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.
Test Description
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Test Description
WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedures.
- 2
This step tests the MAP sensors ability to correctly indicate barometric pressure.In order to determine the correct MAP sensor display of barometric pressure for any elevation perform either of the following:
- Compare the recorded MAP sensor display value to the BARO display on a known-good vehicle.
- Obtain the local weather service barometer reading (in. Hg). Multiply the barometer reading by 3.4. The result indicates the correct BARO value for your area.
- 3
This step tests the MAP sensors ability to correctly indicate engine vacuum. - 7
This step indicates this sensor is currently functioning correctly. If you were sent to this diagnostic procedure from other service information return to that procedure now.
RENDER: 1.0x
NO RELATED
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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.