LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1446 (Engine Control System - 4.2L - Troubleshooting & Diagnosis) >> Diagnosis Information & Procedures >> Inspection/Maintenance (I/M) System Check >> Diagnostic Aids

Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The I/M System Status display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, the failure indication may prevent other required tests from running. For example, a DTC for the control circuit of the relay controlling an AIR pump may not be listed in the Inspection/Maintenance System DTC Table because this is a continuous test. If this DTC is set, the Active Tests for the AIR system may not run.

The I/M System Status information may be useful for a technician to determine if diagnostics have run when verifying repairs.

Inspection/Maintenance (I/M) System Check

Step Action Yes No
1
  1. Perform the Diagnostic System Check - Engine Controls .
    2. IMPORTANT: Many DTC related repairs will instruct the technician to clear the DTC information. This procedure will reset ALL of the I/M System Status indicators to NO, and require performing the I/M Complete System Set Procedure.
  2. Repair any DTCs or driveability concerns that would prevent the I/M System Status tests from completing.
Did you find and repair a DTC or driveability concern?		 Go to Step 3  Go to Step 2 
2
  1. Review any service bulletins for software updates that may prevent I/M readiness.
  2. Perform any reprogramming or repairs indicated by the service bulletins.
Was a reprogramming or repair service required?		 Go to Inspection/Maintenance (I/M) Complete System Set Procedure  Go to Step 3 
3 Observe the I/M System Status display, with a scan tool.
Is more than one test indicating a NO status?		 Go to Inspection/Maintenance (I/M) Complete System Set Procedure  Go to the I/M System Set Procedure for the indicated system that has not updated to YES
scientia non olet · About LEMON Manuals