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Home >> Chevrolet >> 2012 >> Traverse LS, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls/Fuel - 3.6L - DTC P0010 To DTC P0338 >> Diagnostic Information and Procedures >> DTC P0068 or P1101 >> Circuit/System Testing

Circuit/System Testing

  1. Verify none of the following conditions exist:
    • The air intake duct system for loose clamps, cracks, or other damage
    • The air intake duct system for being collapsed or restricted
    • Restricted air filter
    • Q38 throttle body for dirt, debris, and coking. Also, throttle body blade or shaft damage. Refer to Throttle Body Inspection and Cleaning for further diagnosis.
    • Splits, kinks, or improper connections at the vacuum hoses
    • Missing, restricted, or leaking exhaust components-Refer to Symptoms - Engine Exhaust for further diagnosis.
    • Vacuum leaks at the intake manifold and Q38 throttle body.
    • If a condition exists, repair as necessary.
  2. Ignition ON, observe the diagnostic trouble code (DTC) information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 is not set.
  3. Determine the current vehicle testing altitude. Compare the MAP Sensor pressure parameter to the reading in the Altitude Versus Barometric Pressure table. The MAP sensor pressure parameter should be within the specified range indicated in the table.
    • If the MAP sensor pressure is not within the range specified for your altitude, refer to DTC P0106  for DTC P0106.
  4. Engine idling, observe the MAP Sensor kPa parameter. The reading should be between 26-52 kPa (3.8-7.5 psi).
    • If not within the specified range, refer to DTC P0106  for further diagnosis.
  5. Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 2.5-8.8 g/s depending on the engine coolant temperature (ECT) and barometric (BARO) pressure.
    • If not within the specified range, refer to DTC P0101  for further diagnosis.
  6. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.
    1. Engine idling
    2. Perform the scan tool snapshot function.
    3. Increase the engine speed slowly to 3,000 RPM and then back to idle.
    4. Exit from the scan tool snapshot and review the data.
    5. Observe the MAF Sensor parameter frame by frame with a scan tool.
    • If the MAF Sensor g/s parameter does not change smoothly and gradually, refer to DTC P0101  for further diagnosis.
  7. If all conditions test normal, test the engine for a mechanical condition. Refer to Symptoms - Engine Mechanical for further diagnosis.
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