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.
Fuel and Emissions System Description - EVAP Control System
2011 Acura TL FWD V6-3.5LSECTION Fuel and Emissions System Description - EVAP Control System
Fuel and Emissions System Description - EVAP Control System
Evaporative Emission (EVAP) Control System
Refer to the system diagram to see a functional layout of the system.
EVAP Canister
The EVAP canister temporarily stores fuel vapor from the fuel tank until it can be purged from the EVAP canister into the engine and burned.
EVAP Canister Purge Valve
When the engine coolant temperature is below 140 °F (60 °C), the ECM/PCM turns off the EVAP canister purge valve which cuts vacuum to the EVAP canister.
Fuel Tank Pressure (FTP) Sensor
The FTP sensor converts fuel tank absolute pressure into an electrical input to the ECM/PCM.
EVAP Canister Vent Shut Valve
The EVAP canister vent shut valve is on the EVAP canister.
The EVAP canister vent shut valve controls the venting of the EVAP canister.
Evaporative Emission (EVAP) Control Diagram
The EVAP controls minimize the amount of fuel vapor escaping to the atmosphere. Vapor from the fuel tank is temporarily stored in the EVAP canister until it can be purged from the canister into the engine and burned.
- The EVAP canister is purged by drawing fresh air through it and into a port on the intake manifold.
The purging vacuum is controlled by the EVAP canister purge valve, which operates whenever the engine coolant temperature is above 140 °F (60 °C).
- During refueling, the fuel tank vapor control valve opens from pressure in the fuel tank and feeds the fuel vapor to the EVAP canister.
Fuel Cap Warning Message
The ECM/PCM detects a loose or missing fuel fill cap as an evaporative system leak and alerts the driver by showing a warning message in the gauge display.
The first time a leak is detected a TIGHTEN FUEL CAP message appears on the gauge display (A). To scroll to another message, press the select/reset button. The "TIGHTEN FUEL CAP" message appears each time you restart the engine until the system turns the message off. Turn the engine off, then replace or tighten the fuel fill cap until it clicks at least once.
How to clear the message with the HDS
Procedure
- Tighten the fuel fill cap until it clicks.
- Clear the Pending DTC with the HDS.
- Verify there is no leak by doing the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
How to clear the message without the HDS
Procedure
- Tighten the fuel fill cap until it clicks.
- Start the engine, then turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Repeat step 2 two more times.
RENDER: 1.0x
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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.