Fuel and Emissions
Special Tools ...................... 11-2
Component Locations
lndex ...................... ....,.... 11-3
Svstem Description
Vacuum Connections ...........,....,.,................. 1 1-9
Electrical Connections ................................... 1 1-15
System Connectors .,.,,.,............................,.,. 1 1-36
Troubleshooting
Troubleshooting Procedures,.,..................... 11-60
Engine Control Module/Powertrain ConttolModule Terminal Arrangement .............., 11-67
Diagnostic Trouble Code Chart .................... 1 t-75
How to Read Flowcharts .......,.....,.,............... I 1-79
PGM-Fl System
System Description .................,.,.,,,............... 1 1-80
Troubleshooting Flowcharts
Engine Control Module/PowertrainControl Module ........11-52
Manifold Absolute Pressure Sensor ............. 11-90
Intake Air Temperature Sensor .................... 1 1-95
Engine Coolant Temperature Sensor .,..,.,.... 1 1-99
Throttle Position Sensor ...........,.....,.,.,..,...... I 1'103
Primary Heated Orygen Sensor (Sensor 1) ... 11-110
Secondary Heated Oxygen Sensor{Sensor 2l .................. 1 1-117
Heated Oxygen Sensor Heater ..................... 11-121
Fuef Supply System ......11-124
Random Misfire ,....,.,..... 11-126
Mistire Detected in One Cylinder .....-........... 11-128
Knock Sensor ................ 11-130
CKP/TDC/CYP Sensor .................................... 1 1-131
Vehicle Speed Sensor ...............................,.... 1 1-135
Barometric Pressure Sensor .....,...,...,.,,........ 1 1-137
Electrical Load Detector ...,.,.......................... 1 1-138
CKF Sensor ................,.,, '11-112
ECM/PCM lnternaf Circuit ............................. 11'117
HO2S Replacement .,.,.,. 11-148
ldle Control System
System Description ............ 11-149
Troubleshooting Flowcharts
ldle Control System ...... 11-150
fdle Air Control Valve ......................,............. 11-152
Air Conditioning Signal ................................. I 1-155
Alternator FR Signal ...................................... 1 1-159
Starter Switch Si9na1 .................................... t l-161
Power Steering Pressure Switch Signal ...... 11-162
Brake Switch Si9na1 ...................................... 11-166
Fast ldle Thermo Valve .,.,.............................,.,.,. 11-168
ldle speed setting .............. 11-169
Fuel Supply System
Fuel Lines ............................ 11-171
Fuef Tube/Ouick-Conneci Fittings ..................... 11 -175
System Description ............ 11-178
Fuel Pressurg ...................... 11-178
Fuel Iniectors ................,..... 11-179
Fuel Pressure Re9u1ator .............................,.,...., f 1-181
Fuef Fifter ....,.,.,.,,,,.,............11-142
Fuel Pump ........................... 11-183
Fuel Gauge .......................... 11-184
Fuel Gauge Sending Unit ................................... I 1-185
Low Fuel Indicator System ...........,.,..,............... 1 1-185
PGM-FI Main Relay ............. 11-187
Fue|Tank................ ............. 11-191
Intake Air System
System Description ............ 11-193
Air Cleanel ,.,.,..................... 11-194
Throttle Cable ..................... 11-194
Throttle Body........ .............. 11-196
Emission Control System
System D$cription ...,....,.,. 11-199
Tailpipe Emission ............... 11-199
Three Way Catalytic Converter ..................,.,...,, 11-199
Positive Crankcase Ventilation System .,.,,,,.,.., 11-2O1
Evaporative Emission Controls .........,.,.,............ 11-203
www.emanualpro.com
Fuel Supply System
System Description
The fuel supply system consists of a fuel tank, in-tank
high-pressure fuel pump. PGM-Fl main relay, fuel filter,
fuel pressure regulator, fuel injectors, and fuel delivery
and return lines. This system delivers pressure-regulat-
ed fuel to the fuel injectors and cuts the fuel delivery
when the engine is not running.
Fuel Pressure
Relieving
Before disconnecting fuel pipes or hoses, release pres-
sure from the system by loosening the 12 mm banjo
bolt on the too of the fuel filter.
Do not smoke while working on the fuel system.
Ke€p open flames or sparks away from your work
area,
Be sure to relieve fuel pressure while the ignition
switch is off.
Write down the frequencies for the radio's preset
buttons.
Disconnect the battery negative cable from the bat-
tery negative terminal.
Remove the fuel fill cap.
Use a box end wrench on the 12 mm banjo bolt at
the fuel filter while holding the fuel filter with anoth-
er wrench.
Place a rag or shop towel over the '12 mm banjo bolt.
Slowly loosen the 12 mm banjo bolt one complete
rurn 12 mm BANJoBOLT
1.
SHOP TOWEL
NOTE: Replace the washers whenever the 12 mm
banio bolt is loosened or removed.
11-178
Inspection
1, Relieve fuel pressure.
2. Remove the 12 mm banjo bolt on the fuel filter while
holding the fuel filter with another wrench. Attach
the 12 mm fuel pressure adapter bolt and the special
tool.
FUEL PRESSUREREGULATON
FUELPRESSUREGAUGE07406 - 0040001
The illustration shows'97 - 98 models,'99 - 00 models are similar.
Start the engine. Measure the fuel pressure with the
engine idling and the vacuum hose of the fuel pres-
sure regulator disconnected from the fuel pressure
regulator and pinched. lf the engine will not start,
turn the ignition switch on (ll), wait for two seconds,
turn it off, then back on again and read the fuel
pressure.
Pressure should be:'97 - 98 mod€ls:
260 -31O kPa 12.7 - 3.2 kgf/cm,, 38 - 46 psil'99 - 0O models:
270 - 32O kPa Q.A - 3.2 kgf/cm' , ifo - /U psil
Reconnect vacuum hose to the fuel pressure regulator.
Prgs3ure should be:'97 - 98 models:
210 - 25O kPa 12.1- 2.6 kgf/cm' , 30 - 37 psi)'99 - 00 models:
22O -26iJ kPa 12.2 - 2.7 kgt/cm' , 31 - 38 psi)
lf the fuel pressure is not as specified, first check the
fuel pump (see page 11- 183). lf the fuel pump is OK,
check the following:
. lf the fuel pressure is higher than specified,
inspect for:- Pinched or clogged fuel return hose or line.- Faulty fuel pressure regulator (see page 11-
181).
. lf the fuel pressure is lower than specified. inspect
for:- Clogged fuel filter.- Faulty fuel pressure regulator (see page 11-
1811.- Fuel line leakage.
www.emanualpro.com
'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)
www.emanualpro.com
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
www.emanualpro.com
'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
'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
Master Cylinder/Brake Booster
Removal/lnstallation
1, Disconnect the brake fluid level switch connectors.
2. Remove the reservoir cap from the master cylinder.
3. Remove the brake fluid from the master cvlinder
reservoir with a syringe.
4. Disconnect the brake lines from the master cylinder.
To prevent spills, cover the line joints with rags or
shop towels.
5. Remove the master cylinder mounting nuts and
wasners.
6. Remove the master cylinder from the brake booster.
CAUTION: Be careful not to bend or damage the
brake lines when removing the master cylinder.
Do not spill brake fluid on the vehicle; it may dam.
age the paint; it brake fluid does cont.ct the paint,
wash it oft immediately with water.
7. Disconnect the vacuum hose from the brake booster.
8. Remove the cotter pin and clevis pin from the clevis.
Do not disconnect the clevis by removing it from
the operating rod of the brake booster. lf the clevis
is loosened, adjust the pushrod length before
installing the brake booster (see page 19-15).
To Front Caliper (Without ABS)
\\
15 N.m {1.5 kgtm, vAcuuM HosE
r r rbf.ft) |
/ | BRAKE FLUTD LEvEL
/l /
swrrcHcoNNEcroRs
/ I I I COTTER PIN
I I / neotace
l,/-- ro Rear wheet cylinders / | I
h ./-''' /. I I IYli //*s (.S
I /r:
9. Remove the four booster mounting nuts.'10. Pull the brake booster forward until the clevis is
clear of the bulkhead.
11. Remove the brake booster from the enqine com-
panment.
12. Install the brake booster and master cylinder in the
reverse order of removal, and note these items:
. When connecting the brake lines, make sure that
there is no interference between the brake lines
and other parts.
. Be careful not to bend or damage the brake lines
when installing the master cylinder.
. lf replacing the master cylinder or brake booster,
check and adjust the pushrod clearance before
installing the master cylinder (see page 19-14).
Fill the master cylinder reservoir, and bleed the
brake system (see page 19-7).
After installation, check the brake pedal height and
brake pedal free play (see page 19-5), and adjust if
necessary.
13 N.m 11.3 kg{.m,I rbf.ft)
13.
14.
To Master Cylinder(Without ABS)To Modulator Unit(with ABs)@-\
\
^ To Front Caliper
9i\.
-#qCLEVIS PIN
):-,/
PROPORTIONING CONTROL VALVE
MASTER CYLINDER
15 N.m (1.5 kgf.m, 11 lbl.ftl
BRAXE BOOSTER
www.emanualpro.com
6.
7.
8.
lf the clearance between the gauge body and
adjusting nut is 0.4 mm (0.02 in), the pushrod-to-
piston clearance is 0 mm. However. if the clearance
between the gauge body and adjusting nut is 0 mm,
the pushrod-to-piston clearance is 0.4 mm (0.02 in)
or more. Therefore it must be adjusted and
recheck€d.
lf clearance is incorrect, loosen the star locknut, and
turn the adjuster in or out to adjust.
. Adjust the clearance while the specified vacuum
is applied to the booster.
. Hold the clevis while adjusting.
Tighten the star locknut securely.
Remove the special tool.
0 - 0.4 mm (0 - 0.02 inl
Adjust the pushrod length as shown if the
is removed,
booster
11610.5 mm{4.6 t 0.02 inl
PUSHRODLOCKNUT1.5N.m 11.5 kgf.m. '11 lbtfl)
Install the master cylinder (see page 19-13).
9.
STAR LOCKNUT22 N.m12.2 kgt m. 16 lbtftl
10.
(Check valve is built-in)
Brake Booster Inspection
FunctionalTest
1. With the engine stopped, press the brake pedal sev-
eral times to deplete the vacuum reservoir. thenpress the pedal hard, and hold it for 15 seconds. lf
the pedal sinks, either the master cylinder is
bypassing internally, or the brake system (master
cylinder, lines, modulator, proportioning valve. or
caliper) is leaking.
2. Start the engine with the pedal pressed. lf the pedal
sinks slightly. the vacuum booster is operating nor-
mally. lf the pedal height does not vary, the booster
or check valve is faultv.
3. With the engine running, press the brake pedal light-
ly. Apply just enough pressure to hold back auto-
matic transmission creep. lf the brake pedal sinks
more than 10 mm (3/8 in.) in three minutes, the mas-
ter cylinder is faulty. A slight change in pedal height
when the Ay'C compressor cycles on and off is nor-
mal. (The Ay'C compressor load changes the vacuum
available to the booster.)
Leak Test
1.Press the brake pedal with the engine running, then
stop the engine. lf the pedal height does not vary
while pressed for 30 seconds, the vacuum booster is
OK. lf the pedal rises, the booster is faulty.
With the engine stopped, press the brake pedal sev-
eral times using normal pressure. When the pedal is
first pressed. it should be low, On consecutive appli-
cations, the pedal height should gradually rise. lf thepedal position does not vary. check the booster
check valve.
Boostor Chock Valve Test
1. Disconnect the brake booster vacuum hose at the
booster.
2. Start the engine, and let it idle. There should be vac-
uum. lf no vacuum is available, the check valve is
not working properly. Replace the brake booster
vacuum hose and check valve. and retest.
ERAKE BOOSTERVACUUM HOSE
www.emanualpro.com