MODEL IDENTIFICATION
Vehicle model is identified by fourth character of Vehicle Identification Number (VIN). VIN is stamped on metal pad on top of left end of instrument panel, near windshield. See MODEL IDENTIFICATION table.
| Body Code (1) | Model |
|---|---|
| N | Alero, Grand Am, Malibu |
| W | Century, Grand Prix, Impala & Monte Carlo |
| (1) Vehicle body code is fourth character of VIN. | |
| (1) | Vehicle body code is fourth character of VIN. |
MODEL IDENTIFICATION
Description
This procedure satisfies enable criteria necessary to execute all monitor diagnostics, and complete trips for those particular diagnostics. When all diagnostic tests have been completed, I/M SYSTEM STATUS indicators are set to YES. Perform this test when more than one or all I/M SYSTEM STATUS indicators are set to NO.
This test should satisfy enable criteria necessary to execute I/M readiness diagnostics for the catalyst system. Test may be used to set I/M SYSTEM STATUS indicators to YES.
This test should satisfy enable criteria necessary to execute I/M readiness diagnostics for the EGR system. Test may be used to set I/M SYSTEM STATUS indicators to YES.
Purpose of this test is to satisfy enable criteria necessary to execute I/M readiness diagnostics for Evaporative Emission (EVAP) system. Test may be used to set I/M SYSTEM STATUS indicators to YES. Service Bay Tests are included on scan tool for some systems depending upon vehicle make and model. Test is designed to allow EVAP diagnostic tests to run in service bay conditions. Ensure vehicle meets requirements listed in enable criteria before performing either EVAP system test. Failure to meet necessary requirements may produce inaccurate test results.
Purpose of this test is to satisfy enable criteria necessary to execute I/M readiness diagnostics for oxygen sensor (O2S, HO2S) system. Test may be used to set I/M SYSTEM STATUS to YES. Ensure vehicle meets requirements listed in enable criteria before performing this test. Failure to meet necessary requirements may produce inaccurate test results.
Purpose of this test is to satisfy enable criteria necessary to execute I/M readiness diagnostics for Heated Oxygen Sensor (HO2S) system. The test may be used to set I/M SYSTEM STATUS to YES. Ensure vehicle meets enable criteria before performing this test. Failure to meet necessary requirements may produce inaccurate test results.
Test Description
The numbers below refer to the step numbers on the diagnostic procedure.
- 4 - Tests for the proper operation of the circuit in the low voltage range.
- 5 - Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
- 6 - Tests for a short to voltage in the 5-volt reference circuit.
- 7 - Tests for a high resistance or an open in the low reference circuit.
- 16 - Perform programming procedure for PCM.