1999 HONDA CIVIC ecu connector

Engine RemovaUlnstallation
Removal
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1.
. Make sure iacks and salety stands are placed ploperly
and hoist brackets are attached to the correct posi-
tions on the engine.
. Make sure the vehicle will not roll off stands and fall
while you are working under it.
CAUTION:
. Use fender covers to avoid damaging painted sur-face.
. Unplug the wilin9 connectors caretully while holdingthe conngstor portion to avoid damage,. Mark all wiring and hosos to avoid misconnoction.
Also, be sure that they do not contact other wiring or
hoses or interfere with other parts,
Secure the hood as open as possible.
Disconnect the battery negative terminal first. thenthe positive terminal. Remove the battery.
Remove the strut brace (B'16A2 engine).
8 x 1 .25 mm24 N.m {2.4 kgl.m, 17 lbf.ft}
Disconnect the battery cables from the under-hood
fuse/relay box and battery positive terminal.
STRUT BRACE
UNDER.HOODFUSE/RELAYBOX
BATTERY CABLES
5-2
ECM/PCM
(
5. Remove the battery and battery base.
8 x 1.25 mm24 N.m (2.4 kgf.m, 17 lbf ftl
7.
Disconnect the connectors from the ECM/pCM.
Disconnect the main wire harness connector.
MAIN WIRE HARNESSCONNECTOR

Radiator
Replacement
Drain the engine coolant.
Remove the upper and lower radiator hoses, andATF cooler hoses.
Disconnect the fan motor connector.
Remove the radiator upper bracket, then pull up theraotator,
RADIA
ATF COOLERHOSES (A/T)Refer to sectionwhen installing.
UPPER RAOIATOR HOSE
6x1.0mm7.2 N.m (0.73 kgf.m.5.3 tbf.ft)
1.
2.
3.
5. Remove the fan shroud assemblies and other partsfrom the radiator.
Install the radiator in the reverse order of removal:
NOTE:
. Set the upper and lower cushions securely.. Fill the radiator with engine coolant and bleedthe air.
6x1.0mmCAPY|lT,PS:|" i.i ru- ii b rgr.-,AND CUSHION7.2 tbr.ftl
14
(
I
RESEBVOIR TANK
RADIATOR
LOWER CUSHION
RAOIATOR FAN/SHROUDASSEMBLY
DRAIN PLUGO-RINGReplace.
LOWER RAOIATOR HOSE
ATF COOLERPIPES {A/T)
,iiiiii
10-6

3.
5.
6.
1.
Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors is cut off to improve fuel economy at
speeds over the following rpm:. D16Y5 engine (M/T):850 rpm. D]6Y5 engine (CVT), D'16Y8 engine (USA M/T): 920 rpm
. Dl6Y8 engine (USA A,/I), D16Y7 engine (USA A,/T);910 rpm
. D16Y8 engine (Canada M/T), D16Y7 engine (canada): 990 rpm
' D16Y8 engine (Canada M/T): 1,000 rpm
. 816A2 engine: 970 rpm
. Fuel cut-off action also takes place when engine speed exceeds 6,900 rpm (D16Y5, D16Y7 engine; D'16Y8 engine:
7,000 rpm. 816A2 engine: 8.100 rpm), regardless of the position of the throttle valve, to protect the engine from
over-rewing. With '99 Dl6Y7 engine (A,/T) and '99 D16Y8 engine (A./T), the PCM cuts the fuel at engine speeds over
5,000 rpm when the vehicle is not moving.
IVC Compressor Clutch Relay
When the ECM/PCM receives a demand for cooling from the air conditioning system, it delays the compressor from
being energized, and enriches the mixture to assure smooth transition to the A,/C mode
Evaporative Emission (EVAP) Purge Control Solenoid Valve*'
When the engine coolant temperature is above 154'F (68'C). the ECM/PCM controls the EVAP purge control solenoid
valve which controls vacuum to the EVAP purge control canister.
Evaporative Emission (EVAP) Purge Control Solenoid Valve*a
When the engine coolant temperature above 154"F (68"C), intake air temperature above 32"F (0'C) and vehicle speed
above 0 mile (0 km/h) or [Ay'C compressor clutch on and intake air temperature above 160"F (41'C)], the ECM/PCM
controls the EVAP purge control solenoid valve which controls vacuum to the EVAP purge control canister.
Exhaust Gas Recirculation (EGR) Control Solenoid Valve*?
When EGR is required for control of oxides of nitrogen (NOx) emissions. the ECM controls the EGR control solenoid
valve which supplies regulated vacuum to the EGR valve
Alternator Control
The system controls the voltage generated at the alternator in accordance with the electrical load and driving mode,
which reduces the engine load to improve the fuel economy.
ECM/PCM Fail-safe/Back-up Functions
1. Fail safe Function
When an abnormality occurs in a signal from a sensor, the ECM/PCM ignores that signal and assumes a pre-pro-
grammed value for that sensor that allows the engine to continue to run.
2. Back-uD Function
When an abnormality occurs in the ECM/PCM itself, the fuel injectors are controlled by a back-up circuit independent
of the system in order to permit minimal driving.
3. Self diagnosis Function lMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the lvllL and stores the DTC
in erasable memory. When the ignition is initially turned on, the ECM/PCM supplies ground for the MIL for two sec-
onds to check the MIL bulb condition.
4. Two Trip Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S, fuel metering-related. idle control
system, ECT sensor, EGR system and EVAP control system self-diagnostic functions. When an abnormality occurs,
the ECM/PCM stores it in its memory. When the same abnormality recurs after the ignition switch is turned OFF and
ON 0l) again, the ECM/PCM informs the driver by lighting the MlL. However, to ease troubleshooting, this function is
cancelled when you jump the service check connector. The MIL will then blink immediately when an abnormality
occurs,
5. Two (or Three) Driving Cycle Detection Method
A "Driving Cycle" consists ot starting the engine. beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions is detected during two consecutive driving cycles, or TWC deterioration is detected dur-
ing three consecutive driving cycles, the ECM/PCM turns the MIL on. However, to ease troubleshooting, this function
is cancelled when you jump the service check connector. The MIL will then blink immediately when an abnormality
occurs.
(cont'd)
1 1-1 05
.1.

I
L
1D16Y5, D16Y8 engine with M/T 81642 engine)I
D16Y7 engine:
{From page 11-192)
Check the IAC valve:Disconnect the 3P connector from
the IAC valve.
Check the IAC valve:Disconnect the 2P connectorfrom the IAC valve.
Does the engine speed drop or
the engine stall?
Adiust the {base} idle speod (see
page 11-220 - 2231.It it's impos-
aible, clean the ports in lhe throt'
tle bodv,
(From page 11-192i
Check Ior vacuum leaks:1. Turn the ignition switch OFF.2. Remove the intake air ductfrom the throttle body.
3. Start the engine and let it idle.
4. Put your finger on the lowerpon in the th.ottle body.
Ch€ck tor vecuum loaks, m.kesure the throttle valve is com_pletaly closed, end repair as nec-Does the engine speed droP?
Adiust the idle speed (see page
11-220 - 2231. lf it's impossible,
reolace the IAC velve.UPPERPORT
1 1-1 93

t
Belore connecting a new fuel tube/quick-connect fining
assembly, remove the old retainer from the mating pipe
with thetabs pulled
apan, removeand discard the
I
retarner
New FUEL TUBE/OUICK.CONNECTFITTING ASSEMELY
3. Align the quick-connect fiftings with the pipe, and
align the retainer locking pawls with the connector
grooves. Then press the quick-connect fittings onto
the pipe until both retainer pawls lock with a click-
ing sound.
NOTE: lf it is hard to connect, put a small amount
of new engine oil on the pipe end.
Connection with new retainer:
4. Make sure the connection is secure and the pawls
are firmly locked into place; check visually and by
pulling the connector.
RCTAINER
Reconnect the battery negative cable, and turn the
ignition switch ON (ll). The fuel pump will run for
about two seconds, and fuel pressure will rise.
Repeat two or three times, and check that there is
no leakage in the fuel supplv system
11-229

Lock-up Gontrol Solenoid Valve A/B Assembly
Test
'1, Disconnect the 2P connector from the
trol solenoid valve 1y'8 assembly.
TERMINAL SIOE OF
MALE TERMINALS
tocK-up con-
LOCK.UP CONTROLSOLENOID VALVE A/BASSEMBLY
Measure the resistance between the No. 2 terminal
(solenoid valve A) of the lock-up control solenoid
valve connector and body ground, and between the
No. 1 terminal (solenoid valve Bl and body ground.
STANDARD: 12 - 25 O
Replace the lock-up control solenoid valve assem-
bly if the resistance is out of specification.
lf the resistance is within the standard, connect the
No. 1 terminal of the lock-up control solenoid valve
connector to the battery positive terminal. A clicking
sound should be heard. Connsct the No. 2 terminal to
the battery positive terminal. A clicking sound should
be heard. Replace the lock-up control solenoid valve
assembly if no clicking sound is heard.
Replacement
NOTE: Lock-up control solenoid valves A and I must bs
removed/replaced as an assembly.
1. Remove the mounting bolts and lock-up control
solenoid valve Ay'B assemblv.
6 r 1.0 mm12 N.m (1.2 kgf.m,8.7 lbl.ftl
/:'-
Clean the mounting surfaceand fluid psssages.
Clean the mounting surface and fluid passages of
th6 lock-up control solenoid valve assembly, and
instsll a new lock-up control sol€noid valve Ay'B with
a new filtsr/gask€t.
Check the connector for rust, dirt or oil, and racon-
nect it securely.
1+105

Shift Control Solenoid Valve A/B Assembly
Test
1. Disconnect the 2P connector from the shift control
solenoid valve A,/B assemblv.
SHIFT CONTROLSOLENOID VALVE A/B
ASSEMBLY
N4easure the resistance between the No. 1 terminal(solenoid valve A) of the shift control solenoid valve
connector and body ground, and between the No. 2
terminal (solenoid valve B) and body ground.
STANDARD: 12 - 25 O
Replace the shift control solenoid valve assembly if
the resistance is out of specification,
lf the resistance is within the standard, connect the
No. 1 te.minal of the shift control solenoid valve
connector to the battery positive terminal. A clicking
sound should be heard. Connect the No. 2 terminal
to the battery positive terminal. A clicking sound
should be heard. Replace the shift control solenoid
valve assembly if no clicking sound is heard.
14-106
Replacement
NOTE: Shift control solenoid valves A and B must be
removed/replaced as an assembly.
1. Remove the mounting bolts and shift control solenoid
valve A,/B assembly.
5xL0mm12 N.m(1.2 kgf.m,8.7 lbf.ft)CONNECTOR BRACKET
FILTER/GASKETBeplace.Clean the mounting surfaceand fluid passages.
Clean the mounting surface and fluid passages of
the shift control solenoid valve assembly, and
install a new shift control solenoid valve Ay'B with a
new filter/gasket and the clamp bracket.
Check the connector for rust. dirt or oil. and recon-
nect it securelv,

Mai nshaft/Cou ntershaft
Linear Solenoid AssemblySpeed Sensors
Replacement
1. Remove the mounting bolts and the linear solenoid
assemory.
Clean the mounting surfaceand flu id passages.
6x1.0mm12 N.m 11.2 kgl m,8.7 tbf.ftl
@
@
GASKET
Clean the mounting surface and fluid passage of the
linear solenoid assembly and transmission housing.
Install a new linear solenoid assembly with a new
gasl(et.
NOTE; Do not pinch the gasket when installing the
linear solenoid; make sure that the gasket is installedproperly in the mounting groove of the linear sole-
noid.
Check the linear solenoid connector for rust, dirt or
oil, and connect it securely,
LINEARSOLENOIDASSEMELY
I
14-108
Replacement
't.
6x128.7
Remove the 6 mm bolt and the countershaft speed
sensor from the right side cover.
COUNTERSI{AFTSPEED SENSOR
O.RINGReplace.
MAINSHAFTSPEEDSENSOR
MAINSHAFT SPEEDSENSOB WAS}IER(D16Y7 enginel
6x1.0mm12 N.m (1.2 kgf m,8.7 tbf.ft)
1.0 mmN.m (1.2 kgf.m,rbf ft)
\\
/,
%/E:)
Remove the 6 mm bolt and the mainshaft sDeed
sensor from the transmission housino.
Replace the O-ring with a new one before installing
the countershaft speed sensor or th€ mainshaft speed
sensor.
NOTE: Installthe mainshaft speed sensor washer on
the mainshaft speed sensor. The mainshaft speed
sensor washer is used on models with the D'|6Y7
engine.