both parameters.
  4. Observe the scan tool and start the engine. The graphed lines should stay together.
    • If the CMP sensor line deviates excessively from the engine speed line, continue with Circuit/System Testing.
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