vtec control system HONDA CIVIC 1996 6.G Workshop Manual

Cylinder Head/Valve Train
Dl6Y5, D16Y7, Dl6Y8 engines
Special Tools ............. G2
VTEC Control System
Troubleshooting Flowchart .........." 6-3
VTEG Solenoid Valve
Inspection ............" 6-6
VTEC Rocker Arms
Manual lnspection
(D16Y5 engine) ............................. 6-7
Manual Inspection
(D16Yg enginel ................'............ 6-7
Inspection Using Special Tools
{D16Y5 engine} .....................""'... 6-8
Inspection Using Special Tools
(D16Y8 engine) .........................'.'. 6-10
Valve Clearance
Adiustment ..."".....6-12
Valve Seals
Replacement (Cylinder head removal
not requiredl ................................ 6-1tl
Crankshaft Pulley and PulleY Bolt
Replacement ."...... &16
Timing Selt
lllustrated Index ............................... 6-17
Inspection .............. 6-18
Tension Adjustment ........................ 6- 1 I
Removal ......,,......... 6-19
lnstallation ............. 6-20
Crankshaft Speed Fluctuation (CKF) Sensor
Repf acement .........6'22
Cylinder Head
lllustrated Index ............................... 6-23
Removal ................. 6-27
Warpage ................ 6-40
lnstallation ............. 6-45
Rocker Arms
Removal ................. 6-30
Disassembly/Reassambly ............... 6-31
Rocker Arms and Lost Motion Assemblies
Inspection (D16Y5, D16Yg
enginesl "..........' 5-34
Rocker Arms and Shafts
Glearance Inspection ....................... 6-35
Camshaft
Inspection .............. 6-36
Valves, Valve Springs and Valve Seals
Removal ........""..... 6-38
Valve Guides
Valve Movement .............................. 6-39
Replacement .........6-41
Reaming .......'......'.' 6-43
Valve Seats
Reconditioning .'....6'40
Valves
lnstallation ............. 6-tt3
Camshaft/Rocker Arms and
Camshaft Seal/Pulley
lnstallation ............. 6-44

VTEC Control System
Troubleshooting Flowchart
tFtrsrl #ilH:::lj1t:"J:T,?ffnostic
rrouble code (Drc) Pr25e: A probrem in the vrEc Pressure switch circuit or
Reter to page 1 l-38 th roug h 1 1-55 before trou bleshooting.
* Road Test:Accelerate in 1st gear to an engine speed over 3,000 rpm(D16Y5 engine) or 6,000 rpm (D'16Y8 engine).Hold that engine speed for at least two seconds.It DTC P1259 is not repeated during the first road test, repeatthis test two more tames.
VTEC PRESSURE SWITCH 2PCONNECTOR
Terminal side ofmale terminals
Wire sid6 ol femalerermtnats
VTM
l1 (BLu/BLK)
f;-) |I
I
Y
I
The MIL has been reoorted on.DTC P1259 is sto.ed.
Check the VTEC Cont.ol Syst6m:1. Do the engine control module(ECM)/powertrain control module lPCM) Reset Procedure (see
section 11).2. Stan the engine.3. Warm up the engine to normaloperating temperature (cool-
ing fan comes on).4. Do the Boad Test.*Intermittont tailura, 3y3t.m is OKat thia time.Check for ooor connoctionr o.loose wirea at VTEC oiassurclwitch, VTEC solonoid valvo .ndECM/PCM,
ls OTC P1259 indicated?
Test rhe VTEC Prensure Switch:1. Turn the ignition switch OFF.2. Disconnect the VTEC Pressureswitch 2P connector.3. Check for continuity betweenVTEC pressure switch 2P con-nector terminal No. 1 and No.2.
Replace the VTEC preasure 3witch.ls there continuity?
Te3t the VTEC Pressure SwitchWire:1. Turn the ignition switch ON lll).2. Measure the voltage betweenVTEC press u re switch 2Pconnector No. l and bodyground.
In3poct for en opon or shod toground in thG wi.. bctwoon thoVTEC pro$ur6 switch rnd ECM/PCM l'96 - 9a: C15,'99 - 00: C101.lf tha wiro i3 OK,3ubrtitute aknown-good ECM/PCM andrecheck.
ls there battery voltage?
{To page 6'4i

I
VTEC Control System
Troubleshooting Flowchart (cont'd)
VTEC PRESSURE SwlTCH 2PCONNECTOR
Wire side of female(€rmrnats
VTEC SOLENOID VALVE lPCONNECTOR
I r----'t I
ll ' ff---r'-'1
I
I
-L
Terminal side ofmale terminal
A/T LOW PRESSUREw/PAt{EL07406-0070300
NOTE: Keep measuring time as short aspossible because engine is running with noload (less than one minute).
PRESSURE GAUGEADAPTER07NAJ - P07010A
A/T PRESSURE I{OSE07406 - 0020201
ot
A/T PRESSURE HOSE.2,210 mm07MAJ - PY&llA andA/T PRESSURE ADAPTER07MAJ - PY,()120
6-4
(From page 6-3)
(To page 6-5)
Test the VTEC Pr6suro SwitchWiro:Nleasure voltage across the VTECpressure switch 2P connector.
. Rcpai. opon in tho wirebrtw.en VTEC pr6.urc switchand G101.. lf th. wir6 b OK, sub.thuto alnown-good ECM/PCM !ndracheck.
ls there baftery voltage?
Te3t the VTEC Solonoid V.lve:1. Turn the ignition switch OFF.2. Disconnect the VTEC solenoidvalve 1P connector.3. Check for continuity betweenthe VTEC solenoid valve 1Pconnector terminal No. 1 andbody ground.
ls there 14 - 30 0?
Te3t tho WEC Solonoid Vatvo:'1. Remove the VTEC pressureswatch and install the specialtool as shown, then reinstallthe VTEC pressure switch.2. Reconnoct the VTEC solenoidvalve 1P connector and VTECpressure switch 2P connector.3, Connect the tachometer (seesection 11).4. Stan the engine.5, Warm up engine to normaloperating temperature (cool,ing fan comes on).6. Check oil pressure at enginespeeds D16Y5 engine: 1,000and 3.000 rpm, D16Y8 engine:1,000,3,000 and 5,000 rpm.
ls pressure below 49 kPa(0.5 kgflcm,, 7 psi)?In.poct the VTEC aolonoid vllvols.c p.g. &6).
:(
t
I
t
:
t
I
I

VTEC Control SYstem
The scan tool indicates Diagnostic Trouble Code {DTC) Pl259:
VTEC Solenoid Valve circuit
Refer to page 1'l-38 through 11 55 before troubleshooting
Troubleshooting Flowchart
YES
A problem in the WEC Pressure Switch circuit or
* Road Test:Accelerate in 1st gear to an engine speed over 6,000 rp '
Hold that engine speed for at leasttwo seconos'
lf the DTC P1259 is not repeated during the first road test'
repeat this test two more times
VTEC PRESSURE SWITCH 2P
CONNECTOR
Terminalside ofmale termtnals
WM
/1 IBLU/BLKI
/ 1 Y------rt--------- l I
\1-/ |I
I
I1
Wire side of femaleterminals
(cont'd)
6-51
The MIL has been teported on.
DTC P1259 is siored.
Check the VTEC Control SYsiem:
1. Do the engine control module(ECM ) Reset Procedure (see
section 11).
2. Start the engine
3. Warm uP the engine to normal
operating temPerature (cool
ing fan comes on).
4. Do the Road Test.*lntermittent failure, sYstem is OK
at this time.Check for Poor connectlons or
loose wires at VTEC Pressureswilch. VTEC aolenoid valvo and
ECM.
ls DTC P1259 indicated?
Test the VTEC Pressure Switch:
1. Turn the ignition switch OFF.
2. Disconnect the VTEC Pressure
switch 2P connector.
3. Check for continuity between
VTEC pressure switch 2P con
nector telminal No 1 and
No.2.
Reolace the VTEC Pre3sure switch.
Test the VTEC Pressure Switch
Wire:1. Turn the ignition switch ON (ll).
2. N4easure the voltage between
VTEC press u re switch 2P
connector No. 1 and bodyground,
Inspect lor an open or short toground in the wire between the
VTEC orassure swilch and ECM
{c101.lf the wire i3 OK, substitute a
known-good ECM and recheck.
{To page 6 52)

VTEC Control System
Troubleshooting Flowchart (cont,d)
VTEC PRESSURE SWITCH 2PCONNECTOR
Wire side of temaleterminals
OIL PRESSURE GAUGE(Comm.rcially avail.bte)
GAUGE JOINT ADAPTERSNAP.ON MT26.1710 x 1.0 ftm. Use new washer wheninstalling the sealing bott.
NOTE: Keep measuring time as shorr aspossible because engine is running witn noload lless than one minute).
6-52
(
VTEC SOLENOID VALVE lPCONNECTOF
Ir------r I
lLl.ll-r
II
It
Terminal side ofmale terminal
I
(From page 6-5l l
(To page 6-53)
Test tha VTEC P.es3uro SwitchWi.e:Measure voltage across the VTECpressure switch 2P connector.
Ropair opon in the wiro batwoenVIEC pr...urc switch and G lot .lf the wiro is OK, 3ubltitutr aknown-good ECM and rochack.
ls there battery voltage?
Test the VTEC Solenoid V.tve:1. Turn the ignition switch OFF.2. Disconnect the VTEC solenoidvalve 1P connector.3. Check for continuity betweenthe VTEC solenoid valve 1Pconnector terminal No, I andbody ground.
ls there 14 - 30 O?
Te3t the VTEC Sotonoid Vatve:'1. Remove the VTEC pressureswitch and install the specialtool as shown. then reinstallthe VTEC pressure switch.2. Reconnect the VTEC solenoidvalve 1P connector and VTECpressure switch 2P connector,3. Connect the tachometer (seesection 1l).4. Start the engine.5. Warm up engine to normaloperatrng temperature (cool-ing fan comes on).6. Check oil pressure at enginespeed of 1,000,3,000 and5,000 rpm.
ls pressure below 49 kPa(0.5 kgflcm,,7 psi)?Inipoct thg VTEC aolenoid valvel3ee P8go 6-54).
I

System Description
Electrical Connections ('99 - 00 Models except Dl6Y5 engine with M/Tl
(cont'd)
T:I
1
0
EVAP PURGE CONTROLSoLENOtOVAIVEc26 ECTECTSENSOR
D
EVAP COI{TROL CANISIE R
IATSENSOR
ta-t
c25 tAT
HO2S(sENSoFt
EVAP BYPASS SOI.ENOID VALVE
cl Po2s{tc"Eso! 87
)wEGF coNTRoL solENoro vaLvE'"c16PHO2S
vlsBr2VTEC SOLEr{O|D VATVE
H02SiSENSOR 2),wA23 SHO2S
VTECPFESSUFESWITCH
sEt{soR
-t,.1 f
I
BRAKE SWITCH
c7 sG1
SENSOB(Buln l oF
@E
lfil
*_r
/V | GAUGE
* lassEMBLIIl-
SPEEOSENSOR
tr
D5VBSOLo4tND A14
N DTI
NC DTOSPEEDSENSOR
LS+ Bl7UNEAR SOLENOID VALVET'I AT?04LS- a3
LOCIPr. l03alP03LCA 01P CONTBOISOIENOiDVALVE BLCB 03IOI{IROL SOLENOID VAIV€ A
SHIFI COTITROL SOLENOID VALVE BSHE D2
POStTtON
t----
I
To IIIT!FLOCK CONTROL UNIT
--t
L
l-
I
I
11-40
-.._.._.._.._l
,'-J

System Description
Electrical Gonnections ('99 - 00 Models except Dl6yS engine with M/T)(cont'd)
cad__J
neozvef- -l
q30
1""
h/wFDlt+l-lvss
EVAP CONTROLCANISTEF VENTSHUI VALVE
l,,"
I
Fl
TI
| "u,LB|.X'--Jf-ll
PsP swrcH'
VTECsoLEt{otoVALVE
cliaBLTC.YEL ----J----]
neo,"yrr.'--{l- ---5 |EVAP PUBGECONTROLSOLENOIDVALVE
clat
11-44

PGM-FI System
System Description
CKP/TDC/CYP Sensor
MAP Sensor
IAT SensorTP SensorEGR Valve Lift Sensor*'Primary H02SSecondary HO2SVSSBARO SensorELD*'KS€Starter SignalALT FR SignalAir Conditioning SignalA/T Gear Position SignalBattery Voltage {lGN.1}Erake Switch SignalPSP Switch SignalFuel Tank Pressure Sensor*iVTEC Pressure Switch*5Clutch Switch Signal*6Countershaft Speed SensornBMainshaft Speed Sensorrs
-\
----t /
F;ilrr j"-----fi-tri-'r.;l
Fb"t."'i" d" c;;il
F,h"'c;;tr*".io";-l
@."r.l"sc;;ll
EaM/PcM B""k-p F"""till
r\
-:/
Fuel IniectorsPGM-Fl Main Belay {Fuel Pump)MILIAC Valve!y'C Compressor Clutch RelayRadiator Fan Relay*,Condenser Fan RelayALT*'lcMEVAP Purge Control Solenoid
Primary HO2S HeaterSecondary H02S HeaterEGR Control Solenoid Valve*rEGR valve*6EVAP Bypass Solenoid Valve*'EVAP Control Canister Vent Shut
VTEC Solenoid Valve*5DLCLock-up Control Solenoid Valve*aShift Control Solenoid Valve*3Linear Solenoid Valve*3
*1: Dl6Y5 engine*2: USA model*3: CW (D16Y5 ensine), D16Y8 engine and 81642 ensine*4: '96 D16Y8 engine lcoupe),'97 Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model),'97 D16Y8 engine {coupe: all models, sedan: KLmodel),'98-all models,'99'all models,'00-all models+5: D16Y5, D16Y8,816A2 engine*6: M/T (D16Y5 enginei*7: CVT 1D'l6Y5 engine)+8: A/T (D16Y7, D16Y8 engine)*9: '96 D16Y5 engine,'96 D16Y7 engine,'96 Dl6Y8 engine (sedan),'97 D16Y5 engine,'97 Dl6Y7 engine (coupe: KA, KC models, sedan:KA, KC, KL (LX) models, hatchback: all models),'97 D16Y8 engine (sedan: KA, KC modelsi
PGM-FI Sy3lem
The PGM-Fl system on this model is a sequential multipon fuel injection system.
Fuel iniector Timing and Duration
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold air flow rates.
The basic discharge duration, after being read out from the memory. is further modified by signals sent from various sen-
sors to obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve llAC Valve)
When the engine is cold. the A,/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
. The ECM/PCM contains memories for basic ignition timing at various engine speeds and manifold air flow rates.
lgnition timing is also adjusted for engine coolant temperature.
. Aknockcontrol system was adopted which sets the ideal ignition timing for the octane rating ofthegasoline used.*3
Othgr Control Funqtions
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, the ECM/PCM supplies ground to the PGM-Fl main relay that sup-plies current to the fuel pump for two seconds to pressurize the fuel system.. When the engine is running, the ECI\4PCM supplies ground to the PGM-FI majn 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.
11-104
INPUTS
ENGINE CONTROL MODULE (ECMY
POWERTRAIN CONTROL MODULE (PCM) OUTPUTS

PGM-FI System
Fuel Supply System
D017-il Th""""ntool indicates Diagnostic Troubte Code {DTC) p0171;Thefuet system istoo lean.
1P0172 | fne scan tool indicates Dlagnostic Trouble Code (DTC) P0172:Thefuel system istoo rich.
Description
By monitoring the Long Term Fuel Trim, 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 P0172 will bestored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0171 andlot P0172, ltouhleshoot those DTCSfirst. then recheck for DTC P0l7l andlot P0172.
P0106-8, P1128*3. *5, P1129*3 *5 MAP Sensor
P0135; Primary HO2S Heater
P0137. P0138: Secondary HO2S
P0'141: Secondary HO2S Heater
P0401: EGR Flow Insufficient*1
P0441: EVAP System Insufficient Purge Flow*6
P1259: VTEC System*,
P1491:EGR Valve Lift Insufficient*r
P1498: EGR Valve Lift Sensor Hjgh Voltage*r
*r: D16Y5 engines*': Dl6Y5, D16Y8, 81642 engine*3: '97 models*a:'96 modelsf 5: '98 - 00 models*6: '96 D16Y5 engine,'96 D16Y7 engine,'96 D16Y8 engine (sedan),'97 D16y5 engine,,97 D16y7 engine (coupe: KA, KC mo+els, sedan KA. KC, KL (DX) models. hatchback; all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
DTC P0'171
loo lean
DTC P0172
too rach
Fuel Pump insuff icient f lovpressure
Fuel Feed Line clogged, leaking
Fuel Pressure Regulator stuck open
Fuel Filter clogged
Fuel Injector clogged, air inclusion
Gasoline doesn't meet Owner's Manual spec.
Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*.
EGR System malfunction (too much flow)*1
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closed
Fuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*a
EGR System insufficient flow*1
EVAP Purge Control Solenoid Valve leaking, stuck opened
Valve Clearance
11-164

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected. the MIL will blink during the time of its occurrence, and DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through P0304 will be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC. troubleshoot those DTCS first, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304