Disconnest the lilP connector from the control unit.
Csvity WireTest condition
R€conn€ct tho 14P connGctor to the control unit.
Test: Desired resultPossible cause it result is not obtained
BRNAr'VHTUnder all conditionsCheck for resistance to groundl
There should be 80 - 120 o.
Faulty actuator solenoid
Poor ground (G202)
An open in the wire1BRNUnder all conditionsCheck for resistance to groundl
There should be 40 - 60 0.
11BRN/BLKUnder all conditionsCheck for resistance to ground:
There should be 70 - 110 O.
2GRY
lgnition switch ON (ll),
main switch ON and
brake pedal depressed,
then released
Check for voltage to ground:
There should be 0 V with the pedal
depressed and battery voltage with
the pedal released.
. Faulty brake switch. An open in the wire
BLKUnder all conditionsCheck for continuity to ground:
There should be continuity.
. Poor ground (G401). An open in the wire
5GRNMHT
Brake pedal depressed,
then released
Check for voltage to ground:
There should be battery voltage with
the pedal depressed, and 0 V with
the pedal released.
Blown No.52 1'15 Alfuse in the
under-hood fuse/relay box
Faulty brake switch
An open in the wire
LT GRN/
RED
Set button pushedCheck for voltage to ground:
There should be battery voltage.Blown No. 52 {'15 A} fuse in the
under-hood fuse/relay box
Faulty horn relay
Faulty sevresume switch
Faulty cable reel
An open in the wire7LT GRN/
BLK
Resume button pushed
10RED/BLU
lgnition switch ON lll)Attach to ground:
Cruise indicator light in the gauge
assembly should come on.
Elown bulbBlown No. 25 (7.5 A) tuse in theunder-dash fuse/relay box
Faulty dimming circuit in the gauge
assembly
An open in the wire
ELU^r'r'HT
lgnitjon switch ON {ll}and main switch ON;
raise the front of the
vehicle, block one wheel
and rotate the other
wheel slowly.
Check for voltage between the
ELUA/VHT @ and BLK O terminalsl
There should be 0 - 5 V or more-0 - 5 V or more repeatedly.
Faulty vehicle speed sensor (VSS)
An open in the wire
r3LT GRN
lgnition switch ON {ll}and main switch ONCheck for voltage to ground:
There should be battery voltage.
Blown No. 14 (7.5 A) fuse in theunder-dash fuse/relay box
Faulty main switch
An open in the wire
l4PNK
A'/T: Shift lever in E, EotE
lvl/T: Clutch pedal
releaseo
Check for continuity to ground:
There should be continuity.NOTE: There should be no continu-
ity when the shift lever is in otherpositions or when the clutch pedal is
oepresseo.
Faulty A/f gear position switch 1A,/TlFaulty or misadjusted clutch switch
fi{/r)Poor ground (G101)
An open in the wire
BLU
Start tho engine. turnthe main switch ON, anddrive the vehicle over 25
mph (40 km/h)with the
crurse control set
Check for voltage to ground:
There should be approx.5 V
. Faulty cruise control unit. Shod to ground
*: '98 - 00 models with Automatic Transmission.
4-39
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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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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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Troubleshooting
Troubleshooting Procedures (cont'd)
DataDescliptionOperating ValueFreezo Data
HO2S
Feedback
Loop Status
Loop status is indicated as "open" or "closed".
Closed: Based on the HO2S output, the ECM/pCM deter-mines the airlfuel ratio and controls the amount ofinjected fuel.
Open: ignoring HO2S output, the ECM/pCiM refers to sig,nals from the TP, MAP, and ECT sensors to control theamount of injected fuel.
At idle speed: closed
YES
Short Term
Fuel Trim
The airlfuel ratio correction coefficient for correcting theamount of injected fuel when HO2S feedback is in theclosed loop status. When the signal from the HO2S isweak, short term fuel trim gets higher, and the ECM/PCMincreases the amount of injected fuel. The airlfuel ratiogradually gets richer, causing a higher HO2S output.Consequently. the short term fuel trim is lowered. andthe ECM/PCM reduces the amount of injected fuel.This cycle keeps the airfuel ratio close to the stoichio-metric ratio when in closed looD status.
t:20y"
YES
Long Term
Fuel Trim
Long term fuel trim is computed from shon term fueltrim and indicates changes occuring in the fuel supplysystem over a long period.
lf long term fuel trim is higher than 1,00. the amount ofinjected fuel must be increased. lf it is lower than L00.the amount of injected fuel must be reduced.
! 20%
Intake Air
Temperature
(IAT)
The IAT sensor converts intake air temperature into volt-age and signals the ECrU/PCM. When intake air tempera-ture is low, the internal resistance of the sensorincreases, and the voltage signal is higher.
With cold engine:
Same as ambient temper-
ature and ECTYES
Throttle
Position
Based on the accelerator pedal position, the openingangle of the throttle valve is indicateo.At idle speed:
approx. 10%
lgnition
Timing
lgnition timing is the ignition advance angle set by theECM/PCM. The ECM/PCM matches ignition timing to thedriving conditions.
At idle speed: 16'1 4.
BTDC with the SCS ser-
vtce connector connected.
NO
Calculated
Load Value(cLV)
CLV is the engine load calculated from the MAp data.At idle speed:
2A - 410/o
At 2,500 rpm with no load:
13 - 260/o
YES
_
1 1_66
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