1997 HONDA CR-V engine speed

ldle Control System
Fast ldle Thermo Valve lA/T)
Description
To prevent erratic running when the engine is warming
up, it is necessary to raise the idle speed. The fast idle
thermo valve is controlled by a thermowax plunger.
When the engine is cold, the engine coolant surround-
ing the thermowax contracts the plunger, allowing addi-
tional air to be bvDassed into the intake manifold so that
the engine idles faster. When the engine reaches operat-
ing temperature. the valve closes, reducing the amount
of air bypassing into the intake manifold.
IDLEADJUSTING
IDLETHERMOVALVE
AIR BYPASS VALVE
11-168
Inspgction
NOTE: The fast idle thermo valve is factory adjusted; it
should not be disassembled.
1. Remove the intake air duct from the throttle body.
2. Start the engine,
3. Put your finger over the lower port in throttle body,
and make sure that there is air flow with the engine
cold (engine coolant temperature below 86"F, 30'C).
lf there is no air flow, replace the fast idle thermo
valve and retest,
O-RINGSReplace.
11.0 kgfl.m, 7.2 lbl.ftl
Start the engine. Hold the engine at 3,000 rpm with no
load (in Park or neutral) until the radiator fan comes
on, then let it idle.
Check that the valve is completely closed. lf the valve
is leaking, the idle speed will drop when you cover the
lower pon. Check the engine coolant level and for air
in the engine cooling system {see section 10). lf the
cooling system is OK, replace the fast idle thermo
valve and recheck.
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ldle Speed Setting
Inspoction/Adiustmont
37 modsl:
NOTE:
. Before setting the idle speed, check the following
items:- The MIL has not been reportsd on.- lgnition timing- Spark plugs
- Air cleaner- PCV system
. lcanada) Pull the parking brake lever up. Stan the
engine, then check that the headlights are off.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
Connect a tachometer or a Honda PGM Tester.
Disconnect the 2P connector from the ldle Air Con-
trol (lAC) valve.
IAC VALVE
lf the engine stalls, restart the engine with the accel-
erator pedal slightly depr6ss6d, Stabilize the rpm at
1,000, then slowly release the pedal until the engine
idles.
Check idling in no-load conditions: hsadlights,
blower fan, rear d€fogger, radiator fan, and air con-
ditioner are not operating.
ldle spood should b.:
{80 t 50 rpm {in Park or noutr.ll
IDLE
7.
Adjust the idle sp6ed,
idle adjusting screw.
if necessary, by turning the
Turn the ignition switch OFF.
Reconnect the 2P connector to the IAC valve, then
remove the BACK UP (RAD|Ol (7.5 Al fuse in the
under-hood fuse/rslav box for 10 seconds to reset
the PCM.
Restart and let the engine idle with no-load condi-
tions for one minute, then check the idle speed.
NOTE: (Canadal Pullthe parking brake lever up. Stan
the engine, then check that the headlights are off.
ldlo Ep€ed rhould be:
75O t 50 rpm (in P.rk or noutr.ll
Let the engine idl6 for one minute with the head-
lights (Low) ON, and check th€ idl€ speed.
ldle lpcod 3hould bo:
750 t 50 ]pm (in Park or nautlal)
Turn the headlights off. Let th€ engine idle for one
minute with the headlights (Low) ON, heater fan
switch at Hl and air conditioner on. then check the idle
sDeeo.
ldl. specd should b6:
7d) 1 50 rpm {in Park or nautral}
lf the idle speed is not within specification, see the
symptom chart on page 11-64. (cont'd)
1 1-169
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ldle Control System
ldle Speed Setting (cont'd)
38 - 0O mod6l3:
NOTE: Before setting the idle speed, check the follow-
ing items:- The MIL has not been reported on.- lgnition timing- Spark plugs
- Air cleaner- PCV system
1. Start the engine. Hold the engine at 3.000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
Connect a tachometer.
Disconnect the IAC valve 2P connector and the EVAP
purge control solenoid valve 2P connector.
CONTROLSOLENOID VALVE
SOLENOID VALVE
lf the engine stalls, restart the engine with the accel-
erato. pedal slightly depressed. Stabilize the rpm at
1,000, then slowly release the pedal until the engine
idles.
Che€k the idle in no-load conditions: headlights, blow-
er fan, rear defogger, radiator fan, and air conditioner
are not operating,
ldle speed should bo:
480 t 50 rpm {in PErk or noutrall
11-170
lf necessary, adjust the idle speed, by turning the
idle adjusting screw.
After adjusting the idle speed, recheck the ignition
timing (see section 4). lf it is out of spec, go back to
steo 4.tDt.E
6. Turn the ignition switch OFF.
7. Reconnect the 2P connectors to the IAC valve and
the EVAP purge control solenoid valve, then do the
ECM/PCM reset procedure.
8. Restart and idle the engine with no-load conditions
for one minute, then check the idle speed.
ldle speod should be:,98 model:
750 t 50 rpm tin Park or neutral)'9!l - 00 modsls:
730 i 50 lpm lin Psrk or neutral)
NOTE: lf the idle speed increases to 780 t 50 rpm(770 1 50 rpml*, this means the EVAP system is
purging the canister. To stop the purging temporari-
ly, raise the engine speed above 1,000 rpm with the
accelerator pedal, then slowly release the pedal.*: '99 - 00 models
9. Let the engine idle for one minute with the head-
lights (Low) ON, and check the idle speed.
ldle speed should be:
38 mod6l:
750 f 50 rpm (in Palk or neutrall'99 - 00 modols:
730 t 50 rpm (in Palk or neutral)
10. Turn the headlights off. Let the engine idle for one
minute with the heater fan switch at Hl and air con-
ditioner on, then check the idle speed.
ldls spqed should be:'98 model:
780 t 50 rpm (in Park or neutrall'99 - 00 mod€ls:
7701 50 rpm lin Park or neutral)
lf the idle speed is not within specification. see the
Symptom Chart on page 11-64.
ADJUSTING
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Emission Control System
System Description
The emission control system includes, a Three Way
Catalytic Converter {TWC), Positive Crankcase Ventilation
(PCV) svstem and Evaporative Emission (€VAP) Control
system. The emission control system is designed to meet
federal and state emission standards.
Tailpipe Emission
Inspsction
!@ Do not smoke during this procsdura. Keep
any open tlame away from your work area.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle,
Connect a tachometer.
Check and, if necessary, adjust the idle speed, (see
page 11-169, 170).
Warm up and calibrate the CO meter according to the
meter manufacturer's instructions.
Check idle CO with the headlights, heater blower, rear
window defogger, cooling fan, and air conditioner off.
(Canada) Pull the parking brake lever up. Start the
engine, then check that the headlights are off.
CO meter should indicate 0.1% maximum.
4.
Three Way Catalytic Converter (TWCI
DsscriDtion
Three Way Catalytic Convertsr lTwcl:
The Three wav Catalvtic Converter (TWC) is used to
convert hydrocarbons (HC), carbon monoxide (CO), and
oxides of nitrogen (NOx) in the exhaust gas to carbon
dioxide (COr), dinitrogen (Nr) and water vapor,
{cont'd)
1 1-199
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Emission Control System
Three Way Catalytic Converter {TWCI (cont'd}
1P0420 Thescantool indicates Diagnostic Trouble Code (DTC) P0420: Catalyst system efficiency belowthreshold.
DescriDtion
This system evaluates the catalyst's capacity by means of the HO2S (Primary and Secondary) output during stable driving
conditions. lf deterioration has been detected during three consecutive driving cycles, the MIL comes on and DTC P0420 will
be stored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0420, troubleshoot those DTCS first. then
troubleshoot DTC P0420.
P0137, P0138: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) Heater
Possible Cause
. IWC Deterioration
. Exhaust system leakage
Troubleshooting Flowchart
- The MIL has been reDoried on.- DTC P0420 is stored.
Problem verification:1. Do the ECM/PCM Reset Procedure,2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutrali untilthe radiator fan comes on.3. Connect the SCS service connector.4. Test-drive 40 - 55 mph (64 - 88km/h) for approx. lwo minutes.Then decelerate for at least 3seconds with the throftle completely closed. Then reducethe vehicle speed to 35 mph
156 km/h), and try to hold ituntil the readiness code
Intermittent tailure. system is OKat this time.ls DTC P0420 indicated?
Check the TWC (see section 9).lI nocessary, replace the TwC.
11-200
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'97 model:
The scan tool indicates Diagnostic Trouble Code (DTC) P0441: Evaporative Emission (EVAP) control system
insufficient purge flow.
Description
By monitoring the purge line vacuum with the MAP sensor, the PCM can detect insufficient EVAP control system purge
flow.
Possiblo Cause
. EVAP Purge Control Solenoid Valve
. EVAP Purge Control Solenoid Valve Circuit
. EVAP Control Canister
. Vacuum Lines
. PCM
Troubleshooting Flowchart
EVAP PURGE CONTROL
SO1TNOID VALVE 2P
CoNNECTOR (C108)
(v)
YL
Wire side of female
termrnals
(cont'd)
11-205
Th€ MIL has b€en reooited on.DTC P0441 is .tored.
Problem verificationl1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neut.al) untilthe radiator fan comes on.2. Do the PCM Reset Procedure.3. Connect the SCS service con-nector,4. Test drive under following con'ditions on the road.- without any electrical load- Transmission in @ or @position- Engine speed between1 ,2OO - 2,4OO rpfi.- Decelerate from 50 mph (80
km/h)to 15 mph (24 km/h)Intermittent trilure, sydern is OKat this time. Check for Door con-nections or loose wir€3 at C108
IEVAP purge control solonoidvalvol .nd at the PCM.
ls DTC P0441 indicated?
Check tor an open in the wire (lcl
linel:1. Turn the ignition switch OFF.2. Disconnect the EVAP purge
control solenoid valve 2P con-nector.3. Turn the ignition switch ON (ll).
4. Measure voltage between bodyground and the EVAP purge
control solenoid valve 2P con-nector terminal No. '1,
R€pafu open in thc wir6 b€tw€enthG EVAP purge control solenoidvalve and the No. 15 ALTEBNA-TOR SP SENSOR (7.5 A)fuse.
ls there batlery voltage?
(To page 11'206)
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Description
General Operation
The Automatic transmission is a 3-element torque converter and triple-shaft electronically controlled unit which provides 4
speeds forward and 1 reverse speed The unit is positioned in line with the engine'
There are two tvoes of automatic transmission on CR-V; the four-wheel drive (4WD) model ('97 - 00)' and the front-wheel
drive (2WD) model ('98 - 00).
Toroue Converter, G€ars, and Clutches
The torque converter consists of a pump. turbine. and stator assembly in a single unit. The torque converter is connected to
the engine crankshatt. These parts turn together as a unit as the engine turns. Around the outside of the torque converter is
a ring gear which meshes with the starter pinion when the engine is started. The torque converter assembly serves as a fly-
wheel while transmitting power to the transmission mainshaft.
The transmission has three parallel shafts: the mainshaft. the countershaft, and the sub-shaft. The mainshaft is in line with
the engine crankshaft. The mainshaft includes the 1st, 2nd. and 4th clutches, and gears lor 3rd,2nd,4th. reverse and 1st
(3rd gear is integral with the mainshaft, while reverse gear is integral with the 4th gear). The countershaft includes the 3rd
clutch and gears for 3rd,2nd, 4th, reverse, 1st, and park. Reverse and 4th gears can be locked to the countershaft at its cen-
ter, providing 4th gear or reverse, depending on which way the selector is moved. The sub-shaft includes the lst-hold
clutch and gears for lst and 4th.
The gears on the mainshaft are in constant mesh with those on the countershaft and sub-shaft. When certain combinations
of gears are engaged by the ctutches, power is transmitted from the mainshaft to the countershaft to provide E, D!, tr, tr,
and E position ('97 - 98 models). and E. E, E, and E position ('99 - 00 models)'
Electlonic Control
The electronic controt system consists of the Powenrain Control Module (PCM), sensors, a linear solenoid, and four
solenoid valves. Shifting and lock-up are electronically controlled for comfortable driving under all conditions. The PCM is
located below the dashboard, under the kick panel on the passenger's side.
Hydraulic Control
The valve bodies include the main valve body, the secondary valve body, the regulator valve body, the servo body, and
the lock up valve body. They are bolted to the torque converter housing. The main valve body contains the manual valve,
the 1-2 shift valve, the 2nd orifice control valve. the CPB {Clutch Pressure Back-up) valve, the modulator valve, the servo
control valve. the relief valve, and ATF pump gears. The secondary valve body contains the 2-3 shift valve, the 3-4 shift
valve, the 3,4 orifice control valve. the 4th exhaust valve and the CPC (Clutch Pressure Control) valve. The regulator valve
bodv contains the pressure regulator valve, the torque converter check valve, the cooler relief valve, and the lock-up con-
trol valve. The servo body contains the servo valve which is integrated with the reverse shift tork, and the accumulators
The lock-up valve body contains the lock-up shift valve and the lock-up timing valve. The linear solenoid and the shift con-
trol solenoid valve Ay'B are bolted to the outside of the transmission housing, and the lock-up control solenoid valve Ay'B is
bolted to the outside of the torque converter housing. Fluid trom the regulator passes through the manual valve to the
various control valves. The clutches receive fluid from their respective feed pipes or internal hydraulic circuit
ShiftControl Mechanism
input from various sensors located throughout the vehicle determines which shift control solenoid valve the PCM will acti-
vate. Activating a shift control solenoid valve changes modulator pressure, causing a shift valve to move. This pressurizes
a line to one of the clutches. engaging that clutch and its corresponding gear. The shift control solenoid valves A and B are
controlled by the PCM.
Lock-up Mechanism
tn E! position (,97 - 98 modets) and in E position ('99 - O0 models), in 3rd and 4th, and in Del position in 3rd ('97 - 98
models) and in El position with Over,Drive (O/D) is OFF (by pressing rhe O/D switchl in 3rd ('99 - 00 models), pressurized
fluid is drained from the back of the torque converter through a fluid passage, causing the lock-up piston to be held
against the torque converter cover, As this takes place, the mainshaft rotates at the same speed as the engine crankshaft.
Together with hydraulic control, the PcM optimizes the timing of the lock-up mechanism The lock-up valves control the
range of lock-up according to lock-up control solenoid valves A and B, and the linear solenoid. When lock-up control
solenoid valves A and B activate, the modulator pressure changes. The lock-up control solenoid valves A and B and the
linear solenoid are controlled by the PCM.
{cont'd)
14-3
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Description
General Operation (cont'dl
Gsar Selection'97 - 98 Models
The shift lever has seven positions; El PARK, ts REVERSE, N NEUTRAL, Ell 1st through 4th ranges, lpq 1st th.ough 3rdranges, P 2nd gear, and [ 1st gear
'99 - 00 Models
The shitt lever has six positions; El PARK, E REVERSE, E NEUTRAL. E ,lst through 4th ranges, and 1st through 3rd(when Over-Drive (O/D) is OFF) ranges. @ 2nd gear, and E 1st gear.
Starting is possible only in @ and @ positions. using a slide-type. neutral-safety switch.
Automatic Transaxle (A/T) Gear Position IndicatorThis indicator in the instrument panel shows which gear has been selected.
Transler Mochanism {4WD}
The transfer mechanism consists of the transfer shaft drive gear. the transfer shaft. the transfer drive gear, the transfer driv-en gear shaft, and the companion flange, The transfer mechanism assembly is on the rear side ot the transmission. besidethe differential. The transfer shaft drive gear on the final driven gear drives the transfer shaft driven qear. power is transmit-ted to the rear differential via the transfer shaft and the Drooeller shaft.
Clutches
The four-speed automatic transmission uses hydraulically-actuated clutches to engage or disengage the transmission gears.When the hydraulic pressure is introduced into the clutch drum, the clutch piston moves. This presses the friction discs andsteel plates together, locking them so they don't slip. Power is then transmifted through the engaged clutch pack to its hu$mounted gear. When hydraulic pressure is bled from the clutch pack, the piston releases the friction discs and steel plates, andthey are free to slide past each other. This allows the gearto spin independently on its shaft, transmitting no power.
lst Clutch
The 1st clutch engages/disengages lst gear, and is located at the end ofthe mainshaft, just behind the end cover.The 1st clutch is supplied hydraulic pressure by its ATF feed pipe within the mainshaft.
lst-hold Clutch
The 1st-hold clutch engages/disengages 1st-hold or E position, and is located at the middle of the sub-shaft. The 1st-holdclutch is supplied hydraulic pressure by its ATF feed pipe within the sub-shaft.
2nd Clutch
The znd ciutch engages/disengages 2nd gear, and is located at the middle of the mainshaft. The 2nd clutch is joined back-to-back to the 4th clutch. The 2nd clutch is supplied hydraulic pressure through the mainshaft by a circuit connected to theinternal hydraulic circuit.
PositionDescription
Reverse; reverse selector engaged with countershaft reverse gear and 4th clutch locked.
Allclutches released.
General driving; starts off in 1st, shifts automatically to 2nd, 3rd, then 4th, depending on vehicle speedand throftle position. Downshifts through 3rd,2nd, and lst on deceleration to stop.The lock-up mechanism operates;n 3rd and 4th gear.
used for rapid €cceleration at highway speeds and general driving; stans off in 1st, shifts automatically to2nd_then 3rd, dejending on vehicle speed and throttle position. Downshifts through lower gears on decel-eration to stop. The lock-up mechanism comes into operation in 3rd gear.
Driving in 2nd_gear; stays in 2nd gear, does not shift up and down. For engine braking or better trac_tion starting off on loose or slippery surfaces.
Driving in 1st gear; stays in 1st gear, does not shift up. For engine braking.
tll PARK
t!!l l|EvEn>E
E NEUTRAL
Ell DRrvE ('97 - sB)E DRrvE ('ss - oo)(1st through 4th )
E DRrvE {'97 - s8)O DRTVE with over-Drive (O/D) is OFF('99 - 00)(1st through 3rd)
E SECOND
E FIRST
14-4
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