1996 HONDA CIVIC idle adjust

Removal
Engine removal is not required for this procedure.
!@@ Make sure jacks and safety stands are placed
properly and hoist brackels are attached to correst posi-
tion on the engine,
CAUTION:
o Use fender covers to avoid damaging painted sur-
faces.
To avoid damage, unplug the wiling connectors
carelully while holding the connector portion.
To avoid damaging the cylinder head, wait until the
engine coolant temperature drops below 100"F {38'Cl
before loosening the retaining bolt.
NOTE:
. Unspecified items are common.
. Mark all wiring and hoses to avoid misconnection.
AIso, be sure that they do not contact other wiring or
hoses or interfere with other parts.
o Inspect the timing belt before removing the cylinder
n eao.
. Turn the crankshaft pulley so that the No. 1 piston is
at top dead center (see page 6-64).
1. Disconnect the negative terminal from the battery.
Drain the engine coolant {see page 10-7).
. Remove the radiator cap to speed draining.
Remove the strut brace (see page 5-2).
Remove the intake air duct and air cleaner housing
(see page 5-3).
Remove the adjusting bolt and mounting bolt, then
remove the power steering (P/S) pump belt and pump
(see page 5 5).
2.
3.
4.
\
ADJUSTING
6. Loosen the idler pulley bracket bolt and adjusting
bolt, then remove the air conditioning (A/C) com-
pressor belt.
IDLER PULLEY BRACKETBOLT10 x 1.25 mm44 N.m {4.5 kg,l.m, 33 lbt.ft}
7. Loosen the mounting nut and lock bolt, then remove
the alternator belt.
LOCK BOLT8 x 1.25 mm24 N.m {2.4 kgf.m,17 tbtftl
ALTERNATORBELT10 x 1.25 mm,l,l N.m {4.5 kgf.m,33 tbf.ft,
(cont'd)
6-67

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

1.After the engine starts, the lAc valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is tow, the IAC valve is opened to obtain the proper fast idle speed. The amount of
bypassed air is thus controlled in relation to the engine coolant temperature'
IOLE SPEED
lrpml
176
80
ENGI ECOOLANI TEMPERATURE
t" Fl
toc)
ll
't.Whentheid|espeedisoutofspeciiicationandthescantoo|doesnotindicateDiagnosticTroub|ecode(DTc)P0505
or P1508. check the following items:
. Adiust the idle speed {see page 11-220}
. Starter switch signal (see page 11-202)
. Air conditioning signal (see page l1-204)
. ALT FR signal (see Page 11-2081
' Brake switch signal (see page 11-210)
. PSP switch signal (excapt Canada model) (see page 11-212)
. A,/T gear position signal {see section 14, Dl6Y5 engine (CVT):
page 11-216). Clutch switch signal (D16Y5 engine with M/T) (see page 11-218)
. Hoses and connections
' IAC valve and its mounting O-rings
lf the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 11-220)
|ftheid|espeedsti||cannotbeadjustedtospecification(andthescantoo|doesnotindicateDTcP0505orP]50S)
after IAC valve replacement. substitute a known-good ECM/PCM and recheck. lf symptom goes away, replace the
original ECM/PCM.

ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)

ldle Control System
ldle Speed Setting
Inspection/Adiustmenl
'96, '97 Dl6Y5. '96 - 00 Dl5Y8 sngine with M/T
NOTE:
. Before setting the idle speed, check the following
items:- The MIL has not been reported on.- lgnition timing- Spark plugs- Air cleaner- PCV system
o (Canada) Pull the parking brake lever up. Start the
engine, then check that the headlights are off.
1. Start the engine. Hold the engine at 3.000 rpm withno load (taansmission in neutral) until the radiatorfan comes on, then let it idle.
2. Connect a tachometer.
3. Disconnect the IAC valve connector.
4.lf the engine stalls, restart the engine with the accel-
erator pedal slightly depressed. Stabilize the rpm at1,000, then slowly release the pedal until the engineidles.
Check idling in no-load conditionsr headlights. blowerfan. rear defogger, radiator fan, and air conditioner
are not operating.
ldle spsed should be:
450 1 50 rpm
11-220
Adjust the idle speed, if necessary, by removing thecap and turning the idle adjusting screw.
NOTE; After adjusting the idle speed in this step,recheck the ignition timing (see section 23).
lf it is out of spec, go back to step 4.
IDLE
6. Turn the ignition switch OFF.
7. Reconnect the 2P connector on the IAC valve, then
do the ECM reset procedure.
8. Restart and idle the engine with no-load conditionsfor one minute, then check the idle speed.
NOTE: (Canada) Pull the parking brake lever up.Start the engine, then check that the headlights areoff.
ldle sp€sd should b€:
670 i 50 rpm IUSA)750 t 50 rpm {Canada}
9. ldle the engine tor one minute with headlights {Low)ON. and check the idle speed.
ldle speed should be:
750 :r 50 rpm
10. Turn the headlights off. ldle the engine for oneminute with heater fan switch at Hl and air conditioneron, then check the idle speed.
ldle speed should be:
810150 rpm
NOTE: lf the idle speed is not within specification,see Symptom Chan on page 11-84.

t
t
I
'96.'97 D16Y5 engine with CVT,'96 - 00 D16Y8 ongins
with A/T and'96 - 00 Dl6Y7 €ngine
Adiust the idle speed using a Honda PGM Tester if pos-
sible. lf not, use the following procedure:
NOTEI
. Leave the IAC valve connected
. Betore setting the idle speed. check the following
items:- The MIL has not been reported on'
- lgnition timing
- Spark Plugs- Air cleaner- PCV system
1. Connect a tachometer.
2. Start the engine. Hold the engine at 3,000 rpm wirh
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
3. Check the idle speed with no-load conditions: head-
iights, blower fan, rear defogger, radiator fan, and
air conditioner are not operatlng
ldl€ spoed should be:
USA:
D16Y5 engine with CVT, D16Y7 engine with A/T'
Dl6YB engine with A/T:
700 :r 50 rpm (in E or El Positionl
D16Y7 engine with M/T:
670 i 50 rpm
Canada:
Dl6Y8 sngin€, Dl6Y7 engins:
M/T750 t 50 rpm
NT750 1 50 rpm (in E or El Position)
Adjust the idle speed, if necessary, by removing the
cap and turning the idle adiusting screw 1/2-turn
clockwise or counterclockwise
D16Y5, D16Y8 engine:
IDLEADJUSTING
Dl6f, ongine:
NOTE: When you remove the ACL housing, do not
disconnect the IAT sensor connector
After turning the idle adjusting scrow 1/2-turn'
check the idle speed again. lf it is out of spec, turn
the idle adjusting screw 1/2-turn agaan'
NOTE: Do not turn the idle adjusting screw more
than 1/2-turn without checking the idle speed'
ldle the engine for one minute with heater fan
switch at Hl and air conditioner on, then check the
idle speed.
ldle speed should be:
M/T810150 rpm
A/T. CvT810 t 50 rpm (in El or E Position)
NOTE:
. Do not turn the idle adjusting screw when the air
conditioner is on.
. lf the idle speed is not within specification. see
Symptom Chart on page 11-84 (cont'd)
11-221

ldle Control System
ldle Speed Setting (cont'dl
Inspeqtion/Adiustment
38 D16Y5 engine whh M/T,'99 - 00 81642 engine
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 withno load (transmission in neutral) until the radiatorfan comes on, then let it idle.
Connect a tachometer.
Disconnect the IAC valve 2P connector and the EVAPpurge controlsolenoid valve 2P connector.
EVAP PURGECONTROLSOLENOID VALVE
lf the engine stalls, restart the engine with the accel-erator pedal slightly depressed. Stabilize the rpm at1.000, then slowly release the pedal until the engineidles.
Check idling in no-load conditions: headlights, blowerfan, rear defogger, radiator fan, and air conditionerare not operating.
ldl€ speed should be:
450 i 50 rpm
11-222
lf necessary, adjust the idle speed, by removrng lnecap and turning the idle adjusting screw.After adjusting the idle speed recheck the ignitlontiming (see section 23). lf it is out of spec, go backto step 4. |DLE
6. Turn the ignition switch OFF.
7. Reconnect the 2P connectors to the IAC valve andthe EVAP purge control solenoid valve, then do theECM reset procedure.
8. Restart and idle the engine with no-load conditionsfor one minute, then check the idle sDeed.ldle speed should bo:
USA:
D16Y5 engine: 670 i 50 rpm
81642 engine: 700 i 50 rpm
Canada:
81642 engine: 750 t 50 rpm
NOTE: lf the idle speed increases to 8lO t 50 rpm,this means the EVAP system is purging the canister.To stop the purging temporarily, raise the enginespeed above 1,000 rpm with the accelerator pedal,
then slowly release the pedal.
9. ldle the engine for one minute with headlights(Low) ON. and check the idle speed.
ldle speed should be:
750 i 50 rpm
10. Turn the headlights off. ldle the engine for oneminute with heater fan switch at Hl and air condi-tioner on, then check the idle soeed.ldls speed should be:
810 t 50 rpm
lf the idle speed is not within specification, seeSymptom Chart on page 11-84.

\
I
'98 - 0O D16Y5 ongine with CvT
Adjust the idle speed using a Honda PGM Tester if pos-
sible. lf not, use the following procedure:
NOTE:
. Leave the IAC valve connected.
. Before s€tting the idle speed, check the following
rtems:- The MIL has not been reported on.
- lgnition timing
- Spark Plugs- Air clean€r
- PCV svstem
'1. Connect a tachometer.
2. Stan the engine. Hold the engine at 3,000 rpm w'th
no load (transmission in E or E] position) until the
radiator Jan comes on, then let it idle.
3. Check the idle speed under no-load conditions:
head lights, blower fan, rear defogger, radiator fan,
and air conditioner are not operatlng.
ldlo spaod ehould bo: 700 t 50 rpm
. lf the idle speed is within the specification, the
procedure is comPlete.
. lf the idle sDeed is out of specitication, 9o to step 4'
4. tf the idle speed is 810 1 50 rpm, this means the
EVAP system is purging the canister. To stop the
purging temporarily, raise the engine speed above
l,OO0 rgm with the accelsrator pedal. Slowly release
the pedal. and rscheck the idl€ speed.
. tf the idle speed is within the specificstion, the
Drocedure is comPlete.
. lf the idle sp€ed is out of spocification, go to step 5.
5. Disconnect th€ EVAP purgs control solenoid valve
2P connector.
EVAP PURGECONTROL
6. Remove the cap and turn the idle adiusting screw
1/2-turn clockwise or counterclockwlse
IDLE
7.After turning the idle adjusting screw 1/2-turn, check
the idl€ speed again. lf it is out of spec, turn the idle
adjusting screw 1/2-turn again.
NOTE: Do not turn the idle adjusting screw more
than 1/2-turn without checking the idle speed.
Turn the ignition switch OFF. Reconnect the EVAP
purge control solenoid valve 2P connector' then do
the ECM reset Procedure.
Start the engine. ldle the engine for one minute with
heater fan switch at Hl and air conditioner on, then
check the idle speed.
ldle spaed should be:
810 t 50 rpm (in El or E Posiiion)
lf the idle speed is not within specification, see
Svmptom Chart on Page 11-84.
9.
SOLENOID VALVE
11-223