Oil Pressure
Testing
lf the oil pressure warning light stays on with the enginerunning, check the engine oil level. It the oil level iscorrect:
Connect a tachometer.
Remove the oil pressure switch and install an oil pressure gauge.
Start the engine. Shut it off immediately if the gaugeregasters no oil pressure. Repair the problem beforecontinuing.
Allow the engine to reach operating temperature (fan
comes on at least twicel. The pressure should be:
Engine Oil Pressure:
At ldle: 70 kPa {O.7 kgficmr, tO psil
minimum
At 3,OOO rpm: 34O kPa (3.5 kgf/cmr, 50 psil
minimum
a lf oilpressure is within specifications, replace theengine oil pressure switch and recheck.
a lf oil pressure is NOT within specifications,rnspect the oil pump (see page g-11).
l
2.
Oil Jet
lnspection(818C1, 818C5 engines
only)
1. Remove the oil jet (see pages 8 4 or 8 5) and inspectit as follows.
a Make sure rhat a 1 .1 mm (O.04 in) diameter drillwillgo through the nozzle hole fl.2 mm (O.O5 in)diameter).
a Insert the other end of the same 1 .1 mm {0.O4in) drill into the oit intake (1.2 mm (0.05 in)diameter).
Make sure the check ball moves smoothly and hasa stroke of approximately 4.0 mm (O.16 in).a Check the oil jet operation with an air nozzle. ltshould take at least 2OO kPa 12.O kg|lcm2, 2gpsi) to unseat the check ball.
NOTE: Replace the oiljet assembly if the nozzleis damaged or bent.
2. Mounting torque is critical. Be very precise when in-stalling.
Torque: 16 N.m (1.6 kgf.m, 12 lbf.ftl
1.2 mm (0.05 inl
16 N.m {1.6 kgf'm, 12 lbf.ftl
8-9
8.Mix the recommended antifreeze with an equal
amount of water in a clean container.
NOTE:
a Use only genuine Honda antifreeze/coolant.
a For best corrosion protection, the coolant concen-
tration must be maintained year-round at 500,6
minimum. Coolant concentrations less than 507o
may not provide sufficient protection against cor,
rosion or freezing.
a Coolant concentrations greater than 60% will im-
pair cooling efliciency and are not recommended.
CAUTION:
a Do not mix different brands of anti-lrcezel
coolants.
a Do not use additional rust inhibitots or anti-tustproducts; they may not be compatible with the
coolant.
Engine Coolant Refill Capacity [including reservoir
{0.6 { (0.6 US qt, 0.5 lmp qr)ll:
81881 engine:
Ml7:1-1t {/t.6 US qt. 3.9 lmp qtl
818B1, 818C1 engin€s:
AlTt 1.7 | 15.0 US qt, 4.1 lmp qt)
818C1, B18C5 engines:
MlTt 1.7 t 15.0 US $, 4.1 lmp qtl
FILLER NECK
9.Pour coolant into the radiator up to the base of the
tiller neck.
10. Startthe engine and let jt run until itwarmsup(the
radiator fan comes on at least twice).
1 1 . Turn olf the engine. Check the level in the radiator,
add coolant if needed.
'12. Put the radiator cap on tightly, then run the engine
again and check for leaks.
10-7
Inspection
Remove the timing belt (81881 engine: see page 6-10, B'l8Cl,818C5 engines: see page 6-48).
Tu.n the water pump pulley counterclockwise.Check that it turn freely.
Check for sign6 of seal leakage.
NOTE: A small amount of "weeping" trom thebleed hole is normal.
BLEED HOLE
Remove the timing belt (81881 engine: see page 6-
10,818C1, Bl8C5 engines: see page 6-48).
Remove the camshaft pulleys and the back cover(B'1881 engine: see page 6-20, 818C1, 818C5
engines: see page 6-60).
Remove the water pump by removing flve bolts.
NOTE: Inspect, repair and clean the O-ring groove
and mating surface with the cylinder block,
Replacement
6 x 1.0 mm12 N.m 11.2 kgt.m,8.7 tbf.tt)
4. Install the water pump in the reverse order ofremoval.
a Keep the O-ring in position when installing.a Clean the spilled engine coolant.
BLEED HOL€
10-1 1
ECM Data
By connecting the OBD ll scan tool or the Honda PGM Tester to the 16P data link connector (DLC), various data can beretrieved from the EcM The items risted in the tabre berow conform to the sAE recommended practice.The Honda PGM Tester also reads data beyond that recommended bv SAE.understanding this data wirl herp to rind the causes of intermiftent fairures or engine probrems.
NOTE:
' The "operatlng values" given below are approximate values and may be different depending on the environment andthe individual car.' Unless noted otherwise, "at idle speed" means idling with the engiFe completely warmed up, transmissron in park orneutral and the A,/C and all accessories turned off.
DataDescriptionOperating ValueFreeze Data
Diagnostic
Trouble Code(DTC)
lf the ECM detects a problem, it will store tt as a cocteconsisting ot one letter and four numbers.Depending on the problem, an SAE-defined code{Poxxx) or a Honda-defined code (plxxx) will beoutput to the lester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECM computes engine speed from the signalssent from the Crankshaft Position sensor.This data is used for determining the I|me andamount of fuel injection.
Nearly the same as
tachometer indication at
idle speed:
81881,818C1 engines:
750 t 50 rpm
818C5 engine:
800 1 50 rpm
YES
Vehicle SpeedThe ECM converts pulse signals trom the VehicleSpeed Sensor (VSS) into speed data.
Nearly the same as
speedometer indicationYES
Manitold
Absolute
Pressure {MAP)
The absolute pressure created in the intake manifoldby engine load and speed.With engine stopped:
Nearly the same as atmo
spheric pressure. At idle
speed:
24 - 37 kPa (180 - 280
mmHg,7.1 1'1.0 inHg)
YES
Engine Coolant
Temperature
(ECT)
The ECT sensor converts coolant temperature intovoltage and signals the ECM. The sensor is a thermis-tor whose internal resistance changes with coolanttemperature. The ECM uses the voltage signals fromlhe ECT sensor to determine the amount of iniectedfuel.
With cold engine:
Same as ambient temper
ature and IAT
With engine warmed up:
approx. 176 - 200'F
{80 - 93.C)
, YES
Heated Oxygen
Sensor (HO2S)
{sensor 1)(sensor 2)
The Heated Oxygen Sensor detects the oxygen con-tent in the exhaust gas and sends voltage signals tothe ECM. Based on these signals,lhe ECM controlsthe airlfuel ratio. When the oxygen content is high{that is, when the ratio is leaner than the stoichiomericratio), the voltage signal is lower. When the oxygencontent is low (that is, when the ratio is richer thanthe stoichiomeric ratio), the voltage signal is higher.
0.0 - 1.25 V
At idle speed:
abour 0.'1 - 0.9 V(sensor I )NO(sensor 1)
(conl'd)
11-37
Troubleshooting
DataDescriotionOperating ValueFreeze Data
HO25
Feedback
Loop Status
Loop status is indicated as "open" or "closed".
Closed: Based on the H02S output, the ECM deter-
mines the airlfuel ratio and controis the amount of
iniected fuel.
Open: lgnoring HO2S output, the ECM refers to sig-
nals from the TP, MAP, and ECT sensors to control
the amount of iniected fuel.
Al idle speed: closed
YES
Short Term
Fuel Trim
The airlfuel ratio correclion coeificient lor correcting
the amount ol iniected fuel when HO2S feedback is in
the closed loop status. When the signal from the
HO2S is weak, short term fuel trim gets highef. and
the ECM increases the amount of injected fuel The
airlfuel ratio gradually gets richer, causing a higher
HO2S output.
Consequentlv, the short term fuel trim is lowered, and
the ECM reduces the amount of injected tuel. This
cycle keeps the airlfuel ratio close to the stoichiomeric
ratio when in closed loop status.
-30o/" - + 41%
YES
Term
Trim
Long
F uel
Long term fuel trim in computed trom short term fuel
trim and indicates changes occurring in the fuel sup-
ply system over a long period.
lf long term fuel trim is higher than 1.00, the amou nt
of injected fuel must be increased. ll it is lower than
1.00, the amount of iniected fuel must be reduced
-14% - + 2Oo/"
YES
lntake Air
Temperature(rAT)
The IAT sensor converts intake air temperature into
voltage and signals the ECM. When intake air temper-
ature is low, the internal resistance of the sensor
increases, and the voltage signal is higher.
With cold engine:
Same as ambient temPer-
ature and ECTYES
Throttle
Position
Based on the accelerator pedal position. the opening
anole of the throttle valve is indicated.
Ar idle: Approx. 107o
At full throttle: Approx.
90%
YES
lgnition
Timing
The ignition advance angle is set by the ECM. The
EClvl matches ignition timing to the driving condi-
tio ns.
At idle speed: 16 t 2'
BTDC with the SCS ser-
vice connector connected.
NO
Calculated
Load Value
(CLV)
CLV is the engine load calculated from the MAP data.At idle speedi
15 - 35%
At 2,500 rpm with no load:
12 - 30./.
YES
-38
PGM-FI System
Random Misfire
1T0-500 1 a nd Fo-30ittrrousFF0304-lThB scan tool indicates Diagnostic Trouble Code {DTC) P0300 and some of
P0301 - P0304: Random misfire.
Doscription
Misfir; detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluciuation sensor which
is attached to the crankshsft.
lf misfiring strong enough to damage the catalyst is detected, the MIL will blink during iho time of its occurrence, and DTC
p0300 and some of DTCS p0301 through P0304 will be stor€d. Then, after misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTC
PO3O0 and some ot DTCS P0301 through P0304 will be stored
NOTE: lJ some of the DTCS listed below are stored at the same time as a misfire DTC, troubleshoot those DTCS first. then
troubleshoot the misfire DTC.
P0171, P0172: Fuel metering
P0505: ldle Control SYstem
P1361, P1362: TDC sensor
P1381. P1382: CYP sensor
P1508: IAC valve
Possible Cause
. Fuel pump insufficient fuel pressure. amount of flow
. Fuel line clogging, blockage, leakage
. Fuel {ilter clogging
a Fuel pressure regulator stuck open
. Distributormallunction
o lgnition coil wire open, leakage
. lgnition control module malfunction
. Valves carbon deposit
a Compression low
. IAC valve malfunction
. Fast idle thermo valve malfunction
o Fuel does not meet Owner's Manual spec., lackotfu€l
. VTEC system malfunction
Troubleshooting
By test-driving, determine the conditions during which misfire occurs. Depending on these conditions, test in the order
described in the table below.
Fuel
pressure
Distributor
and lgnition
wires
tcMIAC ValveValve
Clearance
wEc
System
11118section 23section 231 1- 100section 6section 6
Only low rpm and
loao@o@@
Only acceleratingo@o
Only high rpm and
loado@@@o
Not specificationo@@@@
NOTE: lf misfire doesn't recur, some possible causes arefuel that doesn't meet owner's manual spec, lackoffuel, carbon
deposits on spark plug, etc.
11-78
ldle Control System
System Description
The idle speed of the engine is controlled by the ldle Air Control (lAC) V8lve.
The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled by the
ECM. When the IAC Valve is activated. the valve opens to maintain the proper idle speed.
81881 engine {B18Cl, B18C5 engines are similarl:
YELI - F.om PGM'FIBLK - MAIN RELAY
VARIOUS SENSORS
L
1 1-96
2.
1.
1.
2.
After the engine stans, the IAC valve opens for a certain time. The amount ol air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is low, 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.
IDLE SPEEDtrpm,
ENGINECOOLANT TEMPERATURE
140
50
104
40
-1 32
-20 0
176 ('F)
80 fcl
When the idle speed is out of specification and the scan tool does not indicate Diagnostic Trouble Code (DTC) P0505
or P'1508, check the following items:. Adiust the idle speed (see page '11-111)
' ALT FR signal (see page 11-101). Air conditioning signal {seepage'11-102)' Brake switch signal (seepagell-104)
. Starter switch signal (see page 11-1051. A,4 gear position signal (see page 1l 106) (A"/T)
. PSP switch signal (see page 11-108) (USA)
. Fast idle thermo valve (see page 11-110). Hoses and connections. IAC valve and its mounting O rings
ll the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 'l I -1 1 l).
lf the idle speed still cannot be adjusted to specification (and the scan tool does not indicate DTC P0505 or P1508) after
IAC valve replacement, substitute a known-good ECM and recheck. lf symptom goes away, replace the original ECM.
11-97