1996 HONDA CIVIC PCM

-'
GAUGEASSEMALY
DRIVE PULLEYSPEED SENSOR
ORIVEN PULLEYSPEED SENSOR
SECONOARYGEAB SHAFTSPEED SENSOR
SOLENOID
To INTERLOCK CONIBOL UNIT
*l : USA model
*2: a/T(D16Y/, D16Y8 engine)
,.3: CW(016Y5 engine)
*4: A/T and D16W engine
*5: Except A/T and Dl5Y7 engine
*6: Cw(Dl6Y5 engine), Dl5Y8 engine and 816A2 engine
(cont'd)
11-41
EcM/PcMA(32P)EcM/PcMB(25P)
7II1011
t41617181920121222324
ECM/PCMC(31P)ECM/PCMD(I6P)
I
TERMINAL LOCATIONS

(O16Y5, Dl6Y8.nlin.3llOl6Y?.ngir.l
ct33.r tFcM-B)C134 {EC[r,l/FCMal
cr35lEcM/PCM-D)
NOTE: e
f'Tfl'n
I-IBLffiHJ-IltlcRr'r/wlr l]l
l-''lwHtREcp -l
liELx/wNr' --l
ca3l
ffi
Tttr-Ei ---
FltEtstK ll
FfwNr/RED''_llTltHr/BL( l
ffi
@
F Irt
Irli I
tilwHT,"Ed-l| . lcFMMr I11 BLX^VHT' I11 B!x.^rHr I
Different wires with the same color have been given a number suffix to distinguish them (for example, YEUBLKT
and YEUBLK' are not the same).
O: Related to Fuel and Emissions System
- Connector with male terminals (double outline): View from terminal side
- Connector with female terminals (single outline): View from wire side
c t32 {ECt/r/pcM-a)
26E9l0tl
12t3l/a'tst6171El92024
25212a2930
c{t3
l.7
9rolrt12t3
I2al589t0
l!121317t8l9
11-63

c130
I10
l112131,4t5ta11t8t9
ct3r
1lz3lt/X61789to
cr34 tEcM/PCM-C)cr35 lPCM-Dr:cr35lPcl|.D,€
ca32
lr 2 3.1
IiGTNiBN Ill
l5l-wxr,nol]ll:a BLX vHI I
NOTE; . Different wires with the same color have been given a number suffix to distinguish them (for example, YEUBLK1
and YEUBLK, are not the samel.
O: Related to Fuel and Emissions Svstem.- Connector with male terminals (double outline): View from terminal side
- Connector with female terminals (single outline): View from wire side
lrl2l
lll* -_-l
tn Bs I
c1a
lr 2l
f.fil
,bl onrrwlrl.lftlBLrwHri-Flirx,lvHJ l]-l
c,|52 tEcM/PCM-Al
\-a
't/3l-1.51
/tgto 'lt12l3
2at6IE e t|0111'12ItItIt[l
11-79

Troubleshooting
Troubleshooting Procedures
How To Begin Troubleshooting
When the Malfunction Indicator Lamp (MlL) has been reported on, or there is a driveability problem, use the appropr'-
ate orocedure below to diagnose and repair the problem'
A. When the MIL has come on:
,1. connect the Honda PGM Tester or an oBD ll scan tool to the 16P Data Link connector (DLC) located near the left
kick panel.
2. Turn the ignition switch ON (ll)
3. Check the DTC and note it. Also check and note
the freeze trame data
Refer to the Diagnostic Trouble Code Chart and
begin troubleshooting.
NOTE:
.SeetheoBD||scantoolorHondaPGMTesteruser,smanua|sforspecificoperatinginstructions..
.Thescantoo|oltestercanreadtheDiagnosticTroub|ecodes(DTc},freezeframedata,currentdata,andother
Engine Control Module (ECM)/Powertrain Control Module (PCM) data'
oFreezeframedataindicatestheengineconditionswhenthefirstma|function,misfireorfue|trimma|function
was detected. lt can be useful information when troubleshooting'
B. When the MIL has not come on , out there is a d riveability problem, refer to the Symptom Chart on page 1 1-84'
c.DTcswi|lbeindicatedbytheb|inkingoftheMa|function|ndicatorLamp(M|L)withthescsserviceconnectorcon.
nected.
Connect the SCS service connector to Service Check Connector as shown (The 2P Service Check Connector is
|ocatedunderthedashonthepassenger,ssideofthevehic|e')TurntheignitionswitchoN{||)'
OBO ll SCAN TOOL olHONOA PGM TESTER
SERVICE CHECKCONNECTOR I2P)
scs sERvlcE(cont'd)
MALFUNCTIONINDICATORLAMP
DATA LINK CONNECTOR Il6PI
07PAZ - (x)l0100
11-81

Troubleshooting
Troubleshooting Procedures (cont,dl
ll, Engine Control Module (ECM)/powertrain Control Module (pCM) Reset procedure
NoTE: Resetting the EcM/PcM will erase any stored DTcs and any freeze data. lt will also restart all readiness codemonitors.
Either of the following actions will reset the ECM/PCM.
. Use the OBD ll scan tool or Honda pGM Tester to clear the EClM,s/pCM,s memory.
NorE: see the oBD ll scan tool or Honda PGM Tester user's manuals for specific operating instructions.
' Turn the ignition switch oFF. Remove the BACK uP (7.5 A) fuse from the under-hood fuse/relay box for 10 sec-onds.
NorE: Bemoving the BACK uP (7 5 A) fuse cancels the clock and the radio presets. Make note of the customer,spresets so you can reset then
lll. Final Procedure (this procedure must be done after any troubleshoottng)
1. Remove the SCS Service Connector if it is connected.
NoTE: If the Scs service connector is connected and there are no DTcs stored in the EcMipcM, the MtL will stayon when the ignition switch is turned ON 0l).
2. Do the ECM/PCM Reset procedure.
3. Turn the ignition switch OFF.
1-82

lf the inspection for a particular code requires voltage or resistance checks at the ECM/PCM connectors, remove the right
kick panel. Pull the carpet back to expose the ECM/PCM. Remove the ABS control unit if so equipped. unbolt the EcM/
PCM bolt. Turn the ignition switch oFF, and connect the backprobe sets and a digital multimeter as described below
check the system according to the procedure described for the appropriate code(s) listed on the following pages'
The illustrationshows '96 - '98 models.
How to Use lhe Backprobe Sets
connect the backprobe adapters to the stacking patch cords, and connect the cords to a multimeter. using the wire insula-
tion as a guide for the contoured trp of the backprobe adapter. gently slide the tip into the connector from the wire side
until it comes in contact with terminal end of the wire'
BackProbe
BACKPROEE SET
07SAZ - 001000A lTwo
DIGITAL MULTIMETER(Commercially avail.bleI orKs - AHM - 32 - oo3 (cont'd)
KICK PANEL
1 1-83

Troubleshooting
Troubleshooting Procedures (cont,dl
ECM/PCM Data
By connecting the OBD ll scan tool or the Honda pGM Tester to the l6p data link connector (DLC), various data can beretrieved from the EcM/PcM. The items Iisted in the table below conform to the sAE recommended practice.The Honda PGM Tester also reads data beyond that recommended bv SAE.understanding this data wil help to find the causes of intermittent fairures or engine probrems,
NOTE:
' The "operating values" given below are approximate values and may be different depending on the environment andthe individual vehicle.. Unless noted otherwise, "at idle speed,, means idling with the engine completely warmed up, Ay'T in position @ or E],M/T in neutral, and the Ay'C and all accessories turned off.
(
DataDescriptionOperating ValueFreeze Data
Diagnostic
Trouble Code(DTC)
lf the ECM /PCM detects a problem, it will store it as acode consisting of one letter and four numbers.Depending on the problem, an SAE-defined code (poxxx)or a Honda-defined code (Plxxx) will be outDut to therester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECM/PCM computes engine speed from the signalssent from the Crankshaft Position sensor.This data is used for determining the time and amount offuel injection,
Nearly the same as
tachometer indication.YES
Vehicle SpeedThe ECM/PCM converts pulse signals from the VehicleSpeed Sensor (VSS) into speed data.Nearly the same as
speedometer indicationYES
Manifold
Absolute
Pressure {MAP)
The absolute pressure caused in the intake manifold bvengine load and speed.With engine stopped:
Nearly the same as atmo-
spheflc pressure
At idle speed:
24 - 31 kPa (180 - 280
mmHg, 7.1 - 11.0 inHg)
YES
Engine Coolant
Temperature
(ECT)
The ECT sensor converts coolant temperature into volt_age and signals the ECM/PCM. The sensor is a thermistorwhose internal resistance changes with coolant temDera_ture. The ECM/PCM uses the voltage signals from theECT sensor to determine the amount of iniected fuel.
With cold engine:
Same as ambient temper,
ature and IAT
With engine warmed up:
176 - 194.F (80 - 90.C)
YES
Heated Oxygen
Sensor {HO2S)(Primary,
Sensor 1)(Secondary
Sensor 2)
The Heated Oxygen Sensor detects the oxygen contentin the exhaust gas and sends voltage signals to theECI\4/PCM. Based on these signats, the ECM/pCM con_trols the airlfuel ratio. When the oxygen content is high(that is, when the ratio is leaner than the stoichiometricratio), the voltage signal is lower.When the oxygen content is low (that is, when the ratiois richer than the stoichiometric ratio), the voltage signalis higher.
0.0 - 1.25 V
At idle speed:
about 0.1 - 0.9 V
NO(Sensor 1)
1 1-86

DataDescriotion
Loop status is indicated as "open" or "closed"'
Closed: Based on the HO2S output, the ECM/PCM deter-
mines the airlfuel ratio and controls the amount of inject-
ed fuel.
Open: lgnoring HO2S output, the ECM/PCM refers to sig-
nals from the TP, MAP, and ECT sensors to control the
amount of injected fuel.
The air/fuel ratio correction coefficient for correcting the
amount ot injected fuel when H02S feedback is in the
closed loop status When the signal from the HO2S is
weak, short term fuel trim gets higher, and the ECM/PCM
increases the amount of injected fuel The airlfuel ratio
gradually gets richer, causing a higher HO2S output
Consequently, the short term fuel trim is lowered, and
the ECMiPCM reduces the amount of injected fuel
This cvcle keeps the airlfuel ratio close to the stoichio-
metric ratio when in closed loop status'
Operating ValueF eeza Data
HO2S
Feedback
Loop Status
At idle speed: closed
YES
Short Term
Fuel Trim
! 20%
YES
Long Term
Fuel Trim
Long term fuel trim is computed from shon term fuel
trim and indicates changes occurring in the fuel supply
svstem over a long Period
lf long term fuel trim is higher than 1.00, the amount of
injecGd fuel must be increased. lf it is lower than 1 00'
the amount of injected fuel must be reduced'
! 20%
YES
lntake Air
Temperature
{IAT)
The IAT sensor converts intake air temperature into volt-
age and signals the ECM/PCM. When intake air tempera-
ture is low, the internal resistance of the sensor
increases. and the voltaqe signal is higher'
With cold engine:
Same as ambient temPer'
ature and ECTYES
At idle speed:
approx. 10 %YESThrottle
Position
Based on the accelerator pedal position, the open'ng
angle of the throttle valve is indicated
lgnition
Timing
lgnition timing is the ignition advance angle set by the
gCV/eCV. tn" gCU/PCM matches ignition timing to the
driving conditions.
CLV is the engine load calculated from the MAP data'
At idle speed: 12'i 2'
(81642 engine: 16" t 2")
BTDC with the SCS ser-
vice connector connected.
NO
Calculated
Load Value
{CLV)
At idle speed:
15-35%
At 2.500 rpm with no load:
12 - 30%
YES
ro
11-87