1997 HONDA CIVIC IAT sensor

Description
The Continuously Variable Transmission (CVT) is an electronically controlled automatic transmission with drive and driv
en Oullevs, and a steel belt. The CVT provides non stage speeds forward and one reverse. The entire unit is positioned in
line with the engine.
Transmission
Around the outside of the flywheel is a ring gear which meshes with the starter pinion when the engine is being staned.
The transmission has four parallel shafts: the input shaft, the drive pulley shaft. the driven pulley shaft, and the secondary
gear shaft. The input shaft is in line with the engine crankshaft. The drive pulley shaft and the driven pulley shaft consist of
movable and fixed face pulleys. Both pulleys are linked by the steel belt.
The input shaft includes the sun gear. The drive pulley shaft includes the forward clutch which mounts the carrier assem-
bly on the forward clutch drum. The carrier assembly includes the pinion gears which mesh with the sun gear and the ring
gear. The ring gear has a hub-mounted reverse brake disc.
The driven pulley shaft includes the start clutch and the secondary drive gear which is integral with the park gear' The sec-
ondary gear shaft is positioned between the secondary drive gear and the final driven gear. The secondary gear shaft
includes the secondary driven gear which serves to change the rotation direction. because the drive pulley shaft and the
driven oullev shaft rotate the same direction. When certain combinations of planetary gears in the transmission are
engaged by the clutches and the reverse brake, power is transmitted from the drive pulley shaft to the driven pulley shaft
to provide E, E, E, and El.
Electronic Control'96 - 98 Models:
The electronic control system consists of the Transmission Control Module (TCM), sensors, three linear solenoids, and a
inhibitor solenoid. Shifting is electronically controlled under all conditions'
The TCM is located below the dashboard, behind the kick panel on the driver's side.'99 - 00 Models:
The electronic control svstem consists of a Powertrain Control Module (PCM), sensors, three linear solenoids and an
inhibitor solenoid. Shifting is electronically controlled under all conditions. A Grade Logic Control System to control shift-
ing in E position while the vehicle is ascending or descending a slope.
The PCM is located below the dashboard, under the kick panel on the passenger's side.
Hydraulic Control
The lower valve body assembly includes the main valve body, the Pressure Low (PL) reguiator valve body, the shift valve
body, the start clutch control valve body, and the secondary valve body. They are positioned on the lower part of the
transmission housing.
The main valve body contains the Pressure High (PH) control valve, the lubrication valve, and the pitot regulator valve.
The secondary valve body contains the PH regulator valve, the clutch reducing valve, the start clutch valve accumulator,
and the shift inhibitor valve. The PL regulator valve body contains the PL regulator valve and the PH-PL control valve
which is ioined to the PH,PL control linear solenoid. The inhibitor solenoid valve is bolted on the PL regulator valve body.
The shift valve body contains the shift valve and the shift control valve. which is joined to the shift control linear solenoid.
The start clutch control valve body contains the start clutch control valve, which is joined to the start clutch control linear
solenoid. The linear solenoids and the inhibitor solenoid are controlled by the TCM or PCM. The manual valve body which
contains the manual valve and the reverse inhibitor valve, is bolted on the intermediate housing.
The ATF pump assembly is located on the transmission housing, and is linked with the input shaft by the sprockets and
the sprocket chain. The pulleys and the clutch receive fluid from their respective feed pipes, and the reverse brake receives
fluid from internal hydraulic circuit.
Shift Control Mechanism
Input from various sensors located throughout the vehicle determines which linear solenoid the TCM or PCM will activate.
Activating the shift control linear solenoid changes the shift control valve pressure, causing the shift valve to move. This
pressurizes the drive pulley pressure to the drive pulley and the driven pulley pressure to the driven pulley and changes
their effective pulley ratio. Activating the start clutch control linear solenoid moves the start clutch control valve. The start
clutch control valve uncovers the port, providing pressure to the start clutch to engage it(cont'd)
14-195
,!

t.
rl,
fl,
PROBABLE CAUSE LIST
Low CVT fluid level
ATF pump worn. AT gears worn or damaged. Foreign material in ATF pump.
ATF pump chain/ATF pump sprocket worn or damaged.
Input shaft worn or damaged.
Sun gear worn or damaged.
Final driven oear worn or damaqed,
Secondary drive gear/secondary driven gear worn or damaged-
5
6
1
8Flywheel/drive plate worn or damaged.
Intermediate housing assembly worn or damaged.9
'10Forward clutch defective.
Shift cable broken/out of adiustment.
M"nu"t t"uffi
ATF feed pipe (pulley pressure) worn or damaged.
Vchiclc speed sensor defective.
TCM or PCM defective.
Reverse brake detective.
1'r
't2
13
14
16
'11
'18
1qPlanetary gear worn or damaged.
Sta rt clutch defective.
ATF feed pipe (start clutch pressure) worn or damaged
20
t't
Clutch clearance/reverse brake clearance incorrect.
23Reverse brake return spring/retainer worn or damaged
24Needle bearing on input shaft worn or damaged.
25Thrust needle bearing on carrier worn or damaged.
Thrust washer on carrier worn or damaged.
Enoine outout low.------------------------
Flvwhcel assemblv defective.
Control lever worn or damaged.
Park pawl/park pawl shaft worn or damaged
Detent lever/park brake rod assembly worn or damaged
27
29
30
32Park gear worn or damaged.
Park pawl spring worn or damaged.
ATF strainer/ATF filter clogged.
Lower valve body assembly defective.
Lower valve bodv assemblv defective (PL regulator valve body assembly defective)'
33
34
50
Lower valve bodv assembly defective (shift valve body assembly defective).
Lower valve bodv assemblv defective (start clutch control valve body assembly defective)'
39Lower valve bodv assemblv defective {inhibitor solenoid defective}
40Solenoid harness worn or damaged.
Manual valve body worn or damaged.
PB feedback system defective.
CVT fluid deteriorated.
41
43
14-295

Road Test
NOTE: Warm up the engine to normal operating temperature (the radiator fan com6s on).
1. Apply the parking brake and block the wheels. Start the engine, then shift to the E position while depressing the
brake pedal. Depress the accelerator pedal and release it suddenly. The engine should not stall.
2. Test in E position
Park the vehicle in a slope (approx. 16'). apply the parking brake, and shift into E position. Release the brake; the
vehicle should not move.
3. Test-drive the vehicle on a flat road in the position shown in the table. Check that the engine speeds meet the approx-imate vehicle speeds shown in the table.
NOTE: Throttle position sensor voltage represents the throttle opening. To monitor the throttle position sensor volt-age, use one of the following methods:
A. Connect the Honda PGM Tester, and go to the PGM-FI Data List.
A1For road testing on '96 - 98 models, remove the drive/s side kick panel to expose the TCM; on '99 - OO models,remove the passenger's side kick panel to expose the PCM (see page l,[-236),
Set the digital multimeter to check throttle position sensor voltage between terminals:. '96 - 98 modols: TCM 84 {+} and Aa (-) or A17 (-1.. '99 - 0O models: FCM C27 {+l and 820 (-l ot 822 l-1.
DIGITAL MULTIMETER(Commerci.lly rvrilabl.lKS-AHM-32-003or oquivalant
BACKPROBE ADAPTER
BRN/BLK
A {26P1
TPS {BED/BLK}
'96 - 98 Models:
BRN/BLK
14-296
OBD ll SCAN TOOL orHONOA PGM TESTER
D{16Pt
Ware side ot female terminals
Wire side of female terminals

22. Install the shift cable end on the control lever, and
install the shift cable on the shift cable bracket'
CAUTION: Take care not to bend the shift cable'
23. lnstall the clip in the direction shown.
LOCKNUT
SHIFI CABLE 29 N m {3.0 kg{ m, 22lblftl
SHIFT CABLEERACKET
WASHERIPLASTIC)
CONTROL LEVER
24, Connect the solenoid harness connector. the drive
pulley speed sensor connector. and the ground
cable terminals.
6x1.0mm12 N.m {1.2 kgf.m.8,7 rbtft)
GROUND CABLETERMINAL 6x1.0mm
GROUNDTERMINAL
12 N.m {1.2 kgf'm,8.7lbtfrl
DRIVE PULLEYSPEED SENSORCONNECTOR
SOLENOID HARNESS
CONNECTOR
25. Connect the starter motor cable on the starter motor.
and install the cable holder.
NOTE: When installing the staner motor cable. make
sure that the crimped side of the ring terminal is
facing out (see section 23).
STARTEB
BMOUNTING NUT
9 N.m (0.9 kgf m,7 lbf ft)
26. Install all removed connectors and clamps'
27. Install the distributor.
28. Install the intake air duct and air cleaner housing
29.
assemDly.
Refill the transmission with the recommended
Genuine Honda CVT Fluid (see page 14-2991
CAUTION: While filling the CvT Fluid, bs surs not io
allow dust and other fotoign particles to entor into
the transmission.
Connect the battery positive (+) terminal first, then
the negative (-l terminal to the battery'
Check the ignition timing (see section 23).
Start the engine. Set the parking brake, and shift the
transmission through all gears three times Check
shift cable adjustment (see page 14-355).
Check the front wheel alignment (see section 18)
Let the engine reach operating temperature (the
radiator fan comes on) with the transmission in lXl
or E position, then turn it off and check fluid level'
Perform the start clutch calibration procedure on
page 14-293.
Road test as described on pages 14-296 and 14-297
30.
31.
34.
36.
STARTER MOTOR
14-351

Troubleshooting
Wheel Sensor
Diagnostic Trouble Gode {DTC) ll-18: Wheol S€n3ol DiagnosisNoTE: The ABS indicator light comes on when only the drive wheels are turning, signal disturbance is detected, etc. Therefore,test-drive the car at a speed of 12 mph (20 krn/h) or more after turning the ignition:witch from OFF to ON fll), and if the ABSindicator light does not come on, the svstem is OK.
0TcAppropriate Terminal(0)srDE11) SrD€r 1, 12 (Right-front)No.8: FRoNo.21: FRI13, 14 (Left-front)No. 10: FLoNo.23: FL115, 16 {Right-rear)No. {: RRoNo. 17: RRl17, 18 (Left-rear)No.6: RLoNo. 19: RLI
RLl (LT BLU}FRl (GRN/BLKI
Wire side ol female terminals
NO
NOTE:. Normal voltage: Approx.2 V' 0 V: Replace the ABS controt unit.. 4 V or more indicates a short to power.
A8S CONTROL UNIT 26P CONNECTOR
RRO
IBLU/YELI
RR1 IGRN/YELIFL1 IGRN/ORN}
- With the ignition switch ON{ll), ABS indicator tighr doe.noi go off,- Aftsr driving, ABS indicatotlight comes on.- With the SCS so.vice connac-tor conn€c,ted {soe pege 19-561,DTCs 11-18 a.e indicrted.
Chock lhe wheol sensor ci.cuit:1. Disconnect the ABS controlunit 26P connector.2. lleasure the resistancebetween the appropriate wheelsensor (0) and (1) circuit termi,
. Reprir op€n in the l0l or {0 cir-cuit wiro, or shon to thc {01 cir-cuit wi.o in thc {11 circuit wircbctween ths ABS control unitand approprieto wheel a6nsor.. R.pl.ce th€ epp.opri.te wheal3€nloa.
ls the resistance OK?
/Frontr 750 - 1050 o/20"C, 68.F \\Rear: 850- 1150 O/20.C, 68"F /
Check toru short to body groundin the wheel senso. circuit:Check for continuity between theABS control unit 26P connectorappropriate wheel sensor (0) circuit terminali and body ground.
. Rapair short to body ground inth6 (0) or lll cilcuit wi..bctwa.n th6 ABS control unitand appropdaie whoel lonsor.. Rep|'c6 tho appropriatc whcelsanlor.
Chock tor a sho.t to powe. in thowheel3en3or circuit:1. Reconnect the ABS control unit26P connector,2. Start the engine.3. Measure the voltage betweenthe ABS control unit 26P con-nector appropriate wheel sen-sor (0) circuit terminal andbody ground.
Ropair rhon to powo. in the l0lor lll circuit wire batw.en th€ABS cont.ol unit and .pplopriatawhccl !€naoa,
ls there 4 V or more?
fio page 19-65)
19-64

Contents
How to Use This Manual ICircuit Schematics (see Circuit Index)Fuse/Relaylnformation 6Ground-to-Componentslndex 6-6ComponentLocationPhotooraohs 201Conriector Views 202
Circuit Index
Accessory power socket 155Air conditionerAir delivery'96198 models 61'99-'00 models 61-2Blower controls'96198 models 60'99100 models 60-1Compressor controls 62Fans 63Anti-lock brake system (ABS) 44A/T gear position indicatorCVT 89All except CVT 89-1Automatic transmission controlsAll '96-'98 models except CVT and GX 39All '99100 models except CVT 39-8All GX models 39-8'96-'98 CVT 39-4'99100 cw 39-12Back-up lightsCoupe and Sedan 110Hatchback l'10-1Brake lightsAll Coupes and'96-'98 Sedans 110-15'99-'00 Sedans 110-16Hatchback 110-17Brake system indicator light'96198 models 7'1'99100 models 71-1Ceiling light 114-3Charging system 22Condenser fan 63Console lights 114Cruise control 34Dash lights 114Daytime running lights 110- 13Engine coolant temperature gauge 81-1Fog lights 110-10Front parking lights 110-2Fuel gauge 81-1Fuse/relay boxUnder-dash 6Under-hood 6-4Underhood ABS 6-3Gauges 81Ground distribution 14Ground-to-Componentslndex 6-6Hazard warning lightsAll except '99100 Sedans 110-6'99100 Sedans 110-8Headlights 110-12Headlight switch 100Heater - See Air ConditionerHorn'96197 models 40'98 model 40-1'99100 models 40-2lgnition key reminder 73lgnition systemAll '96198 models except Dl685 20All '99100 models except D16Y5 with Mn 2O-2All D1685 engines 20-2'99-'00 D 16Y5 with M/T 20
lndicators 80Integrated control unit 70lnterlock systemAll except'96J98 CVT 138'96198CVT 138-1License plate lightsAll Coupes and '96-'98 Sedans I l0-3'99100 Sedans 1 10-4Hatchback 110-5Low fuel indicator light 74Moonrool'96197 models |22'98-'00 models 122-1Odometer 81Oil pressure indicator light 80-3Power distributionBattery to ignition switch, fuses, and relaysFuses to relays and components 10-2Power door locksAll models without keyless entry 130'96-'98 models with keyless entry 130-2'99100 models with keyless entry 130-12Power mirrorsWithout detogger 141With defogger '141-2
Power windows 120Programmed fuel injection system (PGNr-Fl)All '96-98 models except D1685 23All '99-'00 models except D16Y5with M/T and D1685 24All D1685 engines 25'99100 D16Y5 with M/T 23Radiator fan 63Rear window defogger'96-,98 models 64'99100 models 64-1Seat belt reminder 73Security system'96.'98 USA HX, LX, EX 133'96-'98 Canada EX, Si 133'99TOO USA HX, LX, EX, DX.V Si 133-4'99100 Canada EX, Si 133-4All CX and DX models 133-8Speedometer 81Starting systemA./T (All except Dl685) 21A"/r (D16Bs) 21-1Manualtransmission 21-2Slereo sound system 150Supplemental rastraint system (SRS) 47Tachometer 81TailliqhtsAllboupes and'96-'98 Sedans 110-3'99100 Sedans 1 10-4Hatchback 110-5Trunk light 114-3Turn signal lightsAll except'99100 Sedans 110-6'99-'00 Sedans 1 10-8Vehicle speed sensor (VSS) 33Wiper/washerFront 91Rear 92
10

Ground-to-Components I ndex
f.,lONOTE: All ground wires are BLK unless otherwise noted.
GroundPageComponents or Circuit Grounded
Battery (BLKYEL)
Steering pump bracket
t+-rg ITransmission housing
l
G101
(-1)
G101
(-2)
14-2
and
14-3
ano
14-1
Powertrain or engine control module (PG1 and pG2 are BLK: LG1 and LG2 are
BRN/BLK), EGR control solenoid valve (CW, EGR valve and lift sensor (Dt6yS enginewith M,/T), Engine coolant temperature switch, pGM-Fl main relay, power steeringpressure switch (USA), Primary HO2S (D16Y5 engine with l\/,/T), Vehicle speed sensor,VTEC pressure switch (D16Y5/D16Y8 engines), CKF sensor (BRN/BLK), Transmission
control module (CYf) (Pc1 is BLK: LG1 is BRN/BLK)
Shielding betvveen the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor. Primary and secondary heated oxygen sensors.
Knock sensor (CWDl6YB engine), Mainshaft speed sensor (AiT except CVT),
I Countershaft speed sensor (A/T except CVf)
Shielding between the TCM and these components (CVT) (all have BRN/BLK wires):
Drive pulley speed sensor, Driven pulley speed sensor, Secondary gear shaft
speed sensor
Powertrain or engine control module (PG1 and pG2 are BLK; LG1 and LGz are
BRN/BLK), EGR control solenoid valve (D16Y5 engine), EGR valve (Dt685), Engine
coolant temperature switch, Fuel pressure regulator shut-off solenoid valve (D1685),
PGM-FI main relay, Power steering pressure switch (USA), Vehicle speed sensor, VTECpressure switch (All except D16Y7 engine), CKF sensor (A

except 81642) (BRN/BLK)
Shielding between the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor, Primary and secondary heated oxygen sensors,
Knock sensor (All except D16Y7 engine), i/ainshaft speed sensor (Arf except CW),
Countershaft speed sensor (A,/T except CVf), Drive pulley speed sensor (CW), Drivenpulley speed sensor (CVT), Secondary gear shaft speed sensor (CVf)
I Badiator fan motor, Right front parking/turn signat tight, Right headtight
G20214-4I Cruise control actuator, Left front parking/turn signal lights, Left headlight, Rear window
I washer motor, Windshield washer motor, Washer fluid level switch (,99-'00 Canada)
G401| +-o
and
14-7
Accessory power socket, Brake fluid level switch, Clutch interlock switch (M/T), Clutchswitch (lillT with cruise/D16Y5 engine with MfD, Combination wiper switch (Z wires),
Cruise control main switch, Cruise control unit, Dash lights brightness controller, Data
link connector, Daytime running lights control unit (Canada), Gauge assembly, Horn('96-'97 models), Integrated control unit, Interlock control unit (ArI), Keyless door lock
control unit ('99-'00 models with keyless), Moonroof close and open relays, Moonroof
switch, Park pin switch (A/r), Power window relay, Rear window defogger relay, Rear
window defogger switch ('96-'98 models), Steering lock, Stereo radio tuner (,96-,98
USA: LX, EX, and HX), Turn signal/hazard relay, Windshield wiper motor.....plus
everything grounded through G402
6-6

PGM-FI (All '9e'98 Models except D16B5; '99-'00 D16y5 with M/T)
- D16Y7 Engine
' I pressure Ret€rence sensor ECT IAT primary I' i sensor input , voltag€ input sensor rnput sensor inDut HO2S inout I| ! praNKi ' OCc2) irpsr (Ecr)' ,tAr) ' l"no)si- I, r (Pr^Nn, \wtz) {rPs) iEcr} (AT) {PHozs)lL-------J----- --_-__J: Dis y j oro y ory D2 y D8y D7y
i.--1*.".ffi,"[
',[
]ilBLKryEL
l='i$d""-""---ffi][.[
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iw| irT_nHBRrfrnEBsi+lrplffii.;t
llffit!$il
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phu Laa
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: 13 V"*3J
iclll ! 'e""
2Y lY LrGRN
'll---o19;.?:.,,GFN/
it io-rb as ; BtK I GFN BLX I GFN.BLK ll cRN BLk
(Termi-rl, lt nals, '97 model: I 8-14)r - - - California Coupe, ll PHoro 46Calitornia Sedan LX I I,E, J8'98 model: all
r (suzl lPo2sHrc) I! Sensor inmary'| 6rl1d Ho2s \
a - heater \
t control I,L------- -----J'
23-8