Heater valve HONDA CIVIC 1996 6.G User Guide

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

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

Start Clutch Control@
T
Start Clutch Calibration Procedure
NOTE: When the following parts are replaced, the TCM
must memorize the feedback signal for the start clutch
control.
. TCM
. Transmissionassembly
. Stan clutch assembly
. Lower valve bodv assembly
. Engine assembly or overhaul
'96 Model Only
CAUTION: Do not uso this procsdure on'97 - (X) mod-
els or you will damage the transmission. On '97 - 00
models, the TCM or PCM memorizes ths loodback sig'
nals when you drive the vehicle.
1. Engage the parking brake, and block the front
wheels securely.
2. Connect the SCS service connector to the Service
Check Connector as shown. (The Service Check
connector (2P) is located under the dash on the
passenger's side of the vehicle.)
CONNECTOR07PAZ - lDl01(xt
Start the engine, and warm it up to normal operat-
ing temperature (the radiator fan comes on twice).
Fully depress the brake pedal and accelerator for 20
seconds in the E] position.
rl ,
CONNECTOR I2PI
14-293
7.
Shift into E o|. E position. To store the engine
negative pressure in memory. Iet the engine idle in
E or E position for one minute under the follow-
ing conditions:
. With the brake pedal depressed,
. with the y'\/c switch oFF.
. With the combination light switch OFF.
. With the heater fan switch OFF.
. Turn OFF all other electrical systems
NOTE: Start step 5 within 60 seconds after the radi-
ator fan goes off.
Shift into E position, and let the engine idle for two
minutes to store the feedback signal in memory
under the same conditions as in step 5.
Connect the Honda PGM Tester. Check that the TCM
has completed the start clutch calibration.
NOTE:
. The TCM will not store the feedback signal when
the CVT fluid temperature is below 40"C (104'F)
even if the engine coolant temperature reaches
the normal operating temperature.
. Repeat these procedures until the start clutch
calibration is completed-
Disconnect the SCS service connector from the
Service Check Connector.
'97 - 00 Models
The TCM ('97 - 98 models) and PCM ('99 - 00 models)
memorize the feedback signal when you drive the
vehicle as follows:
. After warming up the engine (the radiator fan
comes onl.
. Shift into E position.
. Turn OFF all electrical systems,
. Drive the vehicle up to the speed 37 mph (60
km/h).
. After the speed reaches 37 mph (60 km/h),
release the accelerator for 5 seconds.

'99 - 00 Models
SRS components are located in this area, Review the SRS component locations, precautions, and procedures in the SRS
section (24) betore perfoming repairs or service.
HEATER UNITReplacement, page 21'39
Overhaul, page 21-41
BLOWEB UNITReplacement, page 21-37Overhaul, page 21 38
HEATER FANswtTcH
RECIRCULATIONCONTROL MOTORTest, page 21-48Beplacement, page 21-48
AIR MIX CONTROL MOTOBTest, page 21-46Replacement, page 21 46
BLOWERTest, page 21-49
POWER TRANSISTORTest, page 21 50
HIGH RELAY
MODE CONTROLDIALHEATER VALVE CABLEAdjustment, page 21 45TEMPERATURE CONTROLDIALAdjustment, page 21-45
REAR WINDOWDEFOGGERswtrcHSee section 23MODEMOTORTest, page 21 47Replacement, page 2 l-47A/C SWTTCH
lwith A/cl
CONTROL SWITCH
21-3

Troubleshooting -'96 - 98 Models
Symptom Chart
NOTE;
. Check the engine coolant level. and allow the engine to warm up before troubleshooting.
. Any abnormality must be corrected before continuing the test.
. Because of the precise measurements needed. use a multimeter when testing.
o Before performing any troubleshooting procedures check:- Fuses No. 41 11.5 Al, No. 55 (40 A) in the under-hood fuse/relay box. and No. 17 (7.5 A) in the under-dash fuse/relay
box- Grounds No. G401, G402- Cleanliness and tightness of all connectors
SymptomRomedy
Hot air flow is low.Blower motor runs. but one or more
speeds are inoperative.
Perform the procedures in the flowchart (see page 21-8).
Blower runs properly.Check for the following:. Clogged heater duct. Clogged heater outlet. Incorrect door position
No hot air flow.Blower motor does not run at all,Perform the procedures in the flowchart (see page 21-10).
Blower motor runs.Check for the following:. Clogged heater duct. Clogged blower outlet. Clogged heater valve. Faultv air mix door. Heater valve cable adjustment (see page 21-44). Air mix control cable adiustment (see page 2'l-441. Faulty cooling system thermostat (see section 10). Clogged evaporator (with air conditioning). Frozen evaporator {with air conditioning)
Mode control motor does not run, or one or more modes
are inooerative.
Perform the procedures in the flowchart (see page 21-13).
Recirculation control door does not chanqe between
FRESH and RECIRCULATE.
Perform the procedu.es in the flowchan (see page 21-16).
Both heater and A,/C do not work.Perform the procedures in the flowchart (see page 21-18),
21-6

Heater Unit
Replacement
SRS components are located in this area. Review the
SRS component locations, precautions, and procedures
in the SRS section {24} before performing repairs or ser-
L Disconnect the negative cable from the battery.
2. Frcm under the hood, open the clamp, then discon-
nect the heater valve cable from the heater valve
arm. Turn the heater valve arm to the fully opened
position as shown.
When the engine is cool. drain the engine coolant
from the radiator (see section 10).
!@ Do not remove the radiator cap when
the engine is hot; the ongine coolant is under pres'
surg and could severely scald you.
CLAMP
HEATER VALVC CABLE
4. Disconnect the heater hoses from the heater unit.
CAUTION: Engine coolant will damage p8int.
Ouickly rinse any spilled engins coolant from painted
su aces,
NOTE: Engine coolant will run out when the hoses
are disconnected; drain it into a clean drip pan.
5. Remove the mounting nut from the heater unit.
NOTE: When removing the mounting nut, take care
not to damage or bend the fuel lines, the brake
lines, etc.
I x 1 .25 mm22 N.m {2.2 kgl.m, 16lblftl
21-39