Acura RL Check Engine light?

A check engine light on your Acura RL only tells have the story, if it’s running rough or not starting, we may have your answer.  Working on an Acura RL, particularly 1995-2005 models, I’ve encountered my fair share of EVAP system issues. The first thing you’ll likely see is an engine light. I can’t imagine anything more frustrating than having this car and it running rough, or not starting at all.  Let’s look at how to troubleshoot and fix these issues, focusing on the EVAP control valves.

Engine light or long start?  Transmission issues?  Engine light and running rough?

Check for Recalls

Understanding the EVAP System in Your Acura RL

The Evaporative Emission Control System, captures gas vapors from the fuel tank and stores them in a charcoal canister safely burning them in the engine. This is required for the environment and improves your vehicle’s efficiency.

Role of EVAP Control Valves

The control valves manage the flow of vapors into the engine. If these valves fail, you’ll see a noticeable drop in fuel efficiency, increased emissions, and that dreaded engine light.

Acura RL Troubleshooting

• Check Engine.  The first sign is often the engine light. Use an OBD-II scanner to read the codes. Common codes include P0440, P0441, P0442, P0446, P0455, and P0456.  See all the OBD codes here.
• Gas Cap.  A loose or faulty gas cap can trigger EVAP system codes. Check if it’s tight and in good condition.
• Visible Signs of Damage.  Inspect the EVAP hoses and connections for cracks or loose fittings. Any damage here can cause leaks that affect the system’s performance.
• Locate the EVAP Control Valve: It’s typically found near the fuel tank or the charcoal canister.
• Test the EVAP Control Valves.  The control valves can be tested using a vacuum pump. If they don’t hold vacuum, they need to be replaced.
  • Visual Inspection:  Check for any signs of damage, cracks, or loose connections.
  • Disconnect the Valve:  Carefully disconnect the electrical connector and vacuum lines from the valve. Note how they were connected.
  • Test the Valve with a Multimeter:  Set your multimeter to the ohms (resistance) setting.  Connect the multimeter leads to the valve’s terminals.  A normal reading typically falls within a specific range, often between 20-30 ohms, but check your vehicle’s manual.
  • Perform a Vacuum Test:  Connect a hand-held vacuum pump to the valve’s port.  Apply vacuum to the valve and observe if it holds vacuum.
  • Check Valve Operation:  Reconnect the electrical connector to the valve.  Turn on the vehicle’s ignition (do not start the engine).  Use the multimeter in voltage mode to check if the valve is receiving voltage.  A functioning valve should receive voltage when the engine is idling (consult the vehicle manual for specifics).
  • Reconnect Everything:  Once testing is complete, reconnect all vacuum lines and electrical connections as they were originally.

Replacing Failed EVAP Control Valves

1. Disconnect the Battery: Always disconnect the battery before working on your car’s electrical components.
2. Remove the Old Valves: Unplug the electrical connector and hoses. Then, unscrew the valve from its mounting.
3. Install the New Valves: Place the new valves in the same position as the old ones and reattach everything.
4. Reconnect the Battery and Test Drive: After installation, reconnect your battery and take a short test drive to ensure the issue is resolved.

Final Thoughts

Your car is noticeably having issues… it may be running rough or just not starting. Dealing with EVAP system issues can be tough.  Hopefully this page make it manageable.  For RL owners, I made this page to bring awareness of the EVAP system’s role and knowing how to address common issues. Stay vigilant for that engine light and happy motoring!