1997 HONDA CR-V Control

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
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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.
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Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors iscutoffto improvefuel economyat
speeds over 970 rpm ('97 - 98 models), 920 rpm ('99 - 00 modelsl.
. Fuel cut-off action also takes place when engine speed exceeds 6,500 rpm ('97 - 98 models), 6900 rpm ('99 - 00
models), regardless of the position of the throttle valve, to protect the engine from over-rewing.
With Ay'T model. the PCM cuts the fuel at engine speeds over 5,000 rpm when the vehicle is not moving.*'
4,./C Comoressor Clutch Relav
When the ECM/PCM receives a demand for cooling from the air conditioning system, it delays the compressor from
being energized, and enriches the mixture to assure a smooth transition to the Ay'C mode.
Evaporative Emission (EVAP) Purge Control Solenoid Valve
When the engine coolant temperature is above 154"F (68'C), the ECM/PCM controls the EVAP purge control solenoid
valve which controls vacuum to the EVAP purge control canister,
Alternator Control
The system controls the voltage generated at the alternator in accordance with the electrical load and driving mode.
which reduces the engine load to improve the fuel economy.
PCM Fail-saf e/Back-up Functions
1. Fail-safe Function
When an abnormality occurs in a signal from a sensor, the ECM/PCM ignores that signal and assumes a pre-pre
grammed value for that sensor that allows the engine to continue to run.
2. Back-up Function
When an abnormality occurs in the ECM/PCM itself, the fuel injectors are controlled by a back-up circuit independent
of the system in order to permit minimal driving.
3. Self-diagnosis Function IMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the MIL and stores the DTC
in erasable memory. When the ignition is initially turned on {ll), the ECM/PCM supplies ground for the MIL for two
seconds to check the MIL bulb condition.
4. Two Trio Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S*1, fuel metering-related. idle control
system, ECT sensor and EVAP control system self-diagnostic functions. When an abnormality occurs, the ECM/PCM
stores it in its memory. When the same abnormality recurs after the ignition switch is turned OFF and ON (ll) again,
the ECM/PCM informs the driver by lighting the MlL. However, to ease troubleshooting, this function is cancelled
when you jump the service check connector, The MIL will then blink immediately when an abnormality occurs.
5. Two (or Three) Driving Cycle Detection Method {'97 model)
A "Driving Cycle" consists of starting the engine, beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions or EVAP control system malfunction is detected during two consecutive driving cycles.
or TWC deterioration is detected during three consecutive driving cycles, the ECM/PCM turns the MIL on. However, to
ease troubleshooting, this function is cancelled when you jump the service check connector. The MIL will then blink
immediately when an abnormality occurs.
*1: '97 - 98 models*2: '99 - 00 models
5.
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PGM-FI System
Powertrain Control Module {PCM} -'97 Model
NOTE: lf this symptom is intermiftent, check for a loose fuse No. 25 METER (7.5 A) in theunderdash f{rse/relay box, a poor connection at PCM terminal A18, or an intermittentopen in the GRN/ORN wire between the PCM (A18) and the gauge assembly.
PCM OON ECTOR A {32P}
Wire side of female terminals
PCM CONNECTOR A {32PI
Wire side ot temale terminals
11-42
The Malfunction lndicator LamD(MlL) nev6r comes on {even lortwo seconds) after ignition isturned on (lll, or it's on dimlyand flickers.
Turn the ignition switch ON {ll}.
- Rep.ir short or opon in thowire batween No. 25 METER(7.5 Alfuso and gauge a$€m-bty.- R6pl.c€ No. 25 METER 17.5 Alfus€.
ls the charging system light on?
Try to stan the engine.
Does the engine start?
Chock tor.n open in th6 wire3{PG1, PG2linesl:1. Turn the ignition switch ON (ll).2. Measure voltage betweenbody ground and PCM con-nector terminals A10 and A23individually.
Check for an op€n in the wir6 orbulb (MlL lin€l:1. Turn the ignition switch OFF.2. Connect the PCM connectorterminal A18 to body groundwith a iumper wire.3. Turn the ignition switch ON {ll).
n€peir open in tho wirelslhwoon PCM and Glol (loc!t.d
at thc tha.mo3tat houling thrthtd moro th.n 1.0 V.
ls thore l€ss than 1.0 V?
Substituto . known-good PCMand r€check. ll symptom/indica-tion goss away, rcplaca the origi-nal PCM.
- R6pai. open in th. wileibelwoon rcM lAl8l dnd g.ugea3rombly.- Roolac€ the MIL bulb.
ls the MIL on?
Substitut6 a known-good PCMand rocheck. ll 3ymptom/indica-tion goes away, replace the o.igi-n.l PCM.
PGl IBLKI
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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)
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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
Engine Control Module/Poweftrain Control Module (ECM/PCM) -'98 - 00 Models (cont'dl
NOTE:. When there is no Diagnostic Trouble Code IDTC) stored, the MIL will stay on iI the SCSservice connector is connected and the ignition switch is ON (ll).. lf this symptom is intermittent, check for:- An intermittent short in the wire between the ECM/PCM (A10) and the service checkconnoctor- An intermittent short in the wire between the ECM/PCM (At8l and the gaugeassemDty. See the OgD ll scan tool or Honda PGM Tester user's manuals for specific operatingrnstructions.
ECM/FCM CONNECTOF A {32P)
Wire side of femsle t6rminals
The Malfunction lndicator LamolMlll 3lays on or comes on aftertwo 3econds.
Check the Dirgnostic TroubloCod€ (DTCI:'1. Connect a scan tool or HondaPGM Tester.2. Turn the ignition switch ON (ll).3. Read the DTC with the scantool or Honda PGM Tester.
Go to troublGhooting procadura.(3€c prg€ l lS0l
check tho 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).
Ropair op.n ol Bhort in wirob.twe.n thc ECM/FCtrl (A21)
and D.i. Link Connoctor.Go to troublo3hootlng proc€-dur6. lt o pag. 11.6lrl
Does the MIL indicate any DTC?
Try to start the engine.
Sub3titute r known"good ECM/PCM .nd roch.ck. lt .ymptom/indic.tion gooa awsy, repl.cothe origin.l ECM/PCM.
Does the engine stan?
Check tor a 3hort in the wireISCS linel:1. Turn the ignition switch OFFand turn the ignition switchoN { ).2- Measure voltage betweenbody ground and the ECM/PCi, conneclor terminal A10.
Ropria ahort to body ground intho wi.c Mwe.n tho ECM/PCMlA10l and aarvic. check connsc-tor.
lTo page 1l-89)
11-88
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PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2S) lSensor 1) (cont'd)
tFO133 lhe scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated: Oxysen Sensor (Primarv 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 will be stored.
NOTE: lf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133. troubleshoot those DTCS first, then
troubleshoot DTC P0133.
Possible Cause
. Primary HO2S (Sensor 1) Deterioration
. Primary HO2S Heater (Sensor 1) Deterioration
. Exhaust system leakage
Troubleshooting Flowchart
- The MIL has b6€n reoorted on.- DTC P0133 is stored.
Problem Verilication:'1. Do the ECM/PCM Reset Procedure.2. Connect the scan tool.3. Start the engine. Hold theengine at 3,000 rpm with noload lin Park or neutrali untilthe radiator fan comes on.4. Connect the SCS service connector.5. Test-drive under the followingcondations,55 mph (89 km/h) steadyspeed- M in @ position (E position and Over Drive ON)*,(M/T in sth gear)- Until readiness code comes
Intermittent failure, system is OKat this time. Check tor poor con-nections or loose wires at C111(Primary HO2S, Sensor 1) and althe ECM/PCM.
Replace the Primary HO2S {Sen-sor 11.
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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
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