Fuel Fill Cap Check

Check the fuel fill cap (the cap must say "If not tightened 3 clicks check engine light may come on").
Is the correct fuel fill cap installed and properly tightened?
1. YES -Go to step 2.
2. NO -Replace or tighten the cap.
Check the fuel fill cap seal.
Is the fuel fill cap seal missing or damaged?
1. YES -Replace the fuel fill cap.
2. NO -The fuel fill cap is OK. Go to step 3.
EVAP Bypass Solenoid Valve Test
Remove the EVAP canister cover (see step 1 on EVAP Canister Replacement ).
Disconnect both vacuum hoses from the EVAP two way valve (A), and connect a vacuum pump to the canister port on the EVAP two way valve.

Fig 1: Connecting Vacuum Pump To The Canister Port On The EVAP Two Way Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the EVAP bypass solenoid valve on with the scan tool or the HDS, or connect PCM connector terminal A3 to body ground with a jumper wire.

Fig 2: Connecting PCM Connector Terminal A3 To Body Ground With A Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch ON (II).
Apply vacuum to the hose.
Does the valve hold vacuum?
1. YES -Go to step 8.
2. NO -Go to step 13.
Turn the ignition switch OFF.
Disconnect the EVAP bypass solenoid valve 2P connector.
Check for continuity between EVAP bypass solenoid valve 2P connector terminal No. 2 and body ground.

Fig 3: Checking For Continuity Between EVAP Bypass Solenoid Valve 2P Connector Terminal No. 2 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES -Go to step 11.
2. NO -Repair open in the wire between the EVAP bypass solenoid valve and the PCM (A3).
Turn the ignition switch ON (II).
Measure voltage between EVAP bypass solenoid valve 2P connector terminal No. 1 and body ground.

Fig 4: Measuring Voltage Between EVAP Bypass Solenoid Valve 2P Connector Terminal No. 1 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES -Replace the EVAP bypass solenoid valve (A) and the O-rings (B).
2. NO -Repair open in the wire between the EVAP bypass solenoid valve and the No. 6 ECU (PCM) CRUISE CONTROL (15A) fuse.
  
  Fig 5: Replacing The EVAP Bypass Solenoid Valve & The O-Rings
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
Plug the upper port (A) of the EVAP two way valve.

Fig 6: Plugging The Upper Port Of The EVAP Two Way Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.

NOTE: Do not apply too much vacuum or you will damage the FTP sensor.

Fig 7: Measuring The Voltage Between PCM Connector Terminals A29 & C18

Courtesy of AMERICAN HONDA MOTOR CO., INC.

While monitoring FTP sensor voltage with the scan tool or the HDS, or measuring the voltage between PCM connector terminals A29 and C18, slowly pump the vacuum pump until the voltage drops to about 1.5 volts.
Does the voltage drop to 1.5 V and hold for at least 20 seconds?
1. YES -The EVAP bypass solenoid valve/EVAP two way valve is OK. Go to step 15.
2. NO -Repair the leak from the EVAP bypass solenoid valve, EVAP two way valve, FTP sensor, or O-rings.
Vacuum Hoses and Connections Test
Perform the fuel tank vapor control valve test (see Fuel Tank Vapor Control Valve Test ).
Is the fuel tank vapor control valve OK?
1. YES -Go to step 16.
2. NO -Replace the fuel tank vapor control valve.
Tighten the fuel fill cap 3 "clicks", then monitor the FTP sensor readings with the scan tool or the HDS.
Start the engine, and let it idle for 5 minutes.
Check the FTP sensor readings.
Is the reading above 0.5 kPa (4 mmHg, 0.16 in.Hg) pressure, or about 3 V?
1. YES -Intermittent failure, system is OK at this time. Make sure the fuel cap is tightened 3 "clicks".
2. NO -Check the following parts for leaks:
  - Fuel tank (A)
  - Fuel fill cap (B)
  - Fuel fill pipe (C)
  - Fuel tank vapor control valve (D)
  - Fuel tank vapor recirculation valve (E)
  - Fuel tank vapor recirculation tube (F)
  - Fuel tank vapor signal tube (G)
  - EVAP two way valve (H)
  - FTP sensor (I)
    - If necessary, repair or replace the parts.