Page 232 of 1139

Vacuum Hose Routing
I
O AIR FUEL RATIO IA/F) SENSOR {SENSOR 1}O SECONDARY HEATED OXYGEN SENSORISECONDARY HO2S} {SENSOR 2}
O MANIFOLD ABSOLUTE PRESSURE (MAPI SENSORO ENGINE COOLANT TEMPERATURE {ECT) SENSORO INTAKE AIR TEMPERATURE (IAT) SENSORO CRANKSHAFT POSITION (CKP) SENSORO KNOCK SENSORO CAMSHAFT POSITION (CMPI SENSOR BITOP DEAD CENTER ITDC) SENSOR)
O CAMSHAFT POSITION ICMPI SENSOR A@ IDLE AIR CONTROL (IACI VALVEO THRONLE BODY.O INJECTOR@ FUEL PULSATION OAMPER[I FUEL FILTER@ FUEL PRESSURE REGULATOR@ FUEL PUMP@ FUEL TANK
@ RESONATOR(9 AIR CLEANER@ POSITIVE CRANKCASE VENTILATION {PCVI VALVE@ THREE WAY CATALYTIC CONVERTER@ EVAPORATIVE EMISSION {EVAPI CANISTER@ EVAPORATIVE EMISSION {EVAP) CANISTERPURGE VALVE{} EVAPORATIVE EMISSION (EVAPI CANISTERVENT SHUT VALVE{' EVAPORATIVE EMISSION {EVAP) TWO WAY VALVE@ EVAPORATIVE EMISSION IEVAPI BYPASSSOLENOID VALVE@ FUEL TANK PRESSURE (FTP) SENSOR@ EVAPORATIVE EMISSION IEVAP} VALVE@ FUEL TANK VAPOR CONTROL VALVE60) FUEL TANK VAPOR RECIRCULATION VALVEO INTAKE AIR BYPASS CONTROL THERMAL VALVE
(cont'd)
11-25
Page 233 of 1139

Fuel and Emissions Systems
System Descriptions (cont'd)
PGM-FI System
The Programmed Fuel Injection (PGM-Fl) system is a
sequential multiport fuel injection system.
Air Conditioning {A/C) Compressor Glutch Relay
When the ECfM receives a demand for cooling from the
Ay'C system, it delays the compressor from being
energized, and enriches the mixture to assure smooth
transition to the AVC mode.
Air Fuel Ratio lA/Fl Sensor
The Ay'F Sensor operates over a wide airlfuel range. The
Ay'F Sensor is installed upstream of the TWC, and sends
signals to the ECM which varies the duration of fuel
injection accordingly.
SENSORTERMINALS
HEATERTERMINALS
Barometric Pressure {BAROI Sensor
The BARO sensor is inside the ECM. lt convens
atmospheric pressure into a voltage signal that the ECM
uses to modify the basic duration of the fuel injection
discharge.
ztRcoNtaELEMENT
HEATER
11-26
\,
Camshaft Position (CMPI Sensor B (Top Dead Center(TDCI Sensor)
The CMP sensor B (TDC sensor) detects the position of
the No. 1 cylinder as a reference for sequential fuel
injection to each cylinder.
Crankshaft Position (CKPI Sensor
The CKP sensor detects crankshaft soeed and
determines ignition timing and timing for fuel injection
of each cylinder as well as detecting engine misfire.
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a temperature dependent resistor(thermistor). The resistance of the thermistor decreases
as the engine coolant temperature increases.
MAGNET
TERMINAL
Page 236 of 1139

wEc/wc
The i-WEC has a VTC (Variable Valve Timing Control) mechanism on the intake camshaft in addition to the usual
VTEC.
This mechanism improves fuel efficiency and reduces exhaust emissions at all Ievels of engine speed, vehicle speed.
and engine load.
The VTEC mechanism changes the valve lift and timing by using more than one cam profile.
The VTC changes the phase of the intake camshaft via oil pressure. lt changes the intake valve timing continuously.
HIGH
i
LOW <-ENGINE SPEED
Drivino ConditionVTC ControlDescriDtion
Qr Light-loadBase PositionCam angle is retarded to reduce the entry of exhaust
gas into the intake port and to achieve stable fuel
consumDtion durinq lean bu rn.
?l M ed iu m/h ig h-loadAdvance ControlCam angle is advanced for EGR effect and to reduce
this pumping loss. The intake valve is closed quickly
to help reduce the entry of airlfuel mixture into the
intake port and improve the charging effect.
€) High speedAdvance-Base PositionCam phase angle is controlled for optimum valve
timinq and maximum enoine oower.
{cont'd)
11-29
Page 238 of 1139
System Diagram
INTAKE
CMP SENSOR A
BRN/YELBLU/WHT
BLU/WHT
BLK/WHT
GRN/YEL
BLU/BLK
From No. ilACC {10A) fuse
VARIOUSSENSORS
CAMSHAFT -:-
BLK
It
Camshaft Position {CMP} Sensor
The CMP sensor detects camshaft angle position for the VTC system.
{cont'd}
11-31
:5i.T,""
Page 256 of 1139
PGM-FI System
Component Location Index
CAMSHAFT POS]TION {CMP) SENSOR B(TOP DEAD CENTER (TDC}SENSORITroubleshootina. oaoe 1 1-95Replacement, p;ge 1-1.1 14
ELECTRICAL LOADDETECTOR {ELDITroubleshooting,page 1'l -92
INTAKE AIR TEMPERATURE{IATI SENSORTroubleshooting,page 'l'l-55
Replacement, page 11-'l 15
f- \
rl
KNOCK SENSORTroubleshooting, page 1 1-77Beplacement, page 11 115
ENGINE COOLANT TEMPERATURE(ECTI SENSORTroubleshooting, page 1 1-57Replacement, page 11 114
MANIFOLD ABSOLUTE PRESSURE(MAP) SENSORTroubleshooting, page 1 1-52
THROTTLE POSITIONITP} SENSORTroubleshooting, page 11-60CRANKSHAFT POSITIONICKPISENSORTroubleshooting, page'l 1-78Beplacement, page 1 1-'l 16
AIR FUEL RATIO {A/F)SENSOR ISENSOR 1}Trorrbleshooting, page 1 1-84Replacement, page 11- 1 13
{cont'd)
ii'- r'1
.I11 ---:,I''.!,i(..,.?:fir-J-
.....,..:--.
11-49
Page 278 of 1139

DTC P0300: Random Misfire and Any Combination of the Following:
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cvlinder Misfire
DTC P0303: No, 3 Cvlinder Misfire
DTC P0304: No. 4 Cvlinder Misfire
NOTE:. lfthe misfiring is frequent enough to trigger detection of increased emissions during two consecutive driving cycles.
the MIL will come on, and DTC P0300 (and some comlrination of P0301 through P0304) will be stored.. lf the misfiring is frequent enough to damage the catalyst, the MIL will blink whenever the misfiring occurs, and OTC
P0300 (and some combination of P0301 through P0304) will be stored. When the misfirlng stops, the MIL will remain
on.
1. Troubleshoot the following DTCs first if any of them were stored along with the random misfire DTC(s):
P0'107, P0108, P1128, P1129r N4anifold absolute pressure (MAP) sensor
P0111. P0'172t Fuel svstem
P0335. P0336: Crankshaft position (CKP) sensor
P0505: ldle control system
P1 149, Pl 162, P1 163, P1 164, P 1 165: Air fuel ratio (Ay'F) sensor
P1259: VTEC system
P1361, P1362: Camshaft position (CMP) sensor B {Top dead center (TDC) sensor)
P1519: ldle air control (lAC) valve
2. Test-drive the vehicle to verify the symptom.
3. Findthesymptom inthechart below, and dothe related procedures in the order listed until you find the cause.
SymptomProcedure(slAlso check foi:
Random misfire only
at low RPM and
under load
Check fuel pressure (see page 1 1-145).. Low compressron.. Low quality fuel.
Random misfire only
du ring acceleration
Check fuel pressure (see page 11-145).Malfunction in the
VTEC system (see page
1' t-123).
Random misfire at
high RPM, under
load, or under
random conditions
Check fuel pressure (see page 11-145).Correct engine valve
clearances (see page 6-
91.
11-71
Page 302 of 1139

3.
4.
5.
6.
DTC Pl361: Camshaft Position (CMP) Sensor
B (TDC Sensor) Intermittent Interruption
DTC Pl362: Camshaft Position (CMP) Sensor
B (TDC Sensor) No Signal
1. Reset the ECM (see page 11-4).
2. Start the engine.
ls DTC P1361 and/or P1362 indicated?
YES Go to step 3.
NO- Intermittent failure. system is OK at this time.
Check for poor connections or loose terminals at
the CMP sensor B (TDC sensor) and at the ECM.I
Turn the ignition switch OFF.
Disconnectthe CMP sensor B (TDC sensor) 3P
connector.
Turn the ignition switch ON (ll).
Measure voltage between CMP sensor B (TDC
sensor) 3P connector terminal No. 3 and body
grouno.
CMP SENSOR B {TDC SENSOR) 3P CONNECTOR
{YEL/BLK}
Wire side ol temale terminals
ls there battety voltage?
YES Go to step 7.
NO-Repair open in the wire between the PGM-Fl
main relay 1 and the CMP sensor I (TDC sensor).I
IGP
123
7. l\4easure voltage between CMP sensor B {TDC
sensor) 3P connector terminal No. 1 and body
ground.
CMP S€NSOR 8 ITDC SENSOR) 3P CONNECTOR
Wlre s de ollemaleterminals
ls there about 5 V?
YES-Go to step 8.
NO-Go to step 10.
8. Measure voltage between Cl\ilP sensor B (TDC
sensor) 3P connector terminals No. 2 and No, 3.
CMP SENSON B llOC SENSOfi) 3P CONNECTOF
Wire s de olfema etefminals
ls there battery voltage?
YES-Go to step 9.
NO Repair open in the wire between the CMP
sensor B (TDC sensor) and G101.1
9. Substitute a known-good CMP sensor B (TDC
sensor) and recheck.
ls DTC P1361 and/or P1362 indicated?
YES Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
NO Replace the original CMPsensorB(TDC
sensor).1
(cont'd)
11-95
Page 306 of 1139

19. Disconnect each of the components or the
connectors below, one at a time, and check for
continuity between PGM-FI main relay 1 4P
connector terminal No. 1 and body ground.
. PGfvl-Fl main relay 2. ECM connector A (31P)
. Each injector 2P connector. ldle air control (lAC)valve 3P connector. Camshaft Position (CMP) sensor B (Top dead
center (TDC) sensor) 3P connector. Crankshaft position (CKP) sensor 3P connector
PGM-FI MAIN RELAY 14P CONNECTOR
ls thete continuity?
YES Go to step 20.
NO- Replace the component that made continuity
to body ground go away when disconnected. lf the
item is the ECM, update the ECM if it does not have
the latest software. or substitute a known-good
ECM, then recheck (see page 11-6). lf the symptom/
indication goes away with a known'good ECM,
replace the original ECM.
Also replace the No. 6 ECU (ECM) (15 A) fuse,
Disconnect the connectors of all these components.
. PGM-Fl main relay 2. ECM connector A (31P)
. lnjectors. ldle air control (lAC)valve
. Camshaft Position {CMP) sensor B (Top dead
center (TDC) sensor). Crankshaft position (CKP) sensor
20.
Wire side of female terminals
22.
21. Check for continuity between PGM-FI main relay 1
4P connector termlnal No. 1 and body ground.
PGM-FI MAIN RELAY 14P CONNECTOR
ls there continuity?
YES Repair short in the wire between the PGM-Fl
main relay 1 and each item. Also replace the No. 6
ECU {ECM) (15A) fuse.l
NO-Replace the PGM-Fl main relay 1. Also replace
the No 6 ECU {ECIM) (15A) f use. I
Inspectthe No. 17 FUEL PUI\4P (15A)fuse in the
under-dash f use/relay box.
ls the tuse OK?
YES Go to step 34.
NO Go to step 23.
Remove the blown No, 17 FU EL PUMP (15A) fuse
from the under-dash fuse/relay box.
Disconnect ECfvl connector E (31P).
(conr'd)
23.
24.
Wire side of female terminals
11-99