P0505 HONDA CIVIC 1996 6.G Workshop Manual

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*:The E indicator light and the Maltunction Indicator Lamp (MlL) may come on simultaneously.*1: D16Y5 engine (CVT)"5: '96 D16Y5 engine, D16Y7 engine, D16Y8 engine (sedan).'97 D16Y5 engine, Dl6Y7 engine (coupe: KA, KC models, sedan: KA.
KC, KL (DX) models, hatchback: all models), D16Yg engjne (sedan: KA, KC models)*6: '96 D16Y8 engine (coupe),'97 Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model),'97 D'16Y8 engine (coupe: all models,
sedan: KL model),'98-all models,'99-all models,'00-all models*12: Except A,,/T (D16Y7, D16Y8 enginei*13: A"/T (D16Y7, D16Y8 engine)!l*14:'97 model*16:'98 model" 17: '99 - 00 models
(cont'd)
1 1-99
DTC{MlL indication}Detoction lt€mProbable C.usePage
P0441*5 (92)
Evaporative Emission ControlSystem InsufficientPurge Flow
EVAP Purge Control Solenoid VaiveOpen or short in EVAP Purge Control
Solenoid Valve circuitEVAP Control CanisterVacuum linesECM/PCM
11-271
P0451'11 (91)FuelTank Pressure Sonsor CircuitRange/Parformance
. FuelTank Pressure Sensor' ECM/PCM11 274
P0452{6(9r )
Fuel Tank Pressure Sensor CircuitLow Input
Short in FuelTank Pressure Sensor circuatFuel Tank Pres$ure SensorECM/PCM
11-275
P0453*6 {91)
Fuel Tank Pressure Sensor Circuit
High Input
ODen in Fuel Tank Pressure Sensor circuit
Fuel Tank Pressure Sensor
ECM/PCM
11-219
P0500*1, (17)Vehicle SpeedSensor CircuitMalfunction
V€hicle Speed SensorVehicle Speed Sensor circuit
ECM
11-176
P0501*'3 l17l
Vehicle SpeedSensor CircuitRange/Performance
V€hicle Sp€ed SensorVehicle Speed Sensor circuitPCM
r 1- 176
P0505 (14)ldle Control Systemlvl a lfu n ctio n
. IAC valve. Throttle Body11-192
P0700*r3and some ofP0715P0720P0730 (70)*
P0740P0753P0758
AutomaticTransaxle
Section 14
P0700*1and (70)*
P0725
Automatic TransaxleSection 14
(13)Barometric PressureCircuitRange/Performance Problem
. ECM/PCM (Baro sensor)1 1-178
P1107 (13)BarometricPressure CircuitLow Input
. ECM/?CM (Baro s€nsor)11-178
P1108 (13)BarometricPressure CircuitHigh Input
. ECM/PCM lBaro sensor)1 1-178
P1121*'. *16. *'? \71Throttle Position Lower ThanExpected
. I r sensor11-138
P1122'14.*16.*n 17lThrottle Position Higher ThanExpected
. TP sensor11-'138
15)Manifold Absolute PressureLower Than Expected
. MAP sensor1 1'123
P1129*1r.*16.*"(5)Manifold Absolute PressureHigher Than Expected
. MAP sensor't1-123

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected. the MIL will blink during the time of its occurrence, and DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through P0304 will be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC. troubleshoot those DTCS first, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304

1.After the engine starts, the lAc valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is tow, 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'
IOLE SPEED
lrpml
176
80
ENGI ECOOLANI TEMPERATURE
t" Fl
toc)
ll
't.Whentheid|espeedisoutofspeciiicationandthescantoo|doesnotindicateDiagnosticTroub|ecode(DTc)P0505
or P1508. check the following items:
. Adiust the idle speed {see page 11-220}
. Starter switch signal (see page 11-202)
. Air conditioning signal (see page l1-204)
. ALT FR signal (see Page 11-2081
' Brake switch signal (see page 11-210)
. PSP switch signal (excapt Canada model) (see page 11-212)
. A,/T gear position signal {see section 14, Dl6Y5 engine (CVT):
page 11-216). Clutch switch signal (D16Y5 engine with M/T) (see page 11-218)
. Hoses and connections
' IAC valve and its mounting O-rings
lf the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 11-220)
|ftheid|espeedsti||cannotbeadjustedtospecification(andthescantoo|doesnotindicateDTcP0505orP]50S)
after IAC valve replacement. substitute a known-good ECM/PCM and recheck. lf symptom goes away, replace the
original ECM/PCM.

ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)