Honda Civic Service Manual page 387

EVAP System
DTC Troubleshooting (cont'd)
DTC Pl457: EVAP Control System
(EVAP Canister System)
Leakage
The fuel system is designed to allow specified
maximum vacuum and pressure conditions. Do not
deviate from the vacuum and pressure tests as
indicated in these procedures. Excessive pressure/
vacuum would damage the EVAP components or
cause eventual fuel tank system failure.
SpecialTools Required
Vacuum pump/gauge, 0-30 in.Hg A973X-041-XXXXX
This is a two-trip code. Once cleared, it cannot be
reproduced in one trip. Also, certain specific driving
and ambient conditions must occur before the ECfM will
complete the system checks, Additional test drives may
still not meet the specific conditions needed to
1 6 ^ r ^ . 1 ' ' ^ 6 r h 6 ^ ^ . 1 6
Follow these troubleshooting procedures carefully to
ensure the integrity of the system and to confirm the
cause of the problem or code.
NOTE: Fresh fuel has a higher volatility lhat creates
greater pressure/vacuum. The optimum condition for
testing is fresh fuel, and there must be less than a full
tank. lf possible, to assist in leak detection, add I gallon
of fresh fuel to the tank (as long as it will not fill the
tank), just before starting these procedures.
EVAP Canister Purge Valve Test
1. Disconnect the vacuum hose from the EVAP
canister purge valve (A), and connect a vacuum
pump to the hose.
1 1 - 1 8 0
4973X-041-XXXXX
ECM CONNECTOR A I24P'
W i r e s i d e o f l e m a l e t e r m i n a l s
4 .
7 .
2. Turn the EVAP canister purge valve on with the
Honda PGM Tester, or connect ECM connector
terminal 821 to body ground with a jumper wire.
Turn the ignition switch ON (ll).
Apply vacuum to the hose.
Does the valve hold vacuum?
YES-Go to step 5.
NO-The EVAP canister purge valve is OK. Go to
step 10.
Turn the ignition switch OFF.
Disconnect the EVAP canister purge valve 2P
conneclor,
Check for continuity between EVAP canister purge
valve 2P connector terminal No. 2 and body ground.
EVAPCANISTEN PURG€
VALVE 2P CONNECTOR
-4-
l l l 2 l
-fircs
IYEL/8Lu)
(f])
I
W i r e s i d e o f f e m a l e l e r m i n a l s
ls there continuity?
YES-Go to step 8.
NO Repair open in the wire between the EVAP
c a n i s t e r p u r g e v a l v e a n d t h e E C M / P C M ( 8 2 1 ) . I
T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
t
b .
8 .