FixVault
Home › Cadillac › 2007 › STS V › Repair and Diagnosis › Engine Performance › System › Engine Controls And Fuel - 4.4L - DTC P0010 To DTC P0158 › DTC P012B › Circuit/System Verification

Circuit/System Verification

  1. If DTCs P0102, P0103, P0106, P0107, P0108, P0121, P0641, P0651, P2228, or P2229 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further information.
  2. Ignition OFF, verify the integrity of the entire supercharger air induction system, inspecting for the air induction system for the following conditions:
    • A restricted or collapsed air intake duct
    • A misaligned or damaged air intake duct
    • A dirty or deteriorating air filter element
    • Any objects blocking the air inlet probe of the MAF/IAT sensor
    • Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor
    • Any water intrusion in the induction system
    • Any vacuum leak downstream of the MAF/IAT sensor
    • An intake manifold leak
    • A BARO sensor that is skewed or stuck
  3. Inspect the vacuum lines for cracking, loose fit, or for improper routing at the following locations:
    • The SCIAP sensor
    • The MAP sensor
    • The by-pass valve solenoid
    • The by-pass valve actuator
  4. Inspect the by-pass valve and cable for any of the following conditions:
    • Sticking in either the open or closed position
    • Binding when opening or closing
    • Incorrectly adjusted cable
    • Any damage
  5. Ignition ON, observe the MAP and SC Inlet Pressure Sensor kPa parameters with a scan tool. Start the engine and let it idle. The MAP and SC Inlet Pressure Sensor kPa parameters should decrease and closely match each other.
    • If the MAP Sensor kPa parameter does not decrease, refer to DTC P0106 .
  6. Ignition ON, depress the accelerator pedal completely and observe the TP Indicated Angle parameter with a scan tool. The TP Indicated Angle parameter should read 98-100 percent.
  7. Ignition ON, perform a snapshot of the throttle actuator control (TAC) data while performing the following action. Refer to Scan Tool Snapshot Procedure .
    1. Slowly depress the accelerator pedal to WOT position and then slowly release the pedal. Exit from the snapshot and review the data.
    2. Compare the TP Sensor 1 and the TP Sensor 2 parameters, frame by frame. The difference between the parameters should be less than 4 percent.
    8. CAUTION: Refer to Road Test Caution .
  8. Engine running, on a road test perform a brief wide open throttle (WOT) acceleration from 30 mph. The MAP sensor parameter on the scan tool should increase rapidly. This increase should be from approximately 35 kPa at idle to greater than 135 kPa.
  9. Engine running, observe the DTC information with a scan tool. DTC P012B should not set.
  10. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
About FixVault