2000 HONDA CR-V Fuel and emissions

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
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.
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Misfire Detected in One Cylinder
Ipffi1] Thescantoot indicates Diagnostic Trouble Code (DTC) P0301: Cylinder 1 misfire detected.
lF03O2l 16".""n toot indicates Diagnostic Trouble Code (DTC) P0302; Cylinder 2 misfire detected.
I P0303 | fne scan tool indicates Diagnostic Trouble Code (DTC) P0303: Cylinder3 misfire detected.
lF0il04l 16" ""un tool indicates Diagnostic Trouble Code (DTC) PO3O4: Cylinder 4 misfire detected
Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor
which is attached to the crankshaft.
lf misiiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurrence. and DTC
P0301, P0302, P0303 and/or P0304 will be stored. Then, after the misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cycles. the MIL will come on, and DTc
P0301, P0302, P0303 and/or P0304 will be stored.
NOTE: lJ some of the DTcs listed below are stored at the same time as a misfire DTc, troubleshoot those DTcs first, then
troubleshoot the misfire DTC.
P0107, P0108, P'n2a, P1129t MAP sensor
Po'17 'l , P0112t Fuel suPP|Y system
P0441: EVAP insufficient Purge flow
P1336, P1337: CKF sensor
P1359, Pl361, P1362: TDC sensor
Pl381, P1382: CYP sensor
Possible Cause
. Fuel injector clogging, fuel leakage, air leakage
. Fuel injector circuit open or shorted
. Spark plug carbon deposits, fouling, malfunction
. lgnition wires open, leaking
. Distributor malfunction
. Compression low
. Valve clearance out of specification
(cont'd)
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Troubleshooting Procedures
Checking ths Diagnostic Trouble Code (DTC)
with an O8D ll Scan tool or Honda PGM Tsster
When the PCM senses an abnormality in the input or output systems, the El ('97 - 98) or E ('99 - O0) indicator light in thegauge ass€mbly will blink. When the 16P Data Link Connector (DLC) {located under the dash on the passenger's side) is
connected to the OBD ll Scan Tool or Honda PGM Tester as shown, the scan tool or tester will indicate the Diagnostic
Trouble Code (DTC) when the ignition switch is turned ON(ll).
HONDA PGM TESTER olOBD II SCAN TOOL
lf the E or E indicator light or the MIL has been reported on, or if a driveability problem is suspected, follow this proce-
dure:
1. Connect the OBD ll Scan Tool (conforming to SAE J1978) or Honda PGM Tester to the 16P DLC. (See the OBD ll ScanTool or Honda PGM Tester user's manual for specific instructions. lf you are using the Honda PGM Tester, make sureit is set to the SAE DTC Wpe).2. Turn the ignition switch ON (ll), and observe the DTC on the screen
3. Record allfuel and emission DTCS, A,,/T DTCS, and freeze data.
4. lf there is a fuel and emissions DTC, first check the fuel and emissions system as indicated by the DTC (except for DTCP0700). DTC P0700 means there is one or more Ay'T DTC, and no Droblems were detected in the fuel and emissionscircuit of the PCM.
5. Wire down the radio station presets.
6. Reset the memory with the PGM Tester o. by removing the BACK UP fuse in the under-hood fuse/relay box for morethan 10 seconds.
7. Drive the vehicle for several minutes at speeds over 30 mph (50 km/hr), and then recheck for DTCS. lf the A/T DTCreturns, 9o to the Symptom-to Component Chart on pages 14-60 and 14-61 for the '97 models, and pages 14-62 and14-63 for '98 - 00 models. lf the OTC does not return, there was an intermittent problem within the circuit. Make sureall pins and terminals in the circuit are tight, and then go to step 8.8. Reset the radio Dreset stations, and set the clock.
DATA LINK CONNECTOR {16PI
[ -=.r,
ili,i /i,
v,., i
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