Circuit Description
The purpose of the 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 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 74 kPa. |
| • | The engine coolant temperature (ECT) is below 35°C (95°F). |
| • | The intake air temperature (IAT) is below 35°C (95°F). |
| • | The difference between the IAT and the ECT is 6°C (11°F) or less. |
| • | The battery voltage is between 9-18 volts. |
| • | The fuel level is between ¼ and ¾. |
Diagnostic Aids
Rough road conditions may prevent some of the tests from running. Extreme high or low ambient temperatures may prevent tests such as heated oxygen sensor (HO2S) and 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.
If the vehicle has recently run, start this procedure at Step 3. This will allow the tests that require the engine at operating temperature to run. Using this method allows shorter cool down periods if the tests requiring a cold start do not initiate.
The scan tool can be used 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, it is not necessary 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.
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Make sure you perform the I/M System Check before performing this test. Failure to do so may result in difficulty updating the status to YES.
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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 HO2S heaters operate while verifying the enable criteria.
The engine control module considers the engine to be cold if the following conditions are met:
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This step is to run the EVAP, secondary air injection (AIR) and the HO2S 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 HO2S tests begin once the engine is at operating temperature, in Closed Loop fuel control, and a calibrated amount of time has elapsed.
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This step is to run the EGR tests. The exhaust gas recirculation (EGR) tests are run during a gradual deceleration with a closed throttle. The vehicle speed is required in order to maintain a high, steady manifold absolute pressure (MAP) signal.
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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.
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Perform the individual system test for any of the systems that do not update to YES.
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The I/M System Status only reports on whether or not a diagnostic has run, not the outcome of the test. If any emission related DTC sets after the tests are complete, the DTC will require diagnosis.
| • | Engine coolant temperature (ECT) less than 35°C (95°F) |
| • | ECT and IAT are within 6°C (11°F) of each other at start up |
Step | Action | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Did you perform the Inspection/Maintenance (I/M) System Check? | -- | Go to Step 2 | ||||||||||||||
Important: Whenever the ignition is turned ON, ignition positive voltage is supplied to the 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. Is the action complete? | 2 minutes | Go to Step 3 | -- | |||||||||||||
In order for the next group of tests to run, the vehicle must operate in the following conditions:
Is the action complete? | -- | Go to Step 4 | -- | |||||||||||||
In order for the next group of tests to run, the vehicle must operate in the following conditions:
Is the action complete? | -- | Go to Step 5 | -- | |||||||||||||
In order for the next group of tests to run, the vehicle must operate in the following conditions:
Is the action complete? | -- | Go to Step 6 | -- | |||||||||||||
Use the scan tool in order to observe the I/M System Status display. Did all of the I/M System Status indicators update to YES? | -- | Go to Step 7 | Go to the I/M System Set Procedure for the indicated systems | |||||||||||||
Use the scan tool in order to observe the Emission Related DTC portion of the I/M System Status display. Does the scan tool indicate any Emission Related DTCs set? | -- | System OK |
