Page 409 of 1395
Chack iho EVAP purge controlsolenoid valve:1. Disconnect the vacuum hosetrom the EVAP controlcanister.2, Connect the vacuum pump tothe hose and apply vacuum,
Does it hold vacuum?
Chgck thg EVAP control csnbter:1. Reconnect the vacuum hose tothe EVAP control canister.2. Connect a vac!um gauge tothe purge air hose.3. Connect PCM connector terminals A15 and 410 with ajumper wire.4. Stan the engine.5. Check the vacuum.
Check the EVAP two way valve(see page 11'224).
Does the EVAP two way valvework properly?Rapbce the EVAP two wey valve.
Substitute a known-good PCMand rechock. It symptom/indica-tion gocs away, roplacg tho origi-nrl rcM.
(From page 11-206)
JUMPEF WIRE
<\
EVAP CONTNOLCANISTER
VACUUMPUMPIGAUGE,0-30 in.Hg4973X -
0il1 -
xxxxx
VACUUM/PRESSUREGAUGE0-4 in.Hg07JA2 - ml(x)o8
wire side of female terminals
{cont'd)
-20711
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Page 410 of 1395
Emission Control System
Evaporative Emission (EVAP) Controls (cont'd)
99 - 00 models:
The scan tool indicates Diagnostic Trouble Code {DTC) P0451: The Fuel Tank Pressure sensor circuit range/oerformance Droblem.
ECM/PCM CONNECTORS
SG2 {GRN/BLK)
Wire side of {emaleterminals
FUEL TANKPRESSURESENSOR
VACUUMPUMP/GAUGE.0 -30 in.H9A973X - 041 -
XXXXX
- The MIL har been rooort€d on.- DTC P0451 b storod.
Check lor th6 tu6l tank pr€ssurelen30r:1. Do the ECM/PCM Reset Proce,oure.2. Remove the fuelfill cap.3. Turn the ignition switch ON (ll).4. Monitor the FTP Sensor voltage with the Honda PGMTester, or measure voltagebetween ECM/PCM connectorterminals A29 and C18.
Chock tho vacuum lin6s torrGlriction o. blockago repair asnecessary. lf OK, roplace the fueltank Drer3ur€ sentor.
ls there approx. 2.5 V?
Check for the fuel tank piessureSensot:L Disconnect the hose betweenthe EVAP two way valve andthe fuel tank pressure sensor atthe EVAP two way valve end.2. Connect a vacuum pump tothe open end ofthat hose.3. Turn the ignition switch ON (lll.4. Monitor the FTP S€nsor volt-age with the Honda PGMTester, or measure voltagebetween ECNI/PCNI connectorterminals A29 and C18, andcarefully appiy vacuum on thehose one stroke at a time.5. The voltage should smoothlydrop from the staning approx.2.5 V down to approx. 1.5 V.STOP applying vacuum whenthe voltage drops to approx.1.5 V or damage to the tueltank pressure sensor may
Does the voltage drop to approx.1.5 V and hold?
Intermittent tailuro. sv3tem is OKat this tim€. Chack to. poor con-n€ction6 or 10036 hose at fu6ltank pres3ure ionsor and fueltrnk.
a t32Pl
PTANK ILT GRNI
WAY VALVE
11-208
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Page 412 of 1395
Emission Control System
Evaporative Emission (EVAP) Controls (cont'dl
FUEL TANKPRESSUNE SENSOR3P CONNECTOR tc646l
Wire side of female terminals
(From page l1'209)
Check lor a short in the wireIPTANK Iine}:Measure voltage betlveen the fueltank pressure sensor 3P connectorNo. 3terminal and No. 2terminal.
ls there approx.5 V?
Check for a short in the wire(PTANK line):1. Turn the ignition switch OFF.2. Disco n nect the ECM/PCMconnector A {32P).3. Check for continuity betweenthe fuel tank pressure sensor3P connector No. 3 terminalsand body ground.
Repair short in the wira betwgonthe fuel trnk prossure s6nsor andtho ECM/PCM lA29).
Sub.tituto a known-good ECM/PCM and r€check. lf 3ymptom/indication goer !way. replaceth6 original ECM/PCM.
11-210
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Page 414 of 1395
Emission Control System
Check fo. an open in the wire(PTANK linel:Measure voltage between ECM/PCM connector terminals A29 andc18.
Ropair open in the wire betweonthe ECM/PCM {A291 and tho fuoltank pressule 3ensor.
ls there approx.5 V?
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away, r€placetho originrl ECM/PCM.
Evaporative Emission (EVAP) Controls (cont'dl
(From page 11,211)
ECM/PCM CONNECTORS
SG2 (GRN/BLK}
Wire side of temale terminals
11-212
-
PTANK {LT GRNI
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Page 415 of 1395
'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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Page 416 of 1395
Emission Control System
Fuel tank pros3ure sensor tost.(The continuetion of DTC Pl456t.oubls3hooting.,
Chock the tusl trnk pr€3sure sen-sor:1. Remove the fuel fill csp.2. Turn the ignition switch ON fll).3. Monitor the FTP Sensor voh-age with th€ Honda PGMTester, or measure voltagebetween ECM/PCM conn€ctorterminals A29 and C18.
Choct ths vacuum linsr forra3triction o. blockago ropair a!nect*rary. It OK, replaca the fu6ltank praituJc sentot.
ls there approx. 2.5 V?
Check the fuel t nk pressuae 3en-sor:1. Turn the ignition switch OFF.2. Disconnect the hose betweenthe EVAP two way valve andthe tueltank pressure sensor atthe EVAP two way valve end.3. Connect a vacuum pump tothe open end ofthat hose.4. Turn the ignition switch ON 0l).5. Monitor the FTP Sensor volt-age with the Honda PGMTestet, or measure voltagebetween ECM/PCM connectorterminals 429 and C18, andcarefully apply vacuum on thehose one stroke at a lime.6. The voltage should smoothtydrop from the staning approx.2.5 V down to approx. 1.5 V.Stop applying vacuum whenthe voltage drops to approx.1.5 V or damage to the fueltank pressure sensor fiayoccur,
Fu.l tank pressu.c a€nlor b OK.Oo thc EVAP pulge controlsolenoid valve toat (3€€ prgo 11-2151.
Does the voltage drop to approx.1.5 V and hold?
Evaporative Emission (EVAPI Controls (contd)
lP14s6l("ont,a)
ECM/PCM CONNECTORS
SG2 IGRN/BLKI
Wire side oI female terminals
FUEI- TANKPRESSURESENSOR
VACUUMPUMP/GAUGE,0 - 30 in.HgA973X - ill -
xxxxx
EVAP TWOWAY VALVE
11-214
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Page 417 of 1395
EVAP purge control 3ol€noidvalve test.{Tho continu.tion of DTC Plil56
trouble3hootin9.)
Check the EVAP purge control
solenoid valve:1. Disconnect the vacuum hosetrom the EVAP control canis-
ter, and connect a vacuumpump to the hose.2. Turn the ignition switch ON (ll).
3. Apply vacuum to the hose.
EVAP purge contlol solenoidv.lvo is OK. Do the EVAP bypai3
solenoid valve test (see Page 11-
2161
Does the valve hold vacuum?
Check tho EVAP purge control
solenoid valve:'t. Turn the ignition switch OFF.2. Disconnect the EVAP Purgecontrol solenoid valve 2P con-nector,3. Check for continuity between
the EVAP pu rge controlsolenoid valve 2P connectorterminal No.2 and bodYground,
Check for s short in the wire
{PCS linel:1. D iscon nect the ECM/PCMconnector A {32P).2. Check for continuity betweenthe EVAP purge controlsolenoid valve 2P connectorterminal No. 2 and bodyground.
neprir short in tho wite bot$reon
the ECM/FCM lAGl and thc EVAPpurge control 3olenoid valve.ls there continuity?
Substitut€ a known-good ECM/
PCM and recheck. lf symptom/indication goe3 away. repl.ce
thc originsl ECM/PCM.
VACUUMPUMP/GAUGE,0 - 30 in.HgA973X - 041 -
xxxxx
EVAPCONTROLCANISTER
EVAP PURGE CONTROL SOLENOIDVALVE 2P CONNECTOR (Cl08}
Wire side offemaleterminals
(cont'd)
-21511
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Page 418 of 1395
Emission Control System
Evaporative Emission (EVAPI Controls (cont,dl
1T1456I (conro)
€VAPBYPASSSoLENOtOVALVEECM/PCM CONNECTOR A I32P)
Wire side of female terminals
VACUUMPUMP/GAUGE.0 -30 in.HgA373X -
041 -
xxxxx
EVAP BYPASS SOLENOIDVALVE 2P CONNECTOR lcorlTl
2WBS(BLU}
II
Wire side offemaletermrnats
tGlIBLK/WHT}
EVAP bypa3s solenoid valve test.(The continuation ot DTC P1456troubleshooting.l
Check the EVAP bypass sotenoid
1. Disconnect the vacuum hosefrom the EVAP two way valve,and connect a vscuum pumpto the hose,2. Connect the ECM/PCM con-nector terminal 43 to the bodyground with a jurnper wire.3. Turn the ignition switch ON 0t).4. Apply vacuum to the hose.
EVAP bypass solenoid valve/EVAP two way valve is OK. Doth6 EVAP control crnister ventshut vafve le3t lso€ page 11-2'111.
Does the valve hold vacuurn?
Check for an op€n in the wir€(2WBS line):1. Turn the ignition switch OFF.2. Disconnect the EVAP bypasssolenoid valve 2P connector.3. Check for continuity betweenthe EVAP bypass so teno idvalve 2P connector terminalNo. 2 and body ground.
Repair open in the wire betweenthe EVAP bypass solenoid valv.and ECM/PCM lA3).
Chack tor an op6n in the wirellcl line):1. Turn the ignition switch ON l).2. Measure voltage between theEVAP bypass solenoid valve2P connector terminal No. land body ground.
Replace the EVAP byps.,s solonoidvatus and O-ring3.
Ropair o,pen in the wire botwoenth6 EVAP bypa$ sotenoid vatvoand No. 15 ALTERNATOR SpSENSOR (7.5 Altuso.
2WBS (BLU}
/3
7,x
4l6o/to -/
,/ 16 1718't920 211/z3
26 272A29solT32
JUMPER WIRE
11-216
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