Honda Civic. Manual — part 615

1. Check the fuel fill cap (the cap must say "TIGHTEN TO CLICK"). It should

turn 1/4 turn 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 22.

2. 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. 18: Checking Fuel Fill Cap Seal And Mating Surface
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is the fuel fill cap seal missing or damaged, is the fuel fill pipe damaged, or is

NOTE:

Before you troubleshoot, record all freeze data and any
on-board snapshot, and review the general
troubleshooting information (see GENERAL
TROUBLESHOOTING INFORMATION ).

Fresh fuel has a higher volatility that will create greater
pressure/vacuum. The optimum condition for testing is
less than a full tank of fresh fuel. If possible, to assist in
leak detection, add 1 gallon of fresh fuel to the tank (as
long as it will not fill the tank), just before starting these
procedures.

2008 Honda Civic EX

2006-08 ENGINE PERFORMANCE EVAP System (R18A1) - Civic (All Except Hybrid)

the tether cord caught under the cap?

YES - Replace the fuel fill cap or the fuel fill pipe, then go to step 22.

NO - Go to step 3.

3. Turn the ignition switch ON (II).
4. Clear the DTC with the HDS.
5. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

Is the result OK?

YES - Intermittent failure, the system is OK at this time. Check for poor
connections or loose terminals at the FTP sensor, the EVAP canister purge
valve, or the EVAP canister vent shut valve and the ECM/PCM.

NO - Go to step 6.

6. Turn the ignition switch OFF.
7. Check for a poor connection or damage at the fuel tank vapor recirculation

tube.

Is the tube OK?

YES - Go to step 8.

NO -

Replace the fuel tank vapor recirculation tube, then go to step 22.

If necessary, replace the fuel tank (see FUEL TANK
REPLACEMENT ), then go to step 22.

8. Disconnect the fuel tank vapor recirculation tube (A) from the EVAP canister

(B), and plug the EVAP canister port (C).

2008 Honda Civic EX

2006-08 ENGINE PERFORMANCE EVAP System (R18A1) - Civic (All Except Hybrid)

Fig. 19: Disconnecting Fuel Tank Vapor Recirculation Tube From EVAP
Canister
Courtesy of AMERICAN HONDA MOTOR CO., INC.

9. Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge

valve (B) in the engine compartment, and connect a vacuum pump/gauge, 0-30
in.Hg, to the vacuum hose as shown.

Fig. 20: Disconnecting Vacuum Hose (Purge Line) And EVAP Canister
Purge Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.

10. Turn the ignition switch ON (II).

2008 Honda Civic EX

2006-08 ENGINE PERFORMANCE EVAP System (R18A1) - Civic (All Except Hybrid)

11. Select EVAP CVS ON in the INSPECTION MENU with the HDS.
12. Apply vacuum to the hose until the FTP reads 1.90 V (-0.59 in.Hg,-15.1

mmHg).

13. Monitor the FTP SENSOR in the DATA LIST for 1 minute with the HDS.

Does the voltage increase more than 0.2 V (0.1 in.Hg, 0.5 mmHg)?

YES - Go to step 14.

NO - Go to step 19.

14. Select EVAP CVS OFF in the INSPECTION MENU with the HDS.
15. Disconnect the fresh air hose (A) from the EVAP canister (B), and plug the

EVAP canister port (C).

Fig. 21: Disconnecting Fresh Air Hose From EVAP Canister
Courtesy of AMERICAN HONDA MOTOR CO., INC.

16. Apply vacuum to the EVAP system until the FTP reads 1.90 V (-0.59 in.Hg,-

NOTE:

Be careful not to exceed the pressure. If you exceed the
pressure, the FTP sensor can be damaged.

2008 Honda Civic EX

2006-08 ENGINE PERFORMANCE EVAP System (R18A1) - Civic (All Except Hybrid)