ldle Control System
ldle Air Control llAC) Valve
The scan tool indicates Diagnostic Trouble Code (DTC) Pl508: A probtem in the ldle Air Controt flAC) varvecircuit.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM/PCM inorder to maintain the proper idle speed.
37 model;
IAC VALVE 2P CONNECTOR {C132}
,f rcp'# IYEL/BI.(II2f-1-d)
Y
Wir€ side of female terminals
PCM CONNECTOR A I32PI
tacvIBLK/BLU)
From AIR To INTAKECLEANER MANIFOLD
Wire side of female terminals
The MIL has beon .eport€d on.OIC Pl508 is sto.ed.
Problem veiification:1. Do the PCM Reset Procedure.2. Start the engine, and warm itup to normal operating tem-perature.
Inte.mittent failure, systcm b OKat thi3 time. Check tor poo. con-nections or loose wircs at C132(lAC v.lvel and at the PCM.
ls DTC Pl508 indicated?
Check lor an open in the wir6{lGPl lins}:1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON {ll).4. Measure voltage between bodyground and the IAC valve 2Pconnector term inal No.2.
Repair open in the wire trctwoontha IAC v!lv6 and the PGM-Flmain relly.
Chock for an opan o. short in thowi.e (lACv linel:1. Turn the ignition switch OFFand reconnect the IAC valve2P connector.2. Disconnect the PCM conneclorA (32P).
3. Turn the ignition switch ON {ll).4, Measure voltage betweenbody ground and PCM con-nector terminal A12.
{To page 1l-153)
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Fuel Supply System
Low Fuel Indicator System
Indicator Light Testing
NOTE: Refer to section 23forthe lowfuel lndicator circuit
clragram.
1. Check the No. 25 METER (7.5 A) fuse in the under-
dash fuse/relay box before testing.
2. Park the vehicle on level ground.
@ Do not smoke while working on the
fuel system. Keep open flame away trom the work
aroa. Drain fuel only into an approved container.
Drain the fuel into an aoDroved container. Then
install the drain bolt with a new washer.
Add less than 8 f (2.1 U.S. Gal. 1.8 lmp. Gal) of fuel,
and turn the ignition switch ON {ll). The low fuel indi-
cator light should come on within four minutes.
INDICATON LIGHT
. lf the light comes on within four minutes, go tostep 8.
. lf the light does not come on within four min-
utes. go to step 5.
Remove the seat cushion (see section 20).
Remove the fuel tank access panel from the floor,
and disconnect the 5P connector from the fuel pump,
Connect the No. 1 and No. 2 terminals with a jumper
wire.
. lf the lightcomeson, checkthe sending unit.. lf the light does not come on, check for:- an open in the GRN/yEL wire between thefuel unit and fuel gauge assembly.- blown bulb.- poor ground (G552).
FUEI- PUMP 5P CONNECTOR (C562)
JUMPER WIRE
IGRN/YEL}
7.
1 1-1 86
Wire sid€ ol tem€le terminals
8. Add 4 / of fuel (1.1 U.S. Gal, 0.9 lmp. Gal). The light
should go off within four minutes.
. lJ the light does not go off, check for:- a short in the GRNA/EL wire between the fuel
gauge sending unit and fuel gauge assembly.- faulty gauge assembly.
. lf the light goes off, the low fuel indicator light is
oK.
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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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Emission Control System
Evaporative Emission (EVAP) Controls (cont'd)
99 - 00 models:
The scan tool indicates Diagnostic Trouble Code {DTC) P0451: The Fuel Tank Pressure sensor circuit range/oerformance Droblem.
ECM/PCM CONNECTORS
SG2 {GRN/BLK)
Wire side of {emaleterminals
FUEL TANKPRESSURESENSOR
VACUUMPUMP/GAUGE.0 -30 in.H9A973X - 041 -
XXXXX
- The MIL har been rooort€d on.- DTC P0451 b storod.
Check lor th6 tu6l tank pr€ssurelen30r:1. Do the ECM/PCM Reset Proce,oure.2. Remove the fuelfill cap.3. Turn the ignition switch ON (ll).4. Monitor the FTP Sensor voltage with the Honda PGMTester, or measure voltagebetween ECM/PCM connectorterminals A29 and C18.
Chock tho vacuum lin6s torrGlriction o. blockago repair asnecessary. lf OK, roplace the fueltank Drer3ur€ sentor.
ls there approx. 2.5 V?
Check for the fuel tank piessureSensot:L Disconnect the hose betweenthe EVAP two way valve andthe fuel tank pressure sensor atthe EVAP two way valve end.2. Connect a vacuum pump tothe open end ofthat hose.3. Turn the ignition switch ON (lll.4. Monitor the FTP S€nsor volt-age with the Honda PGMTester, or measure voltagebetween ECNI/PCNI connectorterminals A29 and C18, andcarefully appiy vacuum on thehose one stroke at a time.5. The voltage should smoothlydrop from the staning approx.2.5 V down to approx. 1.5 V.STOP applying vacuum whenthe voltage drops to approx.1.5 V or damage to the tueltank pressure sensor may
Does the voltage drop to approx.1.5 V and hold?
Intermittent tailuro. sv3tem is OKat this tim€. Chack to. poor con-n€ction6 or 10036 hose at fu6ltank pres3ure ionsor and fueltrnk.
a t32Pl
PTANK ILT GRNI
WAY VALVE
11-208
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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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Circuit Diagram and Terminal Locationsr9T Model
IGNITIONSWITCH
LOC( UPCONTROL
LOCK UPCONTROLSOLEITOIDVALVE B
sf Frc0|lltF0LSOLENOIDVALVE A
sHrFr c0r{TnoLSOLEI{OID VALVE B
UNEASSOLINOID
14-21
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Description
Electronic Control System (cont'd)
Circuit Diagram and Terminal LocationsrgS Model
GNTIONSWITCN
LOCK-UPCONIFOLSOLEIIO D VALVE A
LOCK-UPCONTSOLSOLEI.IO 0 vALvE B
SBIFICONTROLSOLEI€ DVALVE A
SH FTCONTFOLSOLEiDID VALVE 8
LIN€AA SOL€iDIDGNIION SWTCHtGr
14-22
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