Page 408 of 1395
Emission Control System
Evaporative Emission (EVAP) Controls (cont'dl
(From page 11-205)PCM CONNECTOR A (32PI
JUMPER wlRE
PCS IRED/YELI
Wire side of female terminais
PG1 (BLKI
Chsck th6 EVAP purgo controlsolonoid valve:'L Reconnect the EVAP purgecontrol solenoid valve 2P con-nector.2. Connect PCM connector terminals 415 and A10 with a
Chscl to. an op6n or 3hort in th€wiro (PCS lin6):Measure voltage between PCMconnector terminal A15 and bodygrouno,
Does the solenoid valve clickwhen the jumper is connected?
Chock for . .hort in tho wiJe IPCSline):1. Turn the ignition switch OFF.2. Disconnect the PCM connec-tor A (32P).
3. Disconnect the EVAP purge
control solenoid valve 2P con-nector,4. Check for continuity betweenbody ground and PCM con-nector terminal A15.
ls there battery voltage?
Rooair short in tho wir6 bctweenthe EVAP purge control 3olenoidvalvo and tho PCM (A151.
Ropair open in the wir6 betwoonthe EVAP pu]go control .olonoidv.lve end the PCM (A15).
Check the vacuum lin6:Check the vacuum lines of EVAPsystem tor misrouting, leakage,brsakago and clogging.
Are the vacuum lines OK?
(To pago 11'207)
11-206
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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 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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Page 420 of 1395
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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