Page 407 of 1395

'97 model:
The scan tool indicates Diagnostic Trouble Code (DTC) P0441: Evaporative Emission (EVAP) control system
insufficient purge flow.
Description
By monitoring the purge line vacuum with the MAP sensor, the PCM can detect insufficient EVAP control system purge
flow.
Possiblo Cause
. EVAP Purge Control Solenoid Valve
. EVAP Purge Control Solenoid Valve Circuit
. EVAP Control Canister
. Vacuum Lines
. PCM
Troubleshooting Flowchart
EVAP PURGE CONTROL
SO1TNOID VALVE 2P
CoNNECTOR (C108)
(v)
YL
Wire side of female
termrnals
(cont'd)
11-205
Th€ MIL has b€en reooited on.DTC P0441 is .tored.
Problem verificationl1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neut.al) untilthe radiator fan comes on.2. Do the PCM Reset Procedure.3. Connect the SCS service con-nector,4. Test drive under following con'ditions on the road.- without any electrical load- Transmission in @ or @position- Engine speed between1 ,2OO - 2,4OO rpfi.- Decelerate from 50 mph (80
km/h)to 15 mph (24 km/h)Intermittent trilure, sydern is OKat this time. Check for Door con-nections or loose wir€3 at C108
IEVAP purge control solonoidvalvol .nd at the PCM.
ls DTC P0441 indicated?
Check tor an open in the wire (lcl
linel:1. Turn the ignition switch OFF.2. Disconnect the EVAP purge
control solenoid valve 2P con-nector.3. Turn the ignition switch ON (ll).
4. Measure voltage between bodyground and the EVAP purge
control solenoid valve 2P con-nector terminal No. '1,
R€pafu open in thc wir6 b€tw€enthG EVAP purge control solenoidvalve and the No. 15 ALTEBNA-TOR SP SENSOR (7.5 A)fuse.
ls there batlery voltage?
(To page 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 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)
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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 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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