Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Hummer H2FACTORY OEM SERVICE PROCEDURE
Test Procedure
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
- If diagnostic system check for system exhibiting symptom has been performed, go to next step. If diagnostic system check for system exhibiting symptom has not been performed, perform appropriate diagnostic system check for suspect system. See BODY CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECKΒ under SELF-DIAGNOSTIC SYSTEM.
- Connect scan tool to Data Link Connector (DLC). DLC is located below driver side of instrument panel, near steering column. Turn ignition switch to RUN position. Using scan tool, retrieve DTCs. If DTC B1000 is retrieved as current, go to next step. If DTC B1000 is not retrieved as current, see DIAGNOSTIC AIDSΒ .
- Replace control module with DTC B1000 set. Program control module, if necessary. See PROGRAMMINGΒ . After repair, go to next step.
- Using scan tool, clear DTCs. Operate vehicle within code enable criteria. See CODE ENABLE CRITERIAΒ . If DTC resets, repeat test beginning at step Β 2.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.
