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.
2010 GMC Savana 3500 V8-6.0LFACTORY OEM SERVICE PROCEDURE
Fuel Composition Diagnosis
Fuel Composition Diagnosis
System Description
When an E85 compatible vehicle is built, an engine control module (ECM) or powertrain control module (PCM) replaced, or when the learned alcohol content has been reset with a scan tool, the fuel system will need to contain ASTM gasoline with 10 percent or less ethanol content. If the fuel in the fuel system needs to be drained and replaced with ASTM gasoline, the engine will need to run at operating temperature and consume at least 1 liter (0.3 gallon) of fuel before the system will recognize the correct alcohol content. Either ASTM gasoline or ASTM E85 fuel can then be used.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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