ldle Control System
ldle Control System
I P0505 | The scan tool indicates Diagnostic T.ouble Code (DTCI PO5O5: ldlecontrol svstem mattunction.
NOTE: lf DTC P1508 is stored at the same time as DTC P0505, troubleshoot DTC P1508 first. then troubleshoot DTC p0505.
Possibls Cause
. IAC valve mechanical malfunction. Throttle body clogged port, improper adlustment. Intake manifold gasket leakaging. Intake air hose loose leakaging. Vacuum hose leakaging
a ECT sensor incorrect output. Throttle Position sensor incorrect output
Troubleshooting Flowchart
The MIL has been reDorted on.DTC P0505 is sto.ed.
Problem verificationi1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator Ian comes on, thenlet it idle.2. With the scan tool, check thelollowing items.- Throttle position should beapprox. 10% with the throt-tle {ully closed.- Engine coolant temperature shorJld be 194 - 205'F(90 - 96"C).lf they are not within thespec., repair the faulty sen-sor circuit.3 Check the engine speed atidle with no-load conditions:headlights, blower fan. reardefogger, radiator lan, and airconditioner are not operaling,
Inte.mittent failure. syltem is OKat this time.ls it 750 {730)* i 50 rpm?
ls il 700 (680)' rpm or less?
{To page 11-151)(To page 1'l-151)
l:'99 - 00 models
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Alternator (ALT) FR Signal
This signals the ECM/PCM when the Alternator (ALTI is charging.
,97 modet: PCM GONNECTORS
wire side of female terminals
ALT CONNECTOR (C1O5I
lPr-F- ALT F
lll2llw|{frREDl|3.r-'l-
lruueen wne
c (31P|
wire side ol f€male terminals
PCM CONNECTOR C I31P)
3Pr
JUMPERWIRE
Inspection ot ALT FR Signal.
Check lor a short in the wire
{ALT F line}:1. Disconnect the 4P 13Pi* connector from the ALT.2. Turn the ignition switch ON (ll)
3, Measure voltage betweenPCM connector terminals C17
and A9.Check for a short in the wire(ALT F linel:1. Turn the ignition switch OFF.2. Disconnect the negative bat'tery cable from the battery.3. Disconnect PCM connector C(31P).
4. Check for continuity betweenbody ground and PCM connector terminal C17.
ls there approx. 5 V?
Check th€ ope.ation of the ALT:
1. Turn the ignition switch OFF2. Reconnect the ALT 4P {3Pi*connector to the ALT.3. Start the engine. Hold theengine at 3,000 rpm with no
load (in Park or neutral) untilthe radiator fan comes on,
then let it idle.4. Measure voltage betweenPCM connector terminals C17and A9.
Ropeir short in the wir6 betweonthe PCM lC17l and the ALT.
Substitut. a known-good PCM
and recheck. lf prescribed volt-
age is now availablo, replace the
originalPCM.
Does the voltage decrease when
headlights and rear defogger are
turned on?ALT FR signal b OK.
Ch€d( for an op€n in tho wire IALTF linel:1. Turn the ignition switch OFF.2. Disconnect the negative bat-tery cable lrom the battery.3. Disconnect PCM connector C(31P).
4. Disconnect the 4P (3P)* con-nector lrom the ALT.5. Connect the ALT 4P (3P)* con-nector terminal No. 4 (No. 1)*to body ground with a iumper
6. Check for continuity betweenbody ground and PCN4 con'nector terminal Cl7.
Repair open wi.e between thePCM lCl7l and the ALT.ls there continuity?
ALT F IWHT/REDI
Wire side of female terminals
1 1-159
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ldle Gontrol System
Alternator (ALT) FR Signal (cont'dl
'98 - 00 modols:
ALT CONNECTOR (C1I}5I
4P
rH] Arr Fl'l'ltwHr/REo)l3laF1
I JUMPER WIRE JUMPER+ WIRE
ECM/PCM CONNECTORS
Wire side of female terminals
ECM/PCM CONNECTOR C {31PI
Wire side of female terminals
Wire side of female terminals
ECM/PCM CONNECTOR C {31P}
": Canada
1 1-160
B (25P)
Insp€ction of ALT FR Signsl.
Check fo. a shon in th. wire {ALTF linel:1. Disconn6ct the 4P (3P)* con-nector from the ALT.2. Turn the ignition switch ON {ll).3. Measure voltage between ECM/PCM connector terminals C5and 820.Ch€ck for a sho.t in iho wirc lAlTF lino):1. Turn the ignition switch OFF.2. Disconnecl the negative bat,tery cable from the battery.3. Disconnect ECM,PCM connec-torC (31P).
4. Check for continuity betwoenbody ground and ECM/PCMconnector terminal c5.
ls there approx. 5 V7
Check the opcration of the ALT:1. Turn the ignitioo switch OFF.2. Reconnect rhe ALT 4P (3P)*connector to the ALT.3. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator lan comes on,then let it idle.4. Measure voltage between ECM/PCM connector terminals C5and 820.
Roprir lhort in tho wirc bstweentho ECM/PCM {Csl and the ALT.
Substitut. r known-good ECM/PCM and roch.ck. It Droscrib.dvoltage b now lvrilabls, .eplaccth. o.igin!l ECM/PCM.
Does the voltage decrease whenheadlights and rear defogger areturned on?ALT FR 3ignol is OK,
Chock lor an opon in tha wire (ALTF linel:1. Turn the ignition switch OFF.2. Disconnect the negative bat-tery cable from the battery.3. Disconnect ECM/PCM con-nector C (31P).4. Disconnect the 4P 13P)* con,nector from the ALT.5. Connect the ALT 4P {3P)* con-nector terminal No. 4 1No. 1)*to body ground with a jumper
6. Check for continuity betwe€nbody ground and ECM/PCMconnector terminal C5.
Rsprir opan wiro batw.en thoECM/PCM lcsl .nd th. ALT.ls there continuity?
AI.T F IWHT/REDI
ALT F {WHT/REDI
Wire side ot Iemale terminals
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ldle Speed Setting
Inspoction/Adiustmont
37 modsl:
NOTE:
. Before setting the idle speed, check the following
items:- The MIL has not been reportsd on.- lgnition timing- Spark plugs
- Air cleaner- PCV system
. lcanada) Pull the parking brake lever up. Stan the
engine, then check that the headlights are off.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
Connect a tachometer or a Honda PGM Tester.
Disconnect the 2P connector from the ldle Air Con-
trol (lAC) valve.
IAC VALVE
lf the engine stalls, restart the engine with the accel-
erator pedal slightly depr6ss6d, Stabilize the rpm at
1,000, then slowly release the pedal until the engine
idles.
Check idling in no-load conditions: hsadlights,
blower fan, rear d€fogger, radiator fan, and air con-
ditioner are not operating.
ldle spood should b.:
{80 t 50 rpm {in Park or noutr.ll
IDLE
7.
Adjust the idle sp6ed,
idle adjusting screw.
if necessary, by turning the
Turn the ignition switch OFF.
Reconnect the 2P connector to the IAC valve, then
remove the BACK UP (RAD|Ol (7.5 Al fuse in the
under-hood fuse/rslav box for 10 seconds to reset
the PCM.
Restart and let the engine idle with no-load condi-
tions for one minute, then check the idle speed.
NOTE: (Canadal Pullthe parking brake lever up. Stan
the engine, then check that the headlights are off.
ldlo Ep€ed rhould be:
75O t 50 rpm (in P.rk or noutr.ll
Let the engine idl6 for one minute with the head-
lights (Low) ON, and check th€ idl€ speed.
ldle lpcod 3hould bo:
750 t 50 ]pm (in Park or nautlal)
Turn the headlights off. Let th€ engine idle for one
minute with the headlights (Low) ON, heater fan
switch at Hl and air conditioner on. then check the idle
sDeeo.
ldl. specd should b6:
7d) 1 50 rpm {in Park or nautral}
lf the idle speed is not within specification, see the
symptom chart on page 11-64. (cont'd)
1 1-169
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ldle Control System
ldle Speed Setting (cont'd)
38 - 0O mod6l3:
NOTE: Before setting the idle speed, check the follow-
ing items:- The MIL has not been reported on.- lgnition timing- Spark plugs
- Air cleaner- PCV system
1. Start the engine. Hold the engine at 3.000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
Connect a tachometer.
Disconnect the IAC valve 2P connector and the EVAP
purge control solenoid valve 2P connector.
CONTROLSOLENOID VALVE
SOLENOID VALVE
lf the engine stalls, restart the engine with the accel-
erato. pedal slightly depressed. Stabilize the rpm at
1,000, then slowly release the pedal until the engine
idles.
Che€k the idle in no-load conditions: headlights, blow-
er fan, rear defogger, radiator fan, and air conditioner
are not operating,
ldle speed should bo:
480 t 50 rpm {in PErk or noutrall
11-170
lf necessary, adjust the idle speed, by turning the
idle adjusting screw.
After adjusting the idle speed, recheck the ignition
timing (see section 4). lf it is out of spec, go back to
steo 4.tDt.E
6. Turn the ignition switch OFF.
7. Reconnect the 2P connectors to the IAC valve and
the EVAP purge control solenoid valve, then do the
ECM/PCM reset procedure.
8. Restart and idle the engine with no-load conditions
for one minute, then check the idle speed.
ldle speod should be:,98 model:
750 t 50 rpm tin Park or neutral)'9!l - 00 modsls:
730 i 50 lpm lin Psrk or neutral)
NOTE: lf the idle speed increases to 780 t 50 rpm(770 1 50 rpml*, this means the EVAP system is
purging the canister. To stop the purging temporari-
ly, raise the engine speed above 1,000 rpm with the
accelerator pedal, then slowly release the pedal.*: '99 - 00 models
9. Let the engine idle for one minute with the head-
lights (Low) ON, and check the idle speed.
ldle speed should be:
38 mod6l:
750 f 50 rpm (in Palk or neutrall'99 - 00 modols:
730 t 50 rpm (in Palk or neutral)
10. Turn the headlights off. Let the engine idle for one
minute with the heater fan switch at Hl and air con-
ditioner on, then check the idle speed.
ldls spqed should be:'98 model:
780 t 50 rpm (in Park or neutrall'99 - 00 mod€ls:
7701 50 rpm lin Park or neutral)
lf the idle speed is not within specification. see the
Symptom Chart on page 11-64.
ADJUSTING
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Fuel Pump
Testing
lf you suspect a problem with the fuel pump, check that
the fuel pump actually runs; when it is oN (ll), you will
hear some noise if you hold your ear to the fuel fill port
with the fuel fill cap removed. The fuel pump should run
for two seconds when ignition switch is first turned ON (ll).
lf the fuel pump does not make noise, check it as follows:
1. Fold the left rear seat cushion forward, and remove
the base frame cover (see section 20).
2, Remove the access panel from the floor.
3. Make sure the ignition switch is OFF, then discon-
nect the fuel pumP 5P connector.
4. Connect the PGM-FI main relay 7P connector termr-
nal No. 4 and No, 5 with a jumper wire.
PGM.FI MAINRELAY 7P CONNECTOR (Cit:}2l
I'TtlJilt f -r'-r ll.l5l517l,frTt-,at\FUEL pUMp Lr- . tcl tyEL/cRNl
rYEL/cRNl IIJUMPER Wir€ side of
WIRE female terminals
5. Check that battery voltage is available between the
fuel pump 5P connector terminal No. 4 and body
ground when the ignition switch is turned ON (ll).
FUEL PUMP 5P CONNECTOR {C562}
12
3a5
lf battery voltage is available, check the fuel
pump ground. lf the ground is OK, replace the
fuel oumo.
lf there is no voltage, check the wire harness (see
page 11-188).
FUEL PUMP(YEL/GRNI
wire side offemale terminals
Raplac6mont
1. Fold the left rear seat cushion forward, and remove
the base frame cover (see section 20).
2. Remove the access panel from the floor.
3, Relieve the fuel pressure (see page 11-178).
4. Disconnect the fuel lines.
5. Disconnect the 5P connector from the fuel pump.
6. Remove the fuel pump mounting nuts.
7. Remove the fuel pump from the fuel tank.
Install the fuel pump in the reverse order of
removal.
8.
11-183
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Fuel Supply System
Fuel Gauge
Tssting
NOTE: Refer to section 23 for the fuel gauge system cir-cuit diagram.
'1. Check the No. 25 METER (7.5 A) fuse in the under-dash fuse/relay box before testing.
2. Fold the left rear seat cushion forward, and remove
the base frame cover {see section 20).
3. Remove the access panel from the floor.
4. Disconnect the 5P connector from the fuel pump.
5. Measure voltage between the 5P connector termi-nals No.2 and No. 5 with the ignition switch ON ( ).There should be between 5 and 8 V.
FUEL PUMP5P CONNECTOR
tc56al
a
a
Wire side of female t€rminals
lf the voltage is as specified, go to step 6.lf the voltage is not as specified, check for:- an open in the YEUBLK or BLK wrre.- poor ground (c552).
11-184
7.
Turn the ignition switch OFF.
Attach a jumper wire between the No. 2 and No. 5terminals, then turn the ignition switch ON fll).
Check that the pointer of the fuel gauge starts mov-ing toward the "F" mark. Turn the ignition switchOFF before the pointer reaches "F" on the gauge
dial. Failure to do so may damage the luel gauge.
NOTE: The fuel gauge is a bobbin (cross-coil) type,hence the fuel level is continuously indicated evenwhen the ignition switch is OFF, and the pointer
moves more slowly than that of a bimetal type.
. lf the pointer of the fuel gauge does not move atall. replace the gauge.
. lf the gauge is OK, inspect the fuel gauge send-ing unit.
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Fuel Gauge Sending Unit
Tgsting
@ Do not smoke while working on tho fuel
systom. Keop open flamo 8waY from your work araa.
1. Fold the left rear seat cushion forward, and remove
the base frame cover (see section 20).
2. Remove the access panel.
3. With the ignition switch OFF. disconnect the 5P con-
nector from the fuel pump.
4. Relieve fuel pressure (see page 11-178).
5. Disconnect the fuel lines.
6. Remove the fuel pump,
7. Measure the resistance between the No. 2 and No. 5
terminals at E (EMPTY), 1/2 (HALF FULL) and F (FULL)
by moving the float.
lf you do not get the above readings, replace the
fuel pump.
11-185
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