Diagnostic Procedures

2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8SECTION Diagnostic Procedures
WARNING: This page is about a different variant/trim than selected.
  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. Review any service bulletins for software updates that may prevent I/M readiness. Perform any reprogramming or repairs indicated by the service bulletins. If reprogramming or repair service was required, go to INSPECTION/MAINTENANCE COMPLETE SYSTEM SET PROCEDURE . If reprogramming or repair service was not required, go next step.
  3. Using scan tool, observe the I/M SYSTEM STATUS display. If more than one test is indicating a NO status, go to INSPECTION/MAINTENANCE COMPLETE SYSTEM SET PROCEDURE . If only one test is indicating a NO status, perform appropriate I/M system set procedure for the indicated system. See INSPECTION/MAINTENANCE SYSTEM SET PROCEDURE INDEX  table.
INSPECTION/MAINTENANCE SYSTEM SET PROCEDURE INDEX

System With NO Status Perform
AIR System INSPECTION/MAINTENANCE AIR SYSTEM SET PROCEDURE 
Catalyst System INSPECTION/MAINTENANCE CATALYST SYSTEM SET PROCEDURE 
EGR System INSPECTION/MAINTENANCE EXHAUST GAS RECIRCULATION SYSTEM SET PROCEDURE 
EVAP System INSPECTION/MAINTENANCE EVAPORATIVE EMISSION SYSTEM SET PROCEDURE 
HO2S/O2S System INSPECTION/MAINTENANCE HEATED OXYGEN SENSOR SYSTEM SET PROCEDURE 
HO2S Heater System INSPECTION/MAINTENANCE HEATED OXYGEN SENSOR HEATER SYSTEM SET PROCEDURE 
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.