PGM-FI System
System Description
INPUTS
CKP/TDC/CYP Sensor
CKF Sensor
MAP Sensor
ECT Sensor
IAT Sensor
TP Sensor
Primary HO2S
Secondary H02S
vss
KS*5
BARO Sensor
ELD*6
Starter Signal
ALT FR Signal
Air Conditioning Signal
Ay'T Gear Position Signal*1
Baftery Voltage (lGN.1)
Brake Switch Signal
PSP Switch Signal
Fuel Tank Pressuae Sensor*4. *5
Countershaft Speed Sensor*1
Mainshaft Speed Sensor*r
OVER-DRIVE Switch Signal*s
ENGINE CONTROL MODULE (ECM)/
POWERTRAIN CONTROL MODULE (PCM) OUTPUTS
|iuel 1"j""- Th,rhg ""d Drrafr";-l
Et*-.nt"tdt"cont.orl
to,r*,c;;trffi;]
l.----.---:. .Lrgnrnon |lmrng Lonrror I
Ecir/PcM B*k',p Fr""il]
m;"t-ll-r*'io*l
Fuel Injectors
PGM-Fl Main Relay (Fuel Pump)
MIL
IAC Valve
Ay'C Compressor Clutch Relay
Radiator Fan Relay
Condenser Fan Relay
ALT
tcM
EVAP Purge Control Solenoid
Valve
Primary HO2S Heater
Secondary H02S HeaterEVAP Bypass Solenoid Valve*a *5
EVAP Control Canister Vent Shut
DLC
Lock-up Control Solenoid Valve*l
Shift Control Solenoid Valve*1
Ay'T Clutch Pressure Control
Solenoid Valve*1
D4 Indicator Light'1 *3, *a
D Indicator Light,l *5
OVER-DRIVE OFF Indicator
Lighl*t *:
*1: A/T {3:'97 model'2: M/f +4:'98 model*5: '99 - 00 models"6: USA
PGM-Fl System
The PGM-Fl system on this model is a sequential multiport fuel injection system.
Fuel iniecior Timing and Duration
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold pressure. The
basic discharge duration, after being read out from the memory, is further modified by signals sent from various sensors
to obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve (lAC Valve)
When the engine is cold, the Ay'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
o The ECM/PCM contains memories for basic ionition timing at various engine speeds and manifold air flow rates.
lgnition timing is also adjusted for engine coolant temperature.
. A knock control system was adopted which sets the ideal ig nition timing for the octane rating of the gasoline used.*s
Other Control Funstions
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 (ll). the ECMiPCM suppli€s ground to the PGM-FI main relay that
supplies current to the fuel pump for two seconds to pressurize the fuel system.
. When the engine is running, the ECM/PCM supplies ground to the PGM-FI main 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.
1 1-80
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NOTE:. When there is no Diagnostic Trouble Code (DTC) stored, the MIL will stay on if the SCSservice connector is connected and the ignition switch is on.. lf this svmotom is intermittent, check for:- A loose Fl E/M (15 Aifuse in the underdash tuse/relay box- A loose No. 13 FUEL PUMP {15 A) fuse in the under-dash fuse/relay box- An intermittent short in the wire between the PCM (C7) and the service check con-
- An intermittent short in the wire between the PCM (A18) and the gauge assembly- An intermittent shon in the wire betlveen the PCM (D4) and the MAP sensor- An intermiftent short in the wire between the PCM {D10) and the TP sensor.PGM-Fl main relay.'See the OBD ll scan tool or Honda PGM Tester user's manuals lor specilic operatinginstructions,
NOTE: An open or short in the wire between the PCM (C8) and the DLC will keep thescan tool or Honda PGM Tester lrom communicating with the PCM. You should ioterpretthis as no DTCS are indicated.
PCM CONNECTORc l3lPl scs .BRNI
lTo page 11 84)Wire sid6 of f€male terminalg
(cont'dl
11-83
The Malfunciion lndicator Lamo{MlL) stavs on o. comes on afteltwo seconds,
Check the Oiegnosiic TroubleCode (DTC):
1. Connect an OBD ll scan toolor Honda PGM Tester.2. Turn the ignition switch ON 1lli.3. Read the DTC with the scantool or Honda PGII Tester.
Go to troubleshooting procedures(s€€ page 11501.Are any DTCIs) indicated?
Ch6ck lh6 DTC by MIL indication:1. Turn the ignition switch OFF.2. Connect the SCS service con-nector to the service checkconnector.3. Turn the ignition switch ON (ll).
- Repair opon or short in wi.6between the PCM (C8) andData Link Connector.- Go to troubloshooting proce-
dur€s {3ee page 11-601.
Does the MIL indicate any DTc?
Try to start the engine.
Does the engine start?
Check tor a short in the wire{SCS line):1. Turn the ignition switch OFFand turn the ignition switchoN flt).2. Measure voltage between thePCM connector terminal C7and body ground.
Repair short to body ground inthe wire between PCM lCTl andservice check connector.ls there approx. 5 V?
(To page 1'l-84)
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Powertrain Control Module (PCM) -'97 Model (cont'dl
(From page 11 83)
Check for a short in the wire (MlL
line):1. Turn the ignition switch OFF.2. Disconnect the PCM connectorA {32P).3. Turn the ignition switch ON (ll).
Repair short to body ground inthe wire between the PCM {418}and MlL.ls the MIL ON?
Substitute a known-good PCMand recheck. lf symptom/indica-tion goes away. replace the origi-nal PCM.
Inspect Fl E/M (15 A) fuse in theundeFhood fuse/relay box.
- Reoair shod in the wirebetween Fl E/M {15 A} fuseand PGM-FI main relav.- Replace FIE/M 115 A)fuse.
Inspect No. 13 FUEL PUMP (15 Aifuse in the underdash fuse/relay
- Repair short in lh€ wirebolween No. 13 FUEL PUMP
115 A) Iuse and PGM-FI main
- Replace No. 13 FUEL PUMP
115 A) fuse.
Check loJ a short in a sensor:1. Turn the ignit;on switch ON (ll).
2. Disconnect the 3P connectorof each sensor one at time:. MAP sensor
(To page 11-85)
11-84
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(From page 11-84)
Reolace the Sensor that causedthe lighl lo go out.Does the MIL go off.,
Check for a short in the wires
lvCC linesl:1. Turn the ignition switch oFF.2. Disconnect the PCM connector D (16P).
3. Check for continuity betweenbody ground and PCM connector terminals D4 and Dl0 individually.
Repair shorl lo body ground
in the wile between the PCM
{D4} and the MAP sensor.Repair short to body ground inth€ wire between the PCMlol0l and the TP sensor.
Check tor an open in the wires
llGP line3l:1. Disconnect the fuel injectorconnectors and IAC valve con
2. Turn the ignition switch ON (lli.
3. [,4easure voltage betweenbody ground and PCM con'nector terminals A'11 and A24individually.- Repair open in the wire(slboiween the PCM 1A11, A24)and the PGM-Fl main relav.- Ch€ck lor poor connectionsor loose wires at ihe PGM-FImain relay.- Tesi lhe PGM-FI main relav
{see p.g6 1l-1871.Check for an open in the wires
{LG linesl:1. Turn the ignition switch OFF.2, Reconnect all sensor connec-tors,3. Reconnect the PCM connectorD (16P).
4. Turn the ignition switch ON (ll).
5, M easu re voltage betweenbody ground and PCM connector terminals Ag a^d 422individually.
R6pair open in the wire{slbetween the PCM {A9. A22l andG101 {located at the thetmostathousing) that had more than 1.0 V.
ls there less than 1.0 V?
Substituto a known-good PCMand rech€ck. It symptom/indica-tion goos away, replace the origi-nal PCM.
PCM CONNECTOR D (16PI
VCCl NEL/RED}
Wire side of female terminals
PCM CONNECTOR A (32PI
Wire side of lemale terminals
1 1-85
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PGM-FI System
Tho Maltunction Indicator Lamo(MlL) n6Yor como3 on leven lortwo laconds) rft6r tho ignhion isturnod ON {lll.
Turn th6 ignition switch ON (ll).
- Repair lhort or opcn in thowire between the No. 25METER 17.5 Al fu3e snd thegauge assembly.- Repl.co the No. 25 METER17.5 Al fus€.
ls the low oil pressure light on?
Try to start the engine.
Chock for an opsn in th€ wiro orbulb {MlL line,:1. Turn the ignition switch OFF.2. Connect the ECM/PCM con-nector terminal A18 to bodyground with a iumper wire.3. Turn the ignition switch ON (ll).
Rep.ir open in the wi.osbotween the ECM/FCM lA18land the gaugo rasombly.Roplece the MIL bulb.
ls th6 MIL on?
Substitute a known-good ECM/PCM and rochock. lf rymptom/indication goes eway, replacetho o gind ECM/PCM.
Turn the ignition switch OFF.Inspect the Fl E/M 115 A) tusein the undeFhood fuse/relaybox.
- Repair short in the wirebetween lhe Fl E/M (15 AlfusG and the PGM-Fl m.in.slay.- Roplsce th€ Fl E/M (15 Alfu3€.
Inspect the No. 13 FUEL PUMP(15 A) fuse in the under-dashfuse/relay box.
- Repair short in th6 wirebetween tho No. 13 FUELPUMP 115 A) luse and thePGM-FI main .elay.- ReDlace tho No. 13 FUELPUMP 115 Al tuse.
Engine Gontrol Module/Powertrain Control Module (ECM/PCM) -'98 - 00 Models
NOTE:. lf this symptom is intermittent, check tor:- A loose Fl E/M {15 A) fuse in the under-hood fuse/relay box- A loose No. 25 METER {7.5 A) fuse in the under-dash fuse/relay box- A loose No. 13 FUEL PUMP (15 Alfuse in the underdash fuse/rolay box- An intermiftent short in the wire between the ECM/PCM (A18) and the gauge assem-
- An int€rmiftent short in the wire between the ECM/PCM (C19) and the MAP sensor- An intermiftent short in the wire between rhe ECM/PCM (C28), the TP sensor, theEGR valve lift sensor and/or {uel tank Dressure sensor- A laulty PGM-FI main relay
ECM/PCM CONNECTOR A (32P}
Wire side of female terminals
(To page 11-871
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PGM-FI System
Fuel Supply System
[POliil The"""ntool indicates Diagnostic Troubte Code (DTC) p0'171:Thefuet system istoo lean.
[Fo17ZJ rh""""ntool indicates Diagnostic Troubte code {DTc) p0172:Thefuel svstem istoorich.
Description
By monitoring the Long Term Fuel rrim, long term malfunctions in the fuel system will be detected.lf a malfunction has been detected during two consecutive trips, the MIL will come on and DTc p0171 and/or pol72 will bestored.
NOTE: lf someof the DTCS listed below are stored atthesametimeas DTC P017'l and/or p0172, troubleshoot those DTcsfirst, then troubleshoot DTC P0171 and/or PO1i2.
P0107, P0108, P1128, P'1129: MAP Sensor
P0135: Primary HO2S (Sensor 1)Heater
P0137, P0138: Secondary HO2S {Sensor 2)P0141: Secondary H02S (Sensor 2) Heater
P0441*r: EVAP System lnsufficient Purge FtowP1456*,, P'l457 *?i EVAP System Insufficient purge Ftow
Possible Cause
DTC P0171
too lean
*1: '97 model*2: '98 - 00 models
Fuel Pump insufficient flow/pressure
Fuel Feed Line clogged. leaking
Fuel Pressure Regulator stuck openFuel Filter clogged
Fuel Injector clogged, air leakage
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closedFuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary H02S (Sensor 1) deteriorated
EVAP Purge Control Solenoid Valve leaking, stuck openedValve Clearance
DTC P0172
flch
11-124
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PGM-FI System
Random Misfire
lF()gool", tftod-' and some or lpiogol throughTo3oti
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*,, P1300*1 and some of po30t - pO3O4; Randommisfire.
Descriotion
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (cKF) sensorwhich is attached to the crankshaft.lfmisfiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurrence, and DTcP0300*' , P1300*1 and some of DTCs P03ol through P0304 will be stored. Then, after misfire has ceased, the MtL will comeon,
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTcand some of DTCS p0301 through p0304 wi
be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTc, troubleshoot those DTcs first. thentroubleshoot the misfire DTC.
P0106, P]128, P1'129; MAp sensorP0171. P0172; Fuet metering
P0505: ldle Control Svstem
P1336, P1337; CKF sensor
P1361, P1362: TDC sensor
Pl381. Pl382: CYP sensor
P1508: IAC valve *1:,97 model*2: '98 - 00 models
Possiblo Caus€
. Fuel pump insufficient fuel pressure, amountofflow. Fuel line clogging. blockage, leakage. Fuel filter clogginga Fuel pressure regulator stuck open. Distributormalfunction
. lgnition coil wire open, leakage. lgnition control module malfunction. Valves carbon deposita Compression lowa Fuel does not meet Owner's Manual spec., lack offuel
Troubleshooting
By test-driving, determine the conditions during which misfire occurs. Depending on these conditions, test in the orderdescribed in the table below.
Possible cause
[ ;;;;- -....
Crankshaft
speed fluctuation
sensor
Fuel
pressureDistributor and
lgnition wirestcMValve
Clearance
Conditionsection 611-178section 23section 23section 6
Only low rpm and load,6)o
Only acceleratingooo
Only high rpm and loado@,a'@
Not specificationG\o@o@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owner's manual spec, lack of fuel, carbondeposits on spark plu9, etc.
11-126
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Fuel Supply System
Fuel Lines
Check fuel system lines, hoses, fuel filter, and other components for damage, leaks or det6rioration, and r€place it neces-
sary.
'97 model:33 N.m(3.4 kg(.m, 2s lbf.ftl
27 N.m12.8 kg{.m, 21 lbf.ft)
'98 model:
(cont'd)
11-171
27 N.rn(2.8 kgl.m, 21 lbf.ft)
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