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Home >> Chevrolet >> 2021 >> Blazer RS, FWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 9 (Engine Controls And Fuel - 2.5L (LCV) - Diagnostic Information And Procedures (1 Of 2)) >> Diagnostic Information and Procedures >> DTC P0121-P0123, P0222, P0223, P2135, U0606, or U0607 >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different variant/trim than selected.
NOTE:

If you were sent here from DTC P0068, P0101, P010B, P0106, P0236, P1101 - Refer to: Circuit/System Testing.

  1. Ignition - On / Vehicle - In Service Mode
  2. Verify DTC P0601-P0606, P06A3, P16F3 is not set.
    • Go to next step: If none of the DTCs are set 
  3. Verify the scan tool parameter: Throttle Body Idle Air Flow Compensation = Less than 90%
    • Go to next step: If less than 90% 
  4. Verify DTC P0122, P0123, P0222, P0223, P2135 is not set.
    • If only DTC P0122, P0123, P0222, P0223, P2135 is set 

      Test or replace the component: Q38 Throttle Body

    • If DTC U0606, U0607 and one or more of the DTCs P0122, P0123, P0222, P0223, P2135 is set 

      Refer to: Circuit/System Testing

    • Go to next step: If none of the DTCs are set 
  5. Perform the scan tool control function: Throttle Sweep - Start

    Verify the scan tool parameter: Throttle Position Sensors 1 and 2 = Agree

    • If not the specified state 

      Test or replace the component: Q38 Throttle Body

    • Go to next step: If the specified state 
  6. Verify the scan tool parameter: Manifold Absolute Pressure Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure
    • If not in the specified range 
  7. Refer to: DTC P0106, P0107, or P0108 
    • Go to next step: If in the specified range 
  8. Engine - Running
  9. Verify the scan tool parameter:
    • Manifold Absolute Pressure Sensor = 26 to 52 kPa (3.8 to 7.5 PSI) @ Idle Speed
    • Manifold Absolute Pressure Sensor = The value should change with accelerator pedal input.
    • Go to next step: If in the specified range and changes 
  10. Increase the engine speed slowly to 3k RPM and then back to idle.
  11. Perform the scan tool function: Review Stored Data
  12. Observe the scan tool parameter frame by frame with a scan tool: MAF Sensor

    Verify the scan tool parameter: MAF Sensor = The value should not spike or drop out.

    • Go to next step: If the value does not spike or drop out 
  13. 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.

    Verify the DTC does not set.

    • If the DTC sets 

      Refer to: Circuit/System Testing

    • Go to next step: If the DTC does not set 
  14. All OK.