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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DATA LINK CONNECTOR {DLC) I16P}Troubleshooting Procedures, page 1 1'60PRIMARY HEATED OXYGEN SENSOR
{PRIMARY HO2SI {SENSOR 1)Troubleshooling, page 11 110
SECONDARY HEATED OXYGENSENSOR{SECONDARY HO2S) {SENSOR 2)Troubleshooting, page 1 1-1 17
'97 - 98 models:
AIR CLEANERReplacement, page 1 1'194
Troubleshooting, page 1 'l -200
THROTTLE BODY (TB)Inspection, page 11 196Removal, page 11-197Disassembly, page 1 1-'198
POWERTRAIN CONTROL MODULE(PCM) (A/TI
Troubleshooting Procedures, page 1 1-60Troubleshooting. page 1 1'82
THROTTLE CABLEInspection/Adjustment, page 1 1-1 94Installation, page 11- 195
VENTILATION (PCV) VALVEInspection, page 1 1-201FAST IDLEVALVE (A/T}
(cont'd)
1 1-5
PGM-FIMAIN RELAYRelay Testing, page 11-l87Troubleshooting. page 1'1 188
SERVICE CHECK CONNECTOR {2PITroubleshooting Procedures, page 1 1-60
,a'=_-_
WAY CATALYTIC
Inspection, page 1 1-168
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Troubleshooting
Troubleshooting Procedures
How To Begin Troubleshooting
When the Malfunction indicator Lamp (MlLl has been reported on, or there is a driveability problem, use the appropri-ate procedure below to diagnose and repair the problem.
A. When the MIL has come on:
1. Connect the Honda PGM Tester or an OBD Il scan tool to the 16P Data Link Connector (DLC) located behind theright side of the center console.
Turn the ignition switch ON (ll).
Check the DTC and note it. Also check and note
the freeze frame data.
Refer to the Diagnostic Trouble Code Chart and
begin troubleshooting.
NOTE:
. SeetheOBDll scan tool or Honda PGM Tester user's manuals for specific operating instructions.. The scan tool or tester can read the Diagnostic Trouble Codes (DTC), freeze frame data, current data, and otherEngine Control Module (ECM}/Powertrain Control Module (PCM) data.. Freeze frame data indicates the engine conditions when the first malfunction, misfire or fuel trim malfunction wasdetected. lt can be useful information when troubleshootino.
B. When the MIL has not come on, but there is a driveability problem, refer to the Symptom Chart on page 11-64.
C. DTCs will be indicated by the blinking of the Malfunction Indicator Lamp {MlL) with the SCS service connector con-nected.
Connect the SCS service connector to Service Check Connector as shown. {The 2P Service Check Connecror rslocated behind the right side of the center console.) Turn the ignition switch ON 0l).
DATA LINK CONNECTOR I16PI
1 1-60
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ll. Engine Controt Module (EcM)/Powertrain Control Module {PCM) Reset Procedure
Either of the following actions will reset the ECM/PCM.
. use the oBD ll scan tool or Honda PGM Tester to clear the ECM' s/PCM' s memory. (see the oBD ll scan tool or
Honda PGM Tester user's manuals for specific operating instructions )
. Turn the ignition switch oFF. Remove the BACK UP (RADIO) (7.5 A) fuse from the under-hood fuse/relay box for 10
seconos.
lll. Final Procedure {this procedure must be done after any troubleshooting)
1. Remove the SCS Service Connector if it is connected. lf the SCS service connector is connected. and there are no
DTCS stored in the ECM/PCM, the MIL will stay on when the ignition switch is turnsd oN (ll).
2. Do the ECM/PCM Reset Procedure.
3. Turn the ignition switch OFF
4. Disconnect the OBD ll scan tool orHonda PGM Tester from the Data Link Connector ( 16P)'
(cont'd)
1 1-61
BACK UP {RADIOI I7,5 AI FUSE
FUSE/RELAY BOX
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Powertrain Control Module Terminal Arrangement -'97 Model
FCM CONNECTOR A (32P)NOTE: Standard battery voltage is 12 V.
Wire side of lemale terminals
f€rminalnumlreJWirecolor
Telminalnama
DescriptionSignal
YELlNJ4 (No.4 FUELINJECTOR)Drives No. 4 {uel injector.With engine running: duty controlled
2BLUlNJ3 (No.3 FUELINJECTOR)Drives No. 3luel injector.
REDlNJ2 {No.2 FUELINJECTOR)Drives No.2 tuel injector.
BRNlNJl (No. l FUELINJECTOR)Drives No. 1 fuel injector.
5BLK WHTSO2SHIC (SECONDARY
HEATED OXYGEN SENSOR HEATER CONTROL)
D ves secondary heated oxygensensor heater.With ignition switch ON {ll): battery voltageWith fully warmed up engino running: dutycontrolled
6BLKAr'YHT
PO2SHTC (PRIMARY
HEATED OXYGENSENSOR HEATERCONTROL}
Drives primary heated oxygensensor heater,With ignition switch ON lll): battery voltagewith fully warmed up engine running: dutycontroll6d
I8RN/BLKLGl (LOGIC GROUND}Ground forthe PCM control circuit.Less than 1.0 V at all times
10BLKPG1 lPOWER GROUND}Ground for the PCM power circuit.
l1YEUELKIGPl lPOWER SOURCE}Power source for the PCM controlcircuit.
With ignition switch ON (ll): battery voltageWith ignition switch OFF: 0 V
12BLI(BLUIACV {IDLE AIRCONTROL VALVE}Drives IACV.With €ngine running: duty controlled
REDryEL
PCS (EVAP PURGECONTFOL SOLENOIDVALVE)
Drives EVAP purge controlsolenoid valve.
With engine running, engine coolantbelow 154'F (68"C): battery voltageWith engine running, engine coolantabove 154"F (68"C): duty controlled
16GRN/VELFLR (FUEL PUMP RELAY)Drives Iuel pump relay.0 V for two seconds after turning ignition
switch ON lll), then battery voltage
118LI(REDACC (A,/C CLUTCHRELAY}Drives Ay'C clutch relay.With comoressor ON: 0 VWith compressor OFF: baftery voltage
18GRN/ORNMIL (MALFUNCTION
INDICATOR LAMP}Drives MlL.With MIL turned ON: 0 VWith MIL turned OFF: baftery voltage
19*WHT/GRNALTC (ALTERNATOR
CONTROL}Sends alternator control signal.With tully warmed-up engine running:
battery voltageDuring driving with smallelectrical load:0 '
20YEUGRNICM (IGNITION CONTROLMODULE)Sends ignition pulse.With ignition switch ON (ll): baftery voltageWith engine running: pulses
22BRN/BLKLG2 (LOGIC GROUND}Ground tor the PCM control circuit.Less than 1.0 V at alltimes
23BLKPG2 {POWER GROUND}Ground lor the PCM power circuit.
24YEUBLKIGP2 {POWER SOURCE}Power source for the PCM controlcircuit.
With ignition switch ON (ll): battery voltage
With engine switch OFF: 0 V
27GRNFANC (RADIATOR FANCONTROL)Drives radiator {an relay.With radiator fan running: 0 VWith radiator fan stopped: baftery voltage
*: USA
{cont'd)
11-67
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Troubleshooting
PCM CONNECTOR B I25PI
Powertrain Control Module Terminal Arrangement -'97 Model (cont'dl
Wire side of female terminalsPCM CONNECTOR B I25P}NOTE: Standard battery voltage is l2 V.
1 1-68L
TerminelnumbercolorTerminalnameOescriptionSignal
1LS 1A/T CLUTCHPRESSURE CONTROLSOLENOID VALVE -)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll): duty con-trolled
2REDLS + (A"/T CLUTCHPRESSURE CONTROLSOLENOID VALVE +)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll)r duty controlled
38LU//EL
SHA (SHIFT CONTROLSOLENOID VALVE A)Drives shift control solenoid valve A.In 2nd, R position. in 2nd and 3rd gear inD4, D3 position: Battery voltageIn lst gear in D4, D3 position, in 4th gear
in D4 position: 0 V
4GRN/BLKLC B (LOCK-UP CONTFOLSOLENOID VALVE B)Drives lock-up control solenoidvalve B,With full lock-up; Baftery voltageWith half lock-up: duty controlled
5YELLC A (LOCK.UP CONTROLSOLENOID VALVE A)Drives lock-up control solenoidWith lock'up ON: battery voltageWith lock-up OFF:0 V
IPNKATPD3 (Ay'T GEARPOSITION SWITCH}Detects A/T gear position switchsignal. _
In D3 position:0 Vln any other position: battery voltage
11GRN/VVHT
SHB (SHIFT CONTROLSOLENOID VALVE 8}Drives shift control solenoid valve B.In 1st, 2nd position, in 1st and 2nd gear inD4, D3 position: Battery voltageIn R position, ;n 3rd gear in 04, D3, in 4thgear in D4 position: 0 V
12WHT/BEDILU (INTERLOCK
CONTROL UNITiDetects interlock control unh signal.With ignition switch ON (ll)and brakepedal depressed: battery voltage
GRN/BLKD4IND (04 INDICATORLIGHT}Drives Dl indicator light.With D4 indicator light turned ON: batteryvoltageWith D4 indicator light turned OFF: 0 V
14NMSG (MAINSHAFT
SPEED SENSOR GROUND}Ground tor mainshaft speed sensor.
REDNM (MAINSHAFT SPEEDSENSOR)Detects mainshaft speed sensorsrgnal,With engine running: pulses
16ATPR (A"/T GEARPOSITION SWITCH)Detects A/T gear position switchsrgnal.InRposition:0VIn any other position: battery voltage
1'lBLUATP2 (A./T GEARPOSITION SWITCH)Detects A/T gear position switchsrg nal,In 2nd position: 0 VIn any other position: battery voltage
18BRNATP1 (4,,/T GEARPOSTTTON SWTTCH)Detects A/T gear position switchsrg nal,ln lst position: 0 VIn any other position: battery voltage
22GBNNCSG (COUNTERSHAFT
SPEED SENSOR GROUND)Ground tor countershaft speedsensor,
23BLUNC (COUNTERSHAFT
SPEED SENSOR)Detects countershaft speed sensorsrgnal.With agnition switch ON (ll), and lrontwheels rotating: pulses
24YELATPD4 (M GEARPOSITION SWITCH)Detects A,/T gear position switchsrgnal.In D4 positionr 0 VIn any other position: battery voltage
25LT GRNATPNP {A/T GEARPOSITION SWITCH)Detects A/T gear position switchsignal.In park or neutral:0 VIn any other position: about 5 V
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Engine/Powertrain Control Module Terminal Arrangement - 38 - 00 Models
ECM/PCM CONNECTOR A (32P}
,/./5aIsca
,/ l,/t5ItsTs
n2ls!uCI
Wire side ot female terminalsECM/FCM CONNECTOR A {32P)NOTE: Standard baftery voltage is '12 V.
D93criptionSignal
3BLU2WBS {EVAP BYPASSSOLENOID VALVE)Drives EVAP bvoass solonoid valve.With ignirion switch ON {ll)r battery voltage
LT GRNMHTVSV {EVAP CONTROL CANISTEB VENT SHUT VALVE)D.ives EVAP controlcanisler vent shutWith ig^ition switch ON (ll): battery voltage
5',BLUCRS (CRUISE CONTROL SIG'NAL)Shift Oown signalinputfrcm cruise conWhen cruise control is used: pulses
6RED/YEL
PCS (EVAP PURGE CONTROLSOLENOID VALVE)Drives EVAP purge controlsolonoid valve.With engins running, engine coolant, below 154'F(68'C)r battery voltageWith engine running, engine coolant, above 154"F{6a'C}r duty conl.olled
8ELIOWHTSO2SHTC (SECONDARVHEATED OXYGEN SENSORHEATER CONTROL)
Drives sacondary heated oxygen sensorWith ignition switch ON (ll): banery voltageWith fully warmed up engine running: duty
10BRNSCS (SERVICE CHECX SIGNAL)Detects seNics check conneclor signal(he signalcausing a DTC indicatjon)with rhe lerminal connected:0 vWith the rerminaldisconnectedrabout 5 v or
l4'rGRN/8LKD4IND (D4INDICATOR)+3DIND (D INDICATORTIDrives D4*3. Dr'indicaior light.W,rh 04' , O" indrcator light turned O batter,
With D4*3, D*. indicator light turned OFFr0 V
16GRNI/ELFLR (FUEL PUMP RELAY)Drivss fusl pump relay.0 V for iwo seconds after ru'nin9 ign'lion swilchON lll), then banery voltage
17AL|(/REDACC (I/C CLUTCH RELAY}Drives l,/C clurch rclay.With compressor ONr0 VWith compressor OFF: battery voltage
18GRN/ORNMIL (MALFUNCTION INDICA.TOR LIGHT)Driv€s MlL.With MlLturned ON:0 VWith MIL turned OFF: battery voltage
19BLUNEP (ENGINE SPEED PULSE)Outputs engine spsed pulse.With sngine runnin9: pulses
20GRNFANC {RADIATOR FAN CONTROL)Drives r6diator fan rslay.With radaator fan running:0 VWith radaatorfan stopped: battery vollage
218LU/t/ELK-LINESends and receiv€s scan toolsignal.With ignition switch ON (ll): p'rlses
23WHT/REDSHO2S (SECONDARY HEATEDOXYGEN SENSOR. SENSOR 2iDetects secondary h€at€d oxygen sensorWith throttle fully opened from idle wilh fullywalmed up engine: above 0.6 Vwith rhrottle quickly closed: below 0-4 V
21BLU/WHTSTS (STARTER SWITCH SIG,NAL}Dotocts srarter switch signal.Whh staner switch ON (lll): batlery voltageWith srarter switch OFF: 0 V
26GBNPSPSW {P/S PsESSUFESWITCH SIGNAL)Detecrs PSP switch signal.At idle with steeing wh€el in stBighl ahead position: 0 VAt idls with nee ng wheel al full lockr banory voltage
2fBLU/BEOACS (Ir'C SWTCH SIGNAL}D€tects ly'C switch signal.With Ay'C switch ON:0 VWith l/C swil€h OFF: about 5 V
2A'\WHT/NEDSLU {INTERLOCK CONTROLUNIT)Orives interlock control unil.With ignilion switch ON (ll)and brake pedaldepressed: battery vohage
29LT GRNPTANK (FUEL TANK PRES'SURE SENSOR)Detocts fueltank pressure sensor signal.With agnition switch ON (ll) and fuel fill capopensd; about 2.5 v
GBN/FEDEL (ELD}Detects ELD signal.Wirh paaing rightstumed on at idle:about 2.5 - 3.5 VWith low beam headlights tumed on at idle:about 1.5-2.5V
GRN/WHTBKSW (BRAKE SWTTCH)Dst€cts brake switch signal.Wirh brake pedal released:0 VWith brake pedal depressed: battery vollage
13: '98 modsl
15: USA(cont'd)
11-71
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Troubleshooting
Engine/Powertrain Control Module Terminal Arrangement - '98 - 00 Models
(cont'd)
ECM/PCM CONNECTOR B {25PI
Wire side of female terminalsECM/PCM CONNECTOR B I25PI
*2t MlT*3: '98 model"4: '99 - 00 models
NOTE: Standard baftery voltage is l2
Ierminalnumb€tWire colorTerminsl nameDescriptionSignal
1YEUBLKIGPl (POWER SOURCE)Power source for the ECM/PClvlcontrol circuit.withagewith
ignition switch ON (ll): battery volt-
ignition switch OFF:0 V
BLKPG1 (POWER GROUND}Ground for the ECM/PClvl controlcircuit.Less than 1.0 V at all times
REDlNJ2 (No. 2 FUEL INJEC-roR)Drives No. 2 Iuel injector.With engine running: duty controlled
BLUlNJ3 1No. 3 FUEL INJEC-TOR)Drives No. 3Iuel jnjector.
YELlNJ4 {No.4 FUEL INJEC-TOR)Drives No. 4 fuel injector.
8*1WHTLS- (A"/T CLUTCH PRES.SURE CONTROL SOLE,NOID VALVE _ SIDE)
A,/T clutch pressure controlsolenoid valve power supplynegative terminal.
With ignition switch ON (ll): dutycontrolled
9YEUBLKIGP2 IPOWER SOURCE)Power source for the ECN,I/PCMcontrol circuit.With ignition switch ON (lll: bafteryvoltageWith ignition switch OFF:0 V
10BLKPG2 (POWER GROUND}Ground for the ECM/PCM controlcrrcurt.Less than '1.0 V at all times
' BRNlNJl (No. 1 FUEL INJECTOR)Drives No. l tuel injector.With engine running: duty controlled
YEUGRNrcM {rGNrTroN coN-TROL MODULE)Sends ignition pulse.With ignition switch ON (ll): batteryvoltageWith engine running: pulses
17*1REDLS+ (A,,IT CLUTCH PRESSURE CONTROL SOLE-NOID VALVE + SIDE)
A,/T clutch pressure controlsolenoid valve power supplypositive terminal
With ignition switch ON (ll): dutycontrolled
19*.PNK
ODIND (OVER-DRIVE
OFF INDICATOR}Drives OVER-DRIVE OFFindicator light.With OVER-DRIVE OFF indicator lightturned ON: 0 VWith OVER-DRIVE OFF indicator lightturned OFF: battery voltage
20BRN/BLKLG1 (LOGIC GROUND)Ground for the ECM/PCM controlcircuit.Less than 1.0 V at all times
WHT/BLUVBU (VOLTAGE BACKUP)Power source for the ECM/PCMcontrol circuit.Power source forthe DTC memory.
Battery voltage at all times
22BRN/BLKLG2 (LOGIC GROUND)Ground for the ECN4/PCM controlctrcutt,Less than 1.0 V at all times
23BLVBLUIACV {IDLE AIR CON.TROL VALVE)Drives IAC valve.With engine running: duty controlled
11-72
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