GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 TrailBlazer - 2WD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Inspection/Maintenance (I/M) Complete System Set Procedure

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 to complete the trips for those particular diagnostics. When all diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform this test when more than one or all of the I/M System Status indicators are set to NO.

Conditions for Running

Cold Start

    • The barometric pressure (BARO) is more than 75 kPa.
    • The engine coolant temperature (ECT) is between 4-30°C (39-86°F).
    • The intake air temperature (IAT) is between 4-30°C (39-86°F).
    • The difference between the IAT and the ECT is 8°C (14°F) or less.
    • The battery voltage is between 10-18 volts.
    • The fuel level is between 15-85 percent.

Diagnostic Aids

Rough road conditions may prevent some of the tests from running. Extreme high or low ambient temperatures may prevent tests such as for the heated oxygen sensor (HO2S) heater and the evaporative emission (EVAP) system from initiating. If a step is interrupted before completion, perform the remaining portion of the set procedures. Any portion of the set procedure that requires the engine at operating temperature may be repeated. This allows most of the diagnostics to run and the remaining tests can be performed using the individual System Set Procedures.

The scan tool can be used in order to monitor each of the I/M System Status indicators during the I/M Complete System Set Procedure. When all of the indicators for a test step have updated to YES, testing can move on to the next step even if the remaining portion of the test is not complete. For example, step 3 is designed to run the EVAP, secondary air injection (AIR), and HO2S tests. The procedure instructs the technician to operate the vehicle in the enable conditions for 6 minutes. If all 3 tests have updated to YES within 4 minutes, you do not need to continue with the enable conditions and testing can advance to the next step.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step is to run the HO2S heater tests and initiate the EVAP System Test.

    Preprogramming the scan tool will reduce the amount of time the oxygen sensor heaters operate while verifying the enable criteria.

    2.

  2. This step is to run the EVAP, the AIR and the oxygen sensor tests. The EVAP test begins once the engine coolant reaches a calibrated temperature. The AIR test, if equipped, begins shortly after Closed Loop and the indicated speed is achieved. The oxygen sensor tests begin once the engine is at operating temperature, in Closed Loop Fuel Control, and a calibrated amount of time has elapsed.

    3.

  3. This step is to run the Catalyst Tests. This test runs during the idle period immediately following a cruise period that meets a minimum calibrated RPM and time period.

Step

Action

Value(s)

Yes

No

Caution: Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.

 

1

Did you perform the Inspection/Maintenance (I/M) System Check?

--

Go to Step 2

Go to Inspection/Maintenance (I/M) System Check

2

    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 in order 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. Preprogram the scan tool with the vehicle information before the ignition is turned ON.
  2. Ensure that the vehicle is within the Conditions for Running specified in the supporting text.
  3. Turn OFF all of the accessories, including the air conditioning (A/C), and blower fan.
  4. Set the vehicle parking brake.
  5. Verify the transmission is in Park for automatic transmissions (A/T) and Neutral for manual transmissions (M/T).
  6. Start the engine and allow it to idle for the specified time.

Is the action complete?

2 minutes

Go to Step 3

--

3

In order for the next group of tests to run, the vehicle must operate in the following conditions:

  1. Acceleration at part throttle to 90 km/h (55 mph), with this speed maintained until the engine reaches operating temperature. This may be up to 10 minutes depending on the start up coolant temperature.
  2. Continue operation under these conditions for an additional 6 minutes.

Is the action complete?

--

Go to Step 4

--

4

In order for the next group of tests to run, the vehicle must operate in the following conditions:

  1. Acceleration at part throttle to 75-89 km/h (45-55 mph) with this speed maintained for 2 minutes
  2. Brake safely to a stop.
  3. Engine idling for 2 minutes while the following criteria are maintained:
    4. • Service brake depressed
    • A/T in Drive
    • M/T in Neutral with the clutch pedal depressed

Is the action complete?

--

Go to Step 5

--

5

Observe the I/M System Status display with a scan tool.

Did all of the I/M System Status indicators update to YES?

--

Go to Step 6

Go to the I/M System Set Procedure for the systems that have not updated

6

Observe the emission related DTC portion of the I/M System Status display with a scan tool.

Does the scan tool indicate any emission related DTCs set?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK