'98 - 00 models:
The scan tool indicates Diagnostic Trouble code (DTC) P1456: Evaporative Emission (EVAP) control system leak
detected {fuel tank system).
Troubleshooting Flowchart
- The MIL has been reported on.- DTC P1456 is stored.
Check the fuel fill cap:Check the fuel fill cap (the caP
must be a gray OEM cap and be
tightened at least three "clicks" toproperly seal the system)-
ls the proper fuel fill cap installed
and properly tightened?Replace or tighton the cap.
Check the lueltill cap seal:
Check the fuel fill cap seal.
Replace the luelfiller pipe.ls the tuel filler pipe damaged?
Fuel till caD is OK. Do the luel
tank pressure Sensor test (see
page 11-2111. (EVAP Purge con-
trol solenoid valve t€sl (see Page11-2151.1r':'99 - 00 models
(cont'd)
11-213
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Emission Control System
Evaporative Emission IEVAPI Controls (cont'd)
lTi,t56l ("onto)
Vacuum hoses and connectionstelit.(The continuarion of DTC P1456troubleshooiing.l
Check the vacuum ho3es andconnect|ons:Check the following parts forleaks at atmospheric p ressu re{see page 11-204).. Fueltank. Fuel fill cap. Fuelfill pipe. EVAP two way valve. Fueltank pressure sensor
Repair or replaco the parts.
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away, replac€the original ECM/PCM.
11-218
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Canbter system leak test
{The continuation of DTC P1457
trouble3hootin9.)
Chock the EVAP control canistervent shut valve line and connoc'
tonS:1. Turn the ignition switch OFF
2. Connect to three'way tee fit_
tings into the hose from the
EVAP control canister to the
EVAP two way valve. Connect
the fuel tank pressure sensor
to one of the tee fittings and
the vacuum PumP to the other'
3. Remove the vent hose from
the EVAP control canister vent
shut valve and cap the Pon to
seal the fresh air vent Ior the
EVAP control canister.4. Turn the ignition switch ON (ll).
5. While monitoring the FTP
Sensor voltage with the Honda
PGM Tester, or measurangvoltage between ECM/PCM
connector terminals A29 and
C18 slowly PumP the vacuumpump using a stroke every 1 -
2 seconds.6. Continue to PumP vacuum
until that voltage droPs to
approx. 1.5 V.NOTE: Make sure that the
engine coolant temPeraturestillabove 95'F (35'Cland Yourvacuum PumP has no leak
7. Monitor that voltage for 20
seconds.
Check the EVAP Pu.ge control
solenoid valve line and connec-
tions:1. Turn the ignition switch OFF.
2. Disconnect the Purge lane
hose from the EVAP control
canister and Plug the Port3. Turn the ignition switch ON (lli.
4. While monitoring the FTP
Sensor voltage with the Honda
PGM Tester, or measuringvoltage between ECM/PCM
connector terminals A29 and
Cl8 slowly PumP the vacuumpump using a stroke every 1 -
2 seconds.5. Continue to pump vacuum
until that voltage droPs to
approx. 1-5 V.NOTE: Make sure that the
engine coolant temPeraturestill above 95'F (35"C) and Yourvacuum pump has no leak-
6. Monitor that voltage tor 20
seconds.
Doesthe voltage drop to 1.5 V
and holds at least 20 seconds?
lGp€ct the EVAP control cani3tel
vent 3hut valvo line and connec_
tion5.
Inlpect tho EVAP Putge control
solenoid valvo line and connec'
tion3. It th6y lro OK, do the EVAP
two way valve te3t (seo page 11-
2211.
Does the voltage drop to 1.5 V
and holds at least 20 seconds?
Reolace the EVAP conirol canister.
EVAPBYPASSSOLENOIDVALVE
FUEL TANK
EVAPCONTROL
VENTSHUTVALVE
EVAPCONTROLCANISTER
SENSOR
EVAP TWO WAYVALVE
EVAPTHREE
VALVE
ttrrL
ta
VACUUMPUMP/GAUGE,0 - 30 in.HgA973X -
041 -
XXXXX
FITTINGS
ECM/PCM CONNECTORS
A {32P)
PTANK ILT GRN)
c (31Pt
SG2 {GRN/BLK)
Wire side of female terminals
{cont'd)
11-223
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Emission Control System
Evaporative Emission (EVAP) Controls (cont,dl
Evaporative Emission (EVAP) Two Way Valve Testing
'97 model:
1. Remove the fuelfill cap.
2. Remove the vapor Iine from the EVAP two wayvalve on the fuel tank, and connect it to a T_fittingfrom a vacuum gauge and a vacuum pump asshown.
VACUUM,/PRESSURE GAUGEotJAz - 001 rDoBT-FITTINGVACUUMPUMP/GAUGE,0 - 30 in.HgA973X-041-XXXXX
3. Apply vacuum slowly and continuouslv whilewatching the gauge. The vacuum should stabilizemomentarily at 0.7 - 2.0 kpa (5 - 1S mmHg, 0.2 _ 0.6in.Hg).
lf the vacuum stabilizes (valve opens) below0.7 kPa (5 mmHg,0.2 in,Hg) or above 2.0 kpa(15 mmHg, 0.6 in.Hg), install a new valve and retest.
4.Move the vacuum pump hose from the vacuum fit_ting to the pressure fitting, and move the vacuumgauge hose from the vacuum side to the pressureside as shown.
PiESSURESIDE
5. Slowly pressurize the vapor line while watching thegauge. The pressure should stabilize at 1.3 - 4.7 kpa(0 - 35 mmHg, 0.4 - 1.4 in.Hg).. lf the pressure momentarily stabilizes (valve
opens) at 1.3 - 4.7 kpa (10 - 35 mmHg, 0.4 _ 1.4in. Hg), the valve is OK.. lf th6 pressure stabilizes below 1.3 kpa fio mmHg,0.4 inrHg) or above 4.7 kpa (35 mmHg, 1.4 in.Hg),install a new valve and retest.
T-FITTING
11-224
.98 - 0O models:
1. Remove the fuel fill cap.2. Remove the vapor line from the EVAP two wayvalve {located above the EVAP control canister). andconnect it to a T-fitting from vacuum gauge andvacuum pump as shown.
VACUUM/PRESSUFE
VACUUM PUMP/GAUGE,0 - 30 in.HgA973X - 041 -
xxxxx
5.
Apply vacuum slowly and continuously whilewatching the gauge.
The vacuum should stabilize momentarily at O.g _
2.1 kPa (6 - 16 mmHg, 0.2 - 0.6 in.Hg).lf the vacuum stabilizes (valve opens) below0.8 kPa (6 mmHg, 0.2 in.Hg) or above 2.1 kpa(16 mmHg, 0.6 in.Hg), install a new valve and retest.Move the vacuum pump hose from the vacuum fit-ting to the pressure fitting. and move the vacuumgauge hose from the vacuum side to the pressure
side as shown.
Slowly pressurize the vapor line while watching thegauge.
The pressure should stabilize momentarilv above1.0 kPa (8 mmHg, 0.3 in.Hg).a lf the pressure momentarily stabilizes (valve
opens) above 1.0 kPa (8 mmHg. 0.3 in.Hg), thevalve is OK.. lf the pressure stabilizes below ,|.0 kpa {g mmHg.0.3 in.Hg), install a new valve and retest.
T-FITTING
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