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 Cap Warning Message System Troubleshooting
Special Tools Required
- Vacuum/Pressure Gauge, 0-4 In.Hg, 07JAZ-001000B
- Vacuum Pump/Gauge, 0-30 In.Hg, Snap-on YA4000A or equivalent, commercially available
Do this procedure if the fuel cap warning message comes on frequently, or if the message does not go off after the fuel fill cap is tightened and the vehicle is driven several days.
- Check the fuel fill cap (the cap must say TIGHTEN TO CLICK). It should turn 1/4 after it's tight, then it clicks.
Is the correct fuel fill cap Installed and properly tightened?
YES -Go to step 2.
NO -Replace or tighten the cap, then go to step 14.
- Check the fuel fill cap seal (A) and the fuel fill pipe mating surface (B). Verify that the fuel fill cap tether cord (C) is not caught under the cap.Fig 1: Identifying Fuel Fill Cap Seal And Fuel Fill Pipe Mating Surface With Fuel Fill Cap Tether Cord
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is the fuel fill cap seal missing or damaged, is the fuel fill pipe damaged, or is the tether cord caught under the cap?
YES -Replace the fuel fill cap or the fuel fill pipe, then go to step 13.
NO -Go to step 3.
- Reinstall and tighten the fuel fill cap.
- Clear the DTC with the HDS.
- Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
- Test-drive at 45 mph (72 km/h) for 1 minute or more.
Does the fuel fill cap warning message come on?
YES -Go to step 7.
NO -Intermittent failure, the system is OK at this time.
- Turn the ignition switch to LOCK (0).
- Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) in the engine compartment, then connect a T-fitting (C) from the vacuum gauge and the vacuum pump/gauge 0-30 In.Hg, to the EVAP canister purge valve as shown.
- Turn the ignition switch to ON (II).
- Apply about 2 kPa (0.6 In.Hg, 15 mmHg) of vacuum to the hose.
- Select EVAP PCS ON in the INSPECTION MENU with the HDS.
Does the vacuum release immediately?
YES -Check for a blockage at the EVAP canister purge line between the EVAP canister purge valve and the EVAP canister, then go to step 12.
NO -Replace the EVAP canister purge valve (see EVAP CANISTER PURGE VALVE REPLACEMENT ), then go to step 12.
- Reconnect all hoses.
- Turn the ignition switch to ON (II).
- Reset the PCM with the HDS.
- Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
- Test-drive at 45 mph (72 km/h) for 1 minute or more.
Does the fuel cap warning message come on?
YES -Go to step 1, and recheck.
NO -Troubleshooting is complete.
NO RELATED
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.