1996 HONDA CIVIC Engine control

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

Troubleshooting -'99 - 00 Models
Symptom
Mode control motor does not run, or one or more modes are inoperat've'
Recirculation control door does not change between Fresh and Recirculate'
Blower motor only runs on high speed position; it does not run in any other speed positions
Blower motor does not run at all.
Both heater and Ay'C do not work
See pags
a1_tq
21-21
21-29
21-31
21 35
Symptom Chart
For electrical malfunctions which are indicated by the self-diagnostic system, refer to self-diagnosis function (see next
page).
Note these items before troubleshooting a symptom'
. Check the engine coolant level, and allow the engine to warm up before troubleshooting'
. Any abnormality must be corrected before continuing the test
.Becauseoftheprec|semeasurementsneeded,UseadigitaImu|timeterwithanoutputoflmAor|essatthe20ko
range when testing
. Before performing any troubleshooting procedures check:
- Fuses No. 41 115 Al, No 55 (40 A)]n the under-hood fuse/relay box' and No 17 (7 5 A) in the under-dash fuse/relav
box- Grounds No. G401, G402
- Cleanliness and tightness of all connectors
21-19

Heater Unit
Replacement (cont'dl
6.
7.
8.
9.
Remove the dashboard (see section 20).
Remove the heater duct (see page 21-37) or evapo-
rator (see page 22-28).
Disconnect the connectors from the mode control
motor and air mix control motor ('99 - 00 models),
then remove the wire harness clips and wire har-
ness from the heater unit. Remove the clip from the
heater duct, then remove the two mounting nuts
and the heater unit.
6x1.0mm9.8 N.m 11.0 kgl.m,7.2 lbf.ftl
HEATER UNIT
lnstall in the reverse order of removal. Make note of
the following items.
Apply sealant to the grommets.
Do not interchange the inlet and outlet heater
hoses. Make sure that the clamps are secure.
Refill the cooling system with engine coolant
(see section 10).
Connect all cables, and make sure they are prop-
erly adjusted (see page 21-44 (96 - 98 models)
or page 21-45 ('99 - 00 models)).
Make sure that there is no air leakage.
21-40

A/C System Service
Performance Test
The performance test will help determine if the air con-
ditioner system is operating within specifications.
Use only service equipment that is U.L.-listed and is cer-
tified to meet the reouirements of SAE J2210 to remove
HFC-134a (R-134a) from the air conditioner system.
CAUTION: Exposure to air conditionor rofrigerant and
lubricant vapor or mist can irrilalo €yes, nose and
throat. Avoid breathing tho air conditioner rstrigerrnt
and lubricant vapor or mist,
lf accidental system discharge occurs, ventilate work
area before resuming service.
R-134a service equipment or vehicle air conditioner sys-
tems should not be pressure tested or leak tested with
compressed air.
@ some mixtur$ of air and R-134a have been
shown lo b9 combustible rt glgvatad pr€ssur63 and can
resull in tire 01 oxplosion causing inlury ot property
damage. Never uao compre33ed air to pressure t99t R-
134a ssrvico 6quipmsnt or vohicla air conditioner sys-
tems.
Additional health and safety information may be obtained
from the refrigerant and lubricant manufacturers.
'1. Connect a R-134a refrigerant recover/recycling/
charging station to the vehicle, as shown, following
the equipment manufacturer's instructions.
2. lnsert a thermometer in the center vent outlet.
Determine the relative humidity and air tempera-
ture,
Test conditions:
. Avoid direct sunlight.
. Open hood.
. Open front doors.
. Set the temDerature control lever or dial to MAX,
COOL, the mode control switch or dial on VENT
and the recirculation control switch on RECIRCU-
LATE.
. Turn the A,/C switch on. and the heater fan switch
on MAX.
. Run the engine at 1,500 rpm.
. No driver or passengers in vehicle
After running the air conditioning for 10 minutes
under the above test conditions, read the delivery
temperature from the thermometer in the dash vent
and the high and low system pressure from the A,/C
gauges.
Recovery/Rocycling/Charging Station
22-24

l'f .
Electrical
Special Toofs .,....................,23-2
Troubleshooting
Tips and Precautions ..............,.................... . 23-3
Five-step Troubleshooting .............. ......... . . 23-5
wire color codes ..........,23-5
Schematic Symbols ........,................... . . .. .... 23-6
Relay and Control Unit Locations
Engine Compartment ...,..................... ... .. . 23'7
Dashboard ......................23-8
Dashboard/Door ......... 23-12*Airbags ................. ....... Section 24
Air Conditioning ......... Section 21
Aftelnator ..........."""" """ 23-112
Anti-lock Brake System {ABS) Section 19*A/T Gear Position Indicator .....................,. .... ... 23-149
Automatic Transmission Svstem .... . ....... Section 14
Batterv ......... . . . ... ...... .......23-91
Blower controls .. . ... Section 2l
Charging System ....'...........23'112
Connector ldentilication and Wire Harness
Routing .................. ......23'13
Cruise Control ............,........23-240
Dash Lights Brightness Controller ............. ....... 23-180
Fan controfs "" 23'126
Fuel PumD ........ . ........ section 11
Fuses/Refay ...............,..,,.. 23'62
PGM-FI Control System ......................,....... Section 1 1
*Gauges
Circuit Diagram ....,.,.......23-131
Fuef Gauge ...........'.'.......23-142
Gauge/lndicator .. . .. 23-129
Ground Distribution .. . 23-75
Heatei controls .. . ..... Section 21*Horn................. ...............23-196
*tgnition Switch ....................23-89
lgnition System .......,.... 23-102
*lntegrated Control Unit ....................................... 23-156
fnterlock System ,........ . . , ,23-144
Lighting System . . . .. ......... 23-161
Lights, Exterior
Back-up Lights ..'............23'171
Brake Lights .................. 23'174
Daytime Bunning Lights (Canadal ............... 23'166
Front Parking Lights ......,................ .'. .......... 23-167
Front Turn Signal Lights .......... . . ............ ..,.23-167
Headtights ....".'....-... ..... 23'167
High Mount Brake Light ...................... ... .23'179
License Plate Lights ...... 23'176
Taitfights ................ .......23'171
lnterior Lights ..-.......,, . 23-142
Moonroof ..,.................,........ 23-235
Power Distribution ....... . . .23-61
Power Door Locks .......,,,. .23'251
Power Mirrors ,..............,.,...23'206
Power Relays ....... . ...... . . .. 23-86
Power Windows ............,,....23-220
Rear Window Defogger .......................... . . ... . . 23-2OO
Spark Plugs . ..... . ........ .....23-111
Slarting System ................23-93*stereo Sound Svstem ,................. ..... ... . ... ,.,.,,23'147'Supplemental Restraint System (SRS) ... . Section 24
Turn Signal/Hazard Flasher System .......'.'....-... 23-173
*Undel-dash Fuse/Relay Box ............,.................. 23-85
vehicfe soeed sensor (VSSI """" ""' 23-140+Wipers/Washers .........,.,.,...23-214
NOTE: Unless otherwise specified, references to auto-
matic transmission (Mf) in this section include the CVT.

Relay and Control Unit Locations
Engine Compartment
UNDER.HOOD ABS
FUSE/RELAY BOX
CONDENSER FAN
RELAY
UNDER.HOODFUSE/RELAY BOX
MOTORRELAY
A/C COMPRESSORCLUTCH RELAY
RADIATORFAN RELAY
ELD UNIT
t:
tr
tr
uI Il I tl I
23-7

Connector ldentification and Wire Harness Routing
Engine Wire Harness lD16Y5, D16Y8 enginss): '96 - 98 models
Connector or
Torminal
Numbsr of
CavitissLocationConnects toNot€s
c 101c102c103c104c104c105c106c107c108c 109c110c111c112c113c114c115c116cl17c118c119c120cl21
c122c123cl23c124
c125
c127c12Ac129c130c131c132c 133c134c135
c136
c138c139c140c 141c142c 143c144cl44c145c'146cl47
10
1
22
14l4322l0I
2
2
2
2120
3l
14
14
1222
2
2
22
Left side of engine compartmentMiddle of engineMiddle of engineLeft side of engine companmentLeft side of engine compartmentMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of enginefvliddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineLeft side of engine compartmentMiddle of engineMiddle of engineMiddle of engineMiddle of engine
Middle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineRight side of engine companmentBehind right kick panelUnder right side of dashUnder riOht side of dashUnder right side of dashUnder right side of dashUnder right side of dashUnder right side of dash
Under right side of dash
Under right side of dash
Middle of engineMiddle ot enginel iddle of engineMiddle of engineMiddle of ongineMiddle of engineLeft side of engine compartmentMiddle of engineMiddle of engineRight side of engine compartmentRight side of engine compartmentRight side of engine compartment
USACanada
Afi
USA
-' (A/r)
Main wire harness (C303)Crankshaft speed fluctuation (CKF) sensorEngine oil pressure switchAlternatorAlternatorNo. 'l fuel injectorNo. 2 fuel injectorNo.3 fuel injectorNo. 4 fuel injectorIAC valveThrottle position (TP) sensorl\4anifold absolute pressure (MAP) sensorIntake air temperature (lAT) sensorPower steering pressure {PSPI switchEVAP purge control solenoid valveJunction connectorJunction conn€ctorVehicle speed sensor {VSS}Countershaft speed sensorEngine coolant temp€rature (ECT) switch ADistributorEngine coolant temperature (ECT) sendingunrtEngine coolant temperature (ECT) sensorPrimary HO2S (sensor'l)Primary HO2S (sensor 1)Back-up light switchLock-up control solenoid valveSecondary HO2S (sensor 2)Mainshaft speed sensorLinear solgnoid valveShift control solsnoid valveStarter solenoidJunction connectorMain wire harnesE (C446)ECM/PCMPCMECMiPCMECM/PCMMain wire harness (C305)
Main wire harness (C305)
Main wire harness (C305)
Knock sensor (KS)IAC valveVTEC solenoid valveVTEC pressure switchEVAP control canister vent shut valveEGR control solenoid valveSecondary gear shaft speed sensorEGR valveEGR valveDrive pulley speed sensorSolenoid connector {CVT)Driven pulley speed sensor
*, (M/T)M/T*" INT\
*, tAtf)
NT:'96 model*,(A,/T):'97 - 98mooets
moqets
M/T
-1 (l,/T)*, (A,/T)-,(4,/T)*1 {M/T)*, (A,/T)*1 (CW)*, (A,T)
T101r102Left side of engine companmentRight side of engine companmentAlternatorUnder-hood fuse/relay boxG 101Middle of engineEngine ground, via engine wire harness
2
*1: Dl6Y5 engine*2: D16Y8 engine*3: D16Y5 (Ay'T), D16Y8 engines
3-16

Gonnector ldentification and Wire Harness Routing
Engine Wire Harness (D16Y5, Dl6Yg engines): ,99 - 00 models
Connectot or
Terminal
Number ot
CavitiesLocationConn€cts toNotes
c'101cl02c103c104c 104c10s
c107c 108c'r09c110c111cl12c113cl14c l15c116cl17c118c119c120cl20c121
c122c123c123cl23cl24c124c125
c127c12Ac129c 130c131cl32c133c 134c135c137c138c 139c 140c142c143c144cl44c145c146c147
103,]
322223332221414322'10
8,l
2484224222120
32
2212223
282
No. 1 luel injector INo.2 fuel injectorNo.3 fuel injector ]No. 4 fuel injector iIAC valve I anThrottle position lTP) sensorManifold absolute pressure {MAP) sensor IIntake air temperature (lAT) sensor IPower steering pressure (PSP)switch USAEVAP purge control solenoid valve ]
Main wire harness 1C303)Crankshaft speed fluctuation (CKF) sensorEngine oil pressure switchAlternatorAlternator
Left side ot engine compartmentlvliddle of engineMiddle of engineLeft side ot engine compartmentLeft side of engine compartmentMiddle of engineMiddle ot engineMiddle of engineMiddle of engineMiddle oI engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineNliddle of engineMiddle of engineMiddle of engineMiddle of engineRight side of engine compartmentMiddle of engineMiddle of engineN4iddle of engineMiddle of engine
Middle of engineMiddle ot engineMiddle ot engineMiddlo of engineMiddle of engineMiddle ot enginelrliddle of engineMiddle of engineMiddle oI engineMiddle ot engineRight side of engine compartmenlBehind right kick panelUnder right side of dashBehind right kick panelBehind right kick panelBehind righr kick panelBehind right kick panelMiddle ot engine[,liddle of engineN4iddle of engineMiddle of engineMiddle oI engineLeft side of engine compartmentMiddle of engineMiddle of engineRight side ol engine compartmentRight side of engine companmentRight side of engine compartment
USACanada
Junction connectorJUnct|On COnnectorVehicle speed sensor lVSS)Countershaft speed sensorEngine coolant temperature {ECT} switch ADistributorDistributorEngine coolant temperature (ECT) sendingunitEngine coolant temperature (ECT) sensorPrimary H02S (sensor 1)Primary HO2S (sensor 1)Primary HO2S lsensor 1)Back-up light switchLock'!p control solenoid valveSecondary HO2S (sensor 2)Mainshaft speed sensorLinear solenoid valveShift control solenoid valveStarter solenoidJunction connectorMain wire harness (C446)ECM/PCMECM/PCMECM/PCMPCtvtKnock sensor (KS)IAC valveVTEC solenoid valveVTEC pressure switchEGR control solenoid valveSecondary gear shaft speed sensorEGR valveEGR valveDrive pulley speed sensorSolenoid connector (CVT)Driven pulley speed sensor
*' (A/TI
*1 (CVT)*, (M/T)
Mfia (A/Tl
" (A,/T)., (4,/r)-' {AlrJ
*1 (M/T)
tvliT
*1 (CVT)*, (cvT)*' (cw)*1 (MiT)*1 {CVT)*1 {CVT)*, (cvr)
T101T102Left side of engine companmentRight side ot engine companmentAlternatorUnder'hood fuse/relay boxG 101Middle of englne IEngine ground, via engine wire harness*1: 016Y5*2: D16Y8*3: Dl6Y5
engineengine(CW), D16Y8 engines
23-14