13. Remove the upper radiator hose, heater hose and
water bypass hose.
WATER BYPASS
UPPEBRADIATORHOSE
17
HEATERHOSE
Remove the engine wire harness connectors and
wire harness clamps from the cylinder head and the
intake manifold.
o Four fuel injector connectors
. Engine coolant temperature (ECT) sensor con-
neclor
. Radiator fan switch connector
. Coolant temperature gauge sendlng unlt connec-
tor
. Throttle position sensor connector
. Manifold absolute pressure {MAP) sensor con-
nector
Primary heated oxygen sensor (primary HO2S)
connector
ldle air control (lAC) valve connector
Distributor connector
Remove the spark plug caps and distributor from the
cylinder head.
Remove the cruise control actuator (see section 4).
Support the engine with a jack, then remove the
upper bracket. Make sure to place a cushion
between the oil pan and the iack (see page 6-10).
a
18. Remove the cylinder head cover.
19. Inspect the timing belt (see page 6-9).
CYLINDER
(cont'd)
6-19
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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
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Component Locations
lndex
'97 - 98 models:
MANIFOLD ABSOLUTEPRESSURE IMAP} SENSORTroubleshooting, Page 1 1-90
THROTTLE POSITION (TP}
SENSORTroubleshooting, page 1 1-103
toLE AtR CONTROL llAcl VAI-VE
Troubleshooting, page 1 1-152
EVAPORATIVE EMISSION (EVAP)
CONTROL CANISTER VENT SHUTVALVE t'98 mod€llTroubleshooting, page 11'213
INTAKE AIR TEMPERATUREIIATI SENSORTroubleshooting. page 1 'l -95
ELECTRICAL LOADDETECTOR IELD) (USA modol)Troubleshooting, page 1 1-138
VEHICLE SPEEDSENSOR (VSS)
Troubleshooting,page 11'135
CRANKSHAFTPOSTTtON/
POWER STEERING PRESSURElPsPl swtrcHTroubloshooting, page 1 1-162
TOP OEAD CENTER/CYLINDERPOStTtON{CKP/TDC/CYP} SENSOR(Built into the distributor)Troubleshooting, page 1 l-131
CMNKSHAFT SPEEDFLUCTUATION ICKF} SENSORTroubleshooting. page 1'!-142
ENGINE COOLANTTEMPERATUREIECTI SENSORTroubleshooting, page 11 99
EVAPORATIVEI€VAP) PURGE CONTROLSOLENOID VALVETroubf eshooting, page 1 1'2o5, 213
(cont'd)
11-3
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Component Locations
Index (cont'dl
39 - 00 models:
MANIFOLD ABSOLUTEPRESSURE IMAPISENSORTroubleshooting, page 1 1-90
THROTTLE POSITION {TP)SENSORTroubleshooting, page 1 1-103
IDLE AIR CONTROL OACI VALVETroubleshooting, page 1 1-152
EVAPOBATIVE EMISSION {EVAPICONTROL CANISTER VENT SHUTVALVETroubleshooting, page 1 1-213
EVAPORATIVE EMISSION(EVAPI PURGE CONTROI-SOLENOID VALVETroubleshootang, page 1 1-2'13
ELECTRICAL LOAOOETECTOR {ELD) IUSA modet)Troubleshooting, page I 1-138
INTAKE AIR TEMPERATURE(IAT) SENSORTroubleshooting, page 11 95
POWEB STEERING PRESSUREtPsPt swtTcHTroubleshooting, page 11 162VEHICLE SPEEDSENSOR IVSSITroubleshooting,page 11'135
CRANKSHAFTPOSTTTON/TOP OEAD CENTER/CYLINDERPOStTtON{CKP/TDC/CYP) SENSOR(Built into the distributor)Troubleshooting, page 11 131
CRANKSHAFT SPEEDFLUCTUATION ICKN SENSORTroubleshooting, page 1 1-142
SENSORTroubleshooting, page '11 130
ENGINE COOLANTTEMPERATURE{ECT)SENSORTroubleshooting, page 11 99
11-4
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System Description
Vacuum Connections (cont'dl
'97 model:
ENGINECOOLANT
ITr|ll
O PRIMARY HEATED oxYGEN sENsoR {PRIMARY Ho2s,SENSOR lt
O SECONDARY HEATED oxYGEN sENsoR {SECoNDARYHO2S. SENSOR 2l€) MANIFOLD ABSOLUTE PRESSURE (MAPI SENSOR@ ENGINE cooLANT TEMPERATURE {EcT} sENsoRO INTAKE AIR TEMPERATURE (IAI} sENsoR@ CRANKSHAFT SPEED FLUCTUATION ICKFI SENSORO |DLE ArR coNTRoL {tAc)vALvE@ FAST IDLE THERMo vALvEO THRoTTLE EoDY ITB)@ FUEL INJEcTonO FUEL PULSATIoN oAMPER@ FUEL FILTEn(} FUEL PRESSURE REGULATOR
FUEL PUMPFUEL TANKFUEL TANK EVAPORATIVE EMISSION (EVAPIVALVEAIR CLEANERRESONATORPOSITIVE CRANKCASE VENTILATION {PCVI VALVEEVAPORATIVE EMISSION {EVAP} PURGE CONTROLSOI.'ENOID VALVEEVAPORATIVE EMISSION {EVAP) CONTROL CANISTEREVAPORATIVE EMISSION {EVAPI TWO WAY VALVETHREE WAY CATALYTIC CONVERTER (TWC)
@(D(D
o@(}
@
@@@
1 1-10
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System Description
Vacuum Connections (cont'dl
'99 - q) models:
ENGINECOOLANT
t
o
o
o@
o@@@@@@@@@(t
PRIMARY HEATED OXYGEN SENSOR IPRIMARY HO2S,SENSOR 1lSECONDARY HEATED OXYGEN SENSOR {SECONDARYHO2S. SENSOR 2lMANIFOLD ABSOLUTE PRESSURE (MAPI SENSORENGINE COOLANT TEMPERATURE IECN SENSORINTAKE AIR TEMPERATURE IIATI SENSORCRANKSHAFT SPEED FLUCTUATION {CKF) SENSORKNOCK SENSOR (KS}
IDLE AIR CONTROL IIACI VALVEFAST IDLE THERMO VALVE {A/T}THROTTLE BODY (TB}
FUEL INJECTORFUEL PULSATION DAMPERFUEL FILTERFUEL PRESSURE REGULATORFUEL PUMPFUEL TANKFUEL TANK EVAPORATIVE EMISSION (EVAPI VALVE
AIR CLEANERRESONATORPOSITIVE CRANKCASE VENTILATION (PCV} VALVETHREE WAY CATALYTIC CONVERTER ITWCIEVAPORATIVE EMISSION {EVAPI CONTROL CANISTEREVAPORATIVE EMISSION IEVAPI PURGE CONTROLSOLENOID VALVEEVAPORATIVE EMISSION {EVAPI CONTROL CANISTEFVENT SHUT VALVEEVAPORATIVE EMISSION IEVAPI TWO WAY VALVEEVAPONANVE EMISSION {EVAPI AYPASS SOLENOIDVALVEFUEL TANK PRESSURE SENSOBEVAPORATIVE EMISSION IEVAPI THREE WAY VALVEPURGE JOINT
@@@@@@
@
@@
@@@
11-14
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Troubleshooting
Troubleshooting Procedures (cont'dl
Symptom Chart
Listed below are symptoms and probable causes for problems that DO NOT cause the Malfunction Indicator Lamp (MlL) tocome on. lf the MIL was reported on, go to page 11-60.Troubleshoot each probable cause in the order listed (from left to right) until the symptom is eliminated,The probable cause and troubleshooting page reference can be found below.
Other Probable Causes for an engine that will not start:- Compression- Intake air leakage- Engine locked up- Timing belt- Starting system- Overheating- Battery
SYMPTOMPROBABLE CAUSE
Engine will not sta rt4, 2,3,5,20, 't5, 1
Hard starting2, 4, 12,17, 14, 't9
Cold fast idle too low7, a,9, 6, 17
Cold fast idle too high7,8,9,11,10
ldle speed fluctuates9,7,8, 't1, 10
Misfire or rough runningTroubleshoot for misfire on pages '11-126, 1|21LOl/\/ power2, 10,11, 13, '17, 18,20
Engine stalls2, 4, 12,1,20,9,5, 't6
Probable Cause List (For the DTC Ch8rt, see page ll-75.)
Probable CausePageSystem
Engine controt ruoaute (ecvtffi'I11-42
I 1-178Fuel oressure
PGM-Fl main relav
lgnition system
Crankshatt Position/Top Dead Center/Cylinder position sensor circuit
Intake Air Temperature (lAT) sensor ctrculr
ldle Air Control (lAC) Vatve
Fast idle thermo valve
ldle speed adjustment
Throttle body
Throftle cable
Manifold Absolute P."""rr"ffi
Throftle Position (TP) sensor
Barometric pressur" (gnno-
Ay'T gear position signal
Brake switch signal
Air Cleaner
Three Way Catalytic Converter (TWC)
Evaporative emission (EVAP) control
Contaminated fuel
1 1- 187
Section 4
5't1-'t31,146
6I ' t-95
711-152
81'l-168
1 1- 169
1011-196'1111-'194
12'1 'l -90
1 1- 103
1411-137
15Section 14
161 1- 166
17r 1-194
181 1,199'1911-203
20
11-64
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ECM/PCM Data
By connecting the OBD ll scan tool or the Honda PGM Tester to the 16P data link connector (OLC), various data can be
retrieved from the ECM/PCM. The items listed in the table below conform to the SAE recommended practice
The Honda PGM Tester also reads data beyond that recommended by SAE.
understanding this data will help to find the causes of intermittent failures or engine problems.
NOTE:
The ',operating values" given below are approximate values and may be different depending on the environment and
the individual vehicle.
Unless noted otherwise. "at idle speed" means idling with the engine completely warmed up, transmission in position
Park or neutral and the A,./C and all accessories turned otf.
DataDesc.iptionOp€rating ValuoFreeze Data
Diagnostic
Trouble Code
(DTC)
lf the ECM/PCM detects a problem, it will store it as a
code consisting of one letter and tour numbers
Depending on the problem, an SAE-defined code (Poxxx)
or a Honda-defined code (P'lxxx) will be output to the
tester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECN4/PCN4 computes engine speed from the signals
sent from the Crankshaft Position sensor.
This data is used for determining the time and amount of
fuel iniection.
Nearly the same as
tachometer indication
At idle speed:'97 - 98 models:
750 t 50 rpm'99 - 00 models:
730 f 50 rpm
YES
Vehicle SpeedThe ECM/PCM converts pulse signals from the Vehicle
Speed Sensor (VSSI into speed data.
Nearly the same as
speedometer indicationYES
Manifold
Absolute
Pressure (MAP)
The absolute pressure caused in the intake manifold by
engine load and speed.
With engin6 stopped:
Nearly the same as atmo-
spheric pressure
At idle speed:
2a - 41 kPa {210 - 310
mmHg, 8.3 - 12.2 inHg)
YES
Engine Coolant
Temperature
{ECT)
The ECT sensor converts coolant temperature into volt-
age and signals the ECM/PCM. The sensor is a thermistor
whose internal resistance changes with coolant tempera-
ture. The ECM/PCM uses the voltage signals from the
ECT sensor to determine the amount of injected fuel
With cold engine:
Same as ambient temPer-
ature and IAT
With engine warmed uP:
approx. 163 - 2'12'F
(73 - 100"c)
YES
Heated Oxygen
Sensor (HO25)
(Primary,
Sensor 1)
(Secondary
Sensor 2)
The Heated Oxygen Sensor detects the oxygen content in
the exhaust gas and sends voltage signals to the
ECMiPCM. Based on these signals, the ECM/PCM controls
the airlfuel ratio. When the oxygen content is high (that is.
when the ratio is leaner than the stoichiometric ratio), the
voltage signal is lower.
When the orygen content is low (that is, when the ratio
is richer than the stoichiometric ratio), the voltage signal
is higher.
0.0 - 1.25 V
At idle speed:
about 0.1 - 0.9
NO
(cont'd)
1 1-65
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