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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Envoy - 2WD 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Inspection/Maintenance (I/M) Complete System Set Procedure

Diagnostic Instructions
    •  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The purpose of the Inspection/Maintenance (I/M) complete system set procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the trips for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the I/M Complete System Set Procedure if any I/M System Status indicators are set to NO.

I/M Data List

To determine if the I/M readiness diagnostic tests can be run this ignition cycle, use a scan tool to observe the I/M monitor enabled parameters in the I/M Data List.

Conditions for Meeting a Cold Start
    • The ignition voltage between 11-18 volts.
    • The barometric pressure (BARO) is more than 75 kPa.
    • The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
    • The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
    • The difference between the IAT and the ECT is less than 6°C (10.8°F)
    • The ambient air temperature is between 4-30°C (39-86°F).
    • The fuel level is between 15-85 percent.
    • Vehicle has NOT been refueled since the last cold start ignition cycle.

Circuit/System Verification

Review the I/M System Status indicators. All I/M System Status indicators should report YES.

Inspection/Maintenance (I/M) System Set Procedure

    Important: Whenever the ignition is turned ON, ignition positive voltage is supplied to the heated oxygen sensor (HO2S) heaters. After verifying the enable criteria, turn OFF the ignition for approximately 5 minutes to allow the sensors to cool before continuing with the test. Once the engine is started, do NOT turn the engine OFF for the remaining portion of the set procedure.

  1. Ensure that the vehicle meets the conditions for a cold start listed above.
    2. ⇒If the evaporative emission (EVAP) I/M System Status indicator displays NO, perform the EVAP Service bay test if applicable.
    ⇒If the EVAP Service Bay Test is NOT available, it may take up to 6 drive cycles, with up to 17 hours between drive cycles, for the EVAP I/M System Status indicator to transition to YES.
    ⇒If the O2S Heater System Status indicator displays NO, ensure that the ignition has been turned OFF for at least 10 hours.
  2. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc.
  3. Set the vehicle parking brake and ensure the vehicle is in park for automatic transmission or neutral for manual transmission.
  4. Turn the ignition ON with the engine OFF for 1 minute.
  5. Start and idle the engine for 2 minutes and until 65°C (149°F) is achieved.
  6. Run the engine for 8 minutes within the following conditions:
    7. • MAF parameter between 4-30 g/s
    • Engine speed steady between 1,000-3,000 RPM
  7. Apply and hold brake pedal, and shift to Drive for automatic, or apply clutch pedal for manual and operate the vehicle within the following conditions for 2 minutes:
    8. • Mass air flow (MAF) signal between 4-30 g/s
    • RPM steady between 1,200-1,500 RPM

    Important: Do NOT touch the accelerator pedal during the idle period. A change in throttle position (TP) Sensor angle or an increase in engine speed may invalidate this portion of the test.

  8. Release the accelerator pedal and allow the engine to idle for 2 minutes.

    9. Caution: Refer to Road Test Caution in the Preface section.

  9. Release the parking brake and drive vehicle for at least 5.5 miles between 45-112 km/h (28-70 mph) with the vehicle reaching at least 80 km/h (50 mph).
  10. Safely stop the vehicle. With the brake pedal applied, allow the engine to idle for 2 minutes.
  11. Apply the parking brake and shift to Park for automatic, or Neutral and release clutch pedal for manual.

    12. Important: Do NOT disturb the vehicle or turn ON the ignition until told to do so. Disturbing the vehicle may invalidate this portion of the test.

  12. Turn OFF the ignition and exit the vehicle. Do NOT disturb the vehicle for 45 minutes.
  13. Observe the I/M System Status with a scan tool. All of the I/M System Status indicators should display YES.
    14. ⇒If the EVAP I/M System Status indicator displays NO turn OFF the ignition for 17 hours, ensure that the vehicle meets the conditions for a cold start, and repeat steps 9-13 six more times, or until the EVAP I/M System Status indicator transitions to YES. If the indicator continues to display NO, refer to the Inspection/Maintenance (I/M) System DTC Table to identify the DTCs that did not run.
    ⇒If any of the I/M System Status indicators display NO, refer to the Inspection/Maintenance (I/M) System DTC Table for the indicator which did not display YES. The I/M System DTC Table identifies the DTCs associated with each I/M System Status Indicator.