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
www.emanualpro.com
Page 411 of 1395
'98 - 00 mod€ls:
The scan tool indicates Diagnostic Trouble Code (DTC) P0452: A low voltage problem in the Fuel Tank Pressure
sensof.
The fuel tank Dressure sensor converts fuel tank absolute pressure into electrical signals and inputs the ECM/PCM.
OUTPUTVOLTAGEtvl{.5
0,5-? KPA(-50 mmHg,-2 in.Hgl
+7 kPr
l5O mmHg,2 in.Hgl
PRESSURE
ECM/PCM CONNECTOR A (32P)
Wire side ot female terminals
FUEL TANKPRESSURE SENSOR3P CONNECTOR tc6a6l
voc2(YEL/BLUI
Wire side ol fsmale terminals
(cont'd)
11-209
Th. MIL has been reoorted on.DTC m452 is stored.
Check the vacuum lin6:Check the vacuum lines of the fueltank pressure sensor for misrouting, leakage, breakage and clog-ging.
Are the vacuum lines OK?
Problem veriticstion:1. Do the ECM/PCM ResetProcedure-2. Remove the luelfillcap.3. Turn the ignition switch ONfl r).4. Monitor the FTP Sensor volt'age with the Honda PGMTester, or measure voltagebetween body ground andECM/PCM terminalA29.Intermittent failuro, system is OKat this lima. Chack lor Door con-nections or loose wi.es at C580llocrted rt access panell, C646lluel tank Daessure sensor) andat the ECM/PCM.
ls lhere approx. 2.5 V?
Check lor an open in wir€ lVeC2line):1. Turn the ignition switch OFF.2. Reinstallthe fuel fill cap.3. Disconnect the fuel tank pres-
sure sensor 3P connector,4. Turn the ignition switch ON (ll).
5- Measure voltage between thefLrel tank pressure sensor 3Pconnector No. 1 terminal andNo.2 terminal.
Replir opon in the wire b€tw€enth6 tuel tank pressure lensot andthe ECM/PCM {A29).ls there approx. 5 V?
YES
(To page 11-210)
www.emanualpro.com
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
www.emanualpro.com
Page 413 of 1395
'98 - 00 modals:
The scan tool indicates Diagnostic Trouble Code (DTC) P0453: A high voltage problem in the Fuel Tank Pressure
sensor.
ECM/PCM CONNECTOR A {32PI
Wire sido ot fema16 t€rminals
FUEL TANXPf,ESSUBE SENSOR3p CONNECTOR {C6,a6l
vcc2IYEL/BLUI
sG2IGRN/BLKI
sG2(GRN/BLK}
Wire side ot female terminals
PTANKILT GRNI
(cont'd)
11-211
PTANK ILT GRN)
123
Thc MIL has b6on ropottcd on.DTC mia53 is dorcd.
Ch6ck tho vacuum linos:Check the vacuum lines of the
fuel tank pressure sensor lor mis-
routing, leakage, breakage and
cloggrng.
Are the vacuum lines OK?
Problorn verif ication:1. Do the ECM/PCM ResetProcedute.2. Remove the fuel fill cap.
3. Turn the ignition switch ON
{[).4. Monitor the FTP Sensor volt-age with the Honda PGM
Tester, or measure voltagebetween body ground and
ECM,PCM terminal429.Intarmittent tailuro, sv3iom b OKat this timo. Chock for poor con-nection3 or loo$ wire3 at C580(locstod .t .cc$r p.nell, C6a6(fucl tank pros3ure son3orl and.t the ECM/FCM.
ls there approx. 2.5 V?
Check lor an open in tho wiro
lSG2lin6l:1. Turn the ignition switch OFF.
2. R6installthe Iuel fill cap.3. Disconnect the Iu6l tank pres_
sure sensor 3P connector,4. Turn the ignition switch ON (ll).
5. M€asure voltago between thetuel tank pressure sensor 3P
connector terminals No. '! andNo.2.
Replir op€n in th. wi.c b€{weentha fuel tank Dio'sute sansot andtho EC|,/PCM {Cl8}.ls there approx. 5 V?
Ch€ck for an opon in tho wiro(PTANK linel:Measure voltage between thefuel tank pressure sensor 3P con-nector No. 3 terminal and No. 2terminal.
ls there approx. 5 V?
\To page 11-212)
www.emanualpro.com
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
www.emanualpro.com
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
www.emanualpro.com
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
www.emanualpro.com
Page 421 of 1395
'98 - 00 mod€ls:
The scan tool indicates Diagnostic Trouble code (DTc) P1457: Evaporative Emission (EVAP) Control system leak
detected (EVAP control canister system).
Troubl6shooting Flowchart('98 model only)_]
I
- The MIL has been rePorted on.- DTC P1,157 is storod.
Do the fuel tank Pressure sensor
test {see page 11-214).
ls the {ueltank pressure sensor OK?
Do the EVAP Purge contlol
solenoid valve test lsea Page 1l_
220t.
(cont'dl
11-219
www.emanualpro.com
