
PGM-FI System
System Description
CKP/TDC/CYP Sensor
MAP Sensor
IAT SensorTP SensorEGR Valve Lift Sensor*'Primary H02SSecondary HO2SVSSBARO SensorELD*'KS€Starter SignalALT FR SignalAir Conditioning SignalA/T Gear Position SignalBattery Voltage {lGN.1}Erake Switch SignalPSP Switch SignalFuel Tank Pressure Sensor*iVTEC Pressure Switch*5Clutch Switch Signal*6Countershaft Speed SensornBMainshaft Speed Sensorrs
-\
----t /
F;ilrr j"-----fi-tri-'r.;l
Fb"t."'i" d" c;;il
F,h"'c;;tr*".io";-l
@."r.l"sc;;ll
EaM/PcM B""k-p F"""till
r\
-:/
Fuel IniectorsPGM-Fl Main Belay {Fuel Pump)MILIAC Valve!y'C Compressor Clutch RelayRadiator Fan Relay*,Condenser Fan RelayALT*'lcMEVAP Purge Control Solenoid
Primary HO2S HeaterSecondary H02S HeaterEGR Control Solenoid Valve*rEGR valve*6EVAP Bypass Solenoid Valve*'EVAP Control Canister Vent Shut
VTEC Solenoid Valve*5DLCLock-up Control Solenoid Valve*aShift Control Solenoid Valve*3Linear Solenoid Valve*3
*1: Dl6Y5 engine*2: USA model*3: CW (D16Y5 ensine), D16Y8 engine and 81642 ensine*4: '96 D16Y8 engine lcoupe),'97 Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model),'97 D16Y8 engine {coupe: all models, sedan: KLmodel),'98-all models,'99'all models,'00-all models+5: D16Y5, D16Y8,816A2 engine*6: M/T (D16Y5 enginei*7: CVT 1D'l6Y5 engine)+8: A/T (D16Y7, D16Y8 engine)*9: '96 D16Y5 engine,'96 D16Y7 engine,'96 Dl6Y8 engine (sedan),'97 D16Y5 engine,'97 Dl6Y7 engine (coupe: KA, KC models, sedan:KA, KC, KL (LX) models, hatchback: all models),'97 D16Y8 engine (sedan: KA, KC modelsi
PGM-FI Sy3lem
The PGM-Fl system on this model is a sequential multipon fuel injection system.
Fuel iniector Timing and Duration
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold air flow rates.
The basic discharge duration, after being read out from the memory. is further modified by signals sent from various sen-
sors to obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve llAC Valve)
When the engine is cold. the A,/C compressor is on, the transmission is in gear, the brake pedal is depressed, the P/S load
is high, or the alternator is charging, the ECM/PCM controls current to the IAC Valve to maintain the correct idle speed.
lgnition Timing Control
. The ECM/PCM contains memories for basic ignition timing at various engine speeds and manifold air flow rates.
lgnition timing is also adjusted for engine coolant temperature.
. Aknockcontrol system was adopted which sets the ideal ignition timing for the octane rating ofthegasoline used.*3
Othgr Control Funqtions
1. Starting Control
When the engine is started, the ECM/PCM provides a rich mixture by increasing fuel injector duration.
2. Fuel Pump Control
. When the ignition switch is initially turned on, the ECM/PCM supplies ground to the PGM-Fl main relay that sup-plies current to the fuel pump for two seconds to pressurize the fuel system.. When the engine is running, the ECI\4PCM supplies ground to the PGM-FI majn relay that supplies current to the fuel
oumo.
. When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which
cuts current to the fuel pump.
11-104
INPUTS
ENGINE CONTROL MODULE (ECMY
POWERTRAIN CONTROL MODULE (PCM) OUTPUTS

Primary Heated Oxygen Sensor {Primary HO2SI (Sensor 1)
t('96 - 98 Models except Dl6Y5 engine with M/Tl
The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the ECM/PCM. In operation,
the ECM/PCM receives the sjgnals from the sensor and varies the duration during which fuel is injected To stabilize the
sensor,s output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in the exhaust manifold.
HO2S:
VOLTAGE {VI
The scan tool indicates Diagnostic Trouble Code (DTC) P0131; A low voltage
Oxygen Sensor (H02S) (Sensor 1) circuit.
R|cH-AIR- - LEANFUELRANO
problem in the Primary Heated
SENSOR
ztRcoNlA
The MIL has be€n teported on.DTC P0131 is siorcd.
Problom verificalion:1. Do the ECM/PCM Reset Pro'
cedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on,3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the Primary HO2S(Sensor 1) output voltage with
the scan tool during accelera-
tion using wide open throttle.
lntcrmift€nt failura, 3Y3tem is OKat this tims. Check for Poor con-nections or loo3e wi.o3 at C123(Primlry HO2S, 3sn3or 1) and
ECM/PCM,
(To page 1I-140)
{cont'd)
1 1-139

Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('96 - 9b Models except Dl6Y5 engine with M/Tl
PHO29IWHT}
The scan tool indicates Diagnostic Trouble Code (DTC) P0132: A high voltage problem in the Primary Heated
Oxygen Sensor (Primary H02S) (Sensor'l) circuit.
PRIMARY HO2S (Sonso. 'll 4P CONNECToR
tc123t
sG2IGRN/BLKI
Wire side ot female terminals
ECM/PCM CONNECTOR D I16PI
JUMPER WIRE
PHO2S (WHT}SG2 IGRN/BLKI
Wire side of tem6le terminals
Probl€m verification:1. Do the ECM/PCM Reset Pro-
cedure.2. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the PrimarY HO2S(Sensor 1) oLltPut voltage with
the scan tool during decelera'tion using completely closed
throttle.
Int.rmittont fiilur., system it OK
at thb timo. Chock for Poot con-
nections or loo3a wir63 at Cl23
lPrimarY HO2S, SensoJ 1l .nd
ECM/PCM.
Does the voltage stay at 1.0 V
or more?
Check for an open in the Primary
HO2S:1. Turn the ignition switch OFF.
2. Disconnect the Primary HO2S(Sensor 1) 4P connector'
3. Connect the PrimarY HO25
lSensor l) 4P connector termi-
nals No. 1 and No. 2 with a
4. Turn the ignition switch ON (ll).
5. Check the PrimarY H02S(Sensor 1i outPut voltage with
the scan tool.
lsthere 1.0 V or more?
Check for an open in the wiro
{PHO2S line):1. Turn the ignition switch OFF.
2. Connect EcM/PcM connector
terminals D7 and D11 with ajumper wrre,3. Turn the ignition switch ON lll)4. Check the PrimarY HO2S(Sensor 1) output voltage withthe scan tool,
Replir open in tho wirc b€twccnECM/PCM lo?) and Prim!.Y
HO2S lsonsor 1).ls there 1.0 V or more?
Substitute a known-good ECM/PCM and recheck. lf 3ymptom/indicetion goos awey, roplacethe oliginal ECM/PCM.
11-143

Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1l
The scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated
Oxygen Sensor {Primary H02S) (Sensor 1) circuit.
The scan tool indicates Diagnostic Trouble code (DTC) Pl163: A slow response problem in the Primary Heated
Oxygen Sensor (Primary HO2S) (Sensor 1)circuit
Description
By controlling the airlfuel ratio with a Primary Ho2S {Sensor 1) and a secondary HO2S {Sensor 2), the deterioration of the
primary HO2S (Sensor 1) can be evaluated by its feedback period. when the feedback period of the Ho2s exceeds a cer-
tain value during stable driving conditions, the sensor will be judged as deteriorated
when deterioration has been detected during two consecutive trips. the MIL comes on and DTC P0133 or P1163* will be stored'
NOTE: tf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133, troubleshoot those DTCS first' then
troubleshoot DTC P0133. lf DTC Pl 162, P1168 and/or P1169 are stored at the same time as DTC P1163, troubleshoot those
DTCS first, then recheck for DTC Pl163.
Possible Cause
o Primary HO2S (Sensor 'l) Deterioration
o Primary HO2S Heater (Sensor 1)Deterioration
. Exhaust system leakage
Troublsshooting Flowchart
tFol3al
I P1163
- The MIL has been reported on- DTC P0133 and/or Pl163* is
stored,
Problem Verilication:1. Do the ECM/PCM Reset Pro
cedure-2. Connect the scan tool
3. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
4. Connect the SCS service con-
nector.5. Test-drive u nder Iollowing
conditions.- 55 mph (88 km/h) steadyspeed- A/f in D position {M/T in
5th gear)
Until readiness code comes
lntermittent failure, 3Y3tem i3 OK
at thi3 time. Ch.ck lol Poor con-
ncctions or loosc wiros at C123
{C145)! lPrimary HO2S, Sensor 1l
and ECM/PCM.
Replace th6 Prim.ry HO2S (Sen'
sor 11.
*: P'l163 (D16Y5 engine with M/T)
11-145

PGM-FI System
Itil-"w Heated Oxygen Sensor (primary HO2S) (sensor 1l(Dl6Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) p1162: A malfunction in the primary Heated OxygenSensor (Primary HO2S) (Sensor 1) circutt.
Doscription
The Primary Heated orygen sensor (Primary Ho2s) {sensor 1) operates over a wide airlfuel range. The primary Ho2S(Sensor 1) is installed in the exhaust manifold.
SEI{SORELEMENT
SENSORTERMINALS
ECM CONNECTOR C (31PIPRIMARY HO2S(SENSOR 1)8PCONNECTOR {Clir5)
female terminalsof femaleterminals
NOTE: lf DTC Pl162 is stored at the same time as DTC Pl167, troubteshoot DTC p1162 first, then recheck for DTC p1167.
(To page 11-147)
- lh6 MIL hes b6on reDorted on.- DTCPl162 ir 3tored.
Problom v6rificationi1. Do the ECM Reset Procedure.2. Start the engine.3. Wait at least tlvo minutes.
Test drive tor several miles withthe transmission in 3rd gear. Holdthe engine speed at 1,500 rpm.
ls DTC P1162 indicatod?
Intermittent tailuro, systom is OKat this timo. Check tor poor con-nections or loose wires at C145(Plimr.y HO2S, Senso. t) andECM,
ls DTC P1162 indicated?
Chock for an open in the wire(lP+ lins):1. Turn the ignition switch OFF.2. Disconnect ECM connector C{31P) from the ECM.3. Disconnect the 8P connectorfrom the Primary HO2S {Sen-sor 1).4. Check for continuity betweenthe Primary HO2S (Sensor 1)8P connector terminal No. 7and ECM connector terminalc23.
Repair open in the wire betwaonECM (C231 end Prim.ry HO2Slsen3or l).
Inspect lor poor terminal to termi-nal contact at the Primary HO2Slsensor 'l I connoctor and ECM.It terminal contect is OK, roplacelh6 Primrry HO2S {Sensor 1}.
11-146

PGM-FI System
l:in1.".fy Heated Oxygen Sensor (primary HO2SI (sensor 1l(D16Y5 engine with M/D (cont'd)
The scan toor indicates Diagnosti" -Tl:y|* code (DTC) pl164: A range/performance probrem in the primaryHeated Oxygen Sensor (primary HO2S) (Sensor 1)circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) p1165: AHeated Oxygen Sensor (primary HO2S) (sensor 1) circuit.
range/performance problem the pnmarv
The MIL has beon reponed on.DTC P1164 is stored.
Problem Verilication:1. Do the ECM Beset Procedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiatorfan comes on.3. Connect the SCS service con-nector.4. Test-drive in 4th gear. Startingat 1,600 rpm, accelerate usingwide open throttle for at least 5seconds. Then decelerate tor atleast 5 seconds with the throttle completely closed.
Intgrmittent failure, syrtem b OKat this time. Check tor Door con-noctions or loose wires at C1a5(Primary HO2S. Senso.
andECM.
ls DTC Pl164 indicatedT
- The MIL has been reoorted on.- DTC P1165 is stored.
Intermittent l.iluro, system b OKat lhis time. Ch€ck tor poor con-noctions or loose wir6 at Ci45(Prioary HO2S, Sen3or 1l .ndECM.
ls DTC P1165 indicated?
Replace the P.imary HO2S (S6n-sor 11.
Problem Vo.ification:1. Do the ECM Reset Procedlre.2. Start the engine. Hotd theengine at 3,000 rpm with noload (transmission in neutral)until the radiator fan comes
3. Connect the SCS service con,nector.4. Test-drive u nder followingconditions.- 55 mph steady speedTransmission in 5th gearUntil readiness code comes
1 1-150

PGM-FI System
Barometric Pressure (BAROI Sensor
The scan tool indicates Diagnostic Trouble code (DTC) Pi106: A range/performance problem in the BaromerrrcPressure (BARO) Sensor circuit.
The scan tool indicates Diagnostic Trouble code (DTc) P1107: A low voltage probtem in the Baro sensor circurr.
The scan tool indicates Diagnostic Troubre code {DTC) p1108: A high vortage probrem in the Baro sensorcircuit.
fF1lot
tPlloal
The MIL ha3 been r€Dortsd on.DTC Pl106 is stored.
Problem verification:1. Do the ECM/PCM reset pro-cedure,2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on, thenlet it idle.3. Connect the SCS service connector.4. Test drive with the A/T in Eposition, M/T in 4th gear.5. Accelerate for five secondsusing wide open throttle.
Intormittont tailure, system is OKat this time.ls DTC P1106 indicated?
Substitut€ e known-good ECM/PCM and recheck. ll symptom/indication goes .way, .oplsce theo.iginal ECM/PCM.
The MIL has been .oported on.DTC P'l107 o. Pl108 is stored.
P.oblem veritication:1. Do the ECM/PClvl Reset pro
cedure,2. Turn the ignition switch ON (ll).
Intormittent frilure, syitem i3 OKat this time.ls DTC P1 107 or Pl108 indicated?
Substitute a known-good ECM/PCM and rechock. It symptom/indication goes away, .6placethe original ECM/PCM.
11-178

1.After the engine starts, the lAc valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is tow, the IAC valve is opened to obtain the proper fast idle speed. The amount of
bypassed air is thus controlled in relation to the engine coolant temperature'
IOLE SPEED
lrpml
176
80
ENGI ECOOLANI TEMPERATURE
t" Fl
toc)
ll
't.Whentheid|espeedisoutofspeciiicationandthescantoo|doesnotindicateDiagnosticTroub|ecode(DTc)P0505
or P1508. check the following items:
. Adiust the idle speed {see page 11-220}
. Starter switch signal (see page 11-202)
. Air conditioning signal (see page l1-204)
. ALT FR signal (see Page 11-2081
' Brake switch signal (see page 11-210)
. PSP switch signal (excapt Canada model) (see page 11-212)
. A,/T gear position signal {see section 14, Dl6Y5 engine (CVT):
page 11-216). Clutch switch signal (D16Y5 engine with M/T) (see page 11-218)
. Hoses and connections
' IAC valve and its mounting O-rings
lf the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 11-220)
|ftheid|espeedsti||cannotbeadjustedtospecification(andthescantoo|doesnotindicateDTcP0505orP]50S)
after IAC valve replacement. substitute a known-good ECM/PCM and recheck. lf symptom goes away, replace the
original ECM/PCM.