1999 HONDA CR-V Idle system

PGM-FI System
Electrical Load Detestor (ELDI (USA Model) (cont'dl
The scan tool indicates Diagnostic Trouble Code {DTC) Pl298; A high voltage problem in the Electrical Load
Detector (ELD) circuit.
97 modsl:
ELD 3P CONNECTOR {C35,'I
Wire sido oI lemale terminals
r lzlrl--T_ow
/6 IBLKI
Y
Repail op€n in th. wire b€tws€ntho No. 15 ALTERNATOR SPSENSOR 17.5 A) tuse in theunder-dlrh fuso/r.lay box andth6 ELD.EL {GRN/NEDI
PCM CONNECTORS
Problam verification:1. Do the PCM Reset Procedure.2. Start the engine.3. Turn on the headlights.Intermittent tailuro, systcm is OK.t this time. Chack for ooor con-noction! or looro wire3 at C127{locaied on PCM brackot), C35{{ELDI and .t tho PCM.
Chack for an opan in tho wilellGl linol:1. Turn thg ignition and head-lights OFF.2. Disconnect the ELD 3P connector.3. Turn the ignition switch ON {ll).4. M6asure voltage b€tw€enbody ground and the ELD 3Pconnoctor terminal No. 1.
Chock lol !n open in the wireIGND linel:'1. Turn the ignition switch andheadlights OFF.2. Disconnect the ELD 3P conneqor,3. Check for continuity betweenbody ground and the ELD 3Pconnector terminal No. 2.
Ropair opon in th6 wi.e betweonth. ELD connector rnd GiO2,
Ch.ck lo. an open in th€ wiro (EL
line):Check for continuity between theELD 3P connector terminal No. 3and PCM connector terminal 016.
Chock for . malfunction in theELD:1. Reconnect the ELD 3P con-neclor,2. Start the engine and allow itto idle.3. While measuring voltagebetween PCM connector terminals 016 and A9. turn theheadlights on (low).
ls there continuityT
R6pafu op6n in tho wire betweenthe PCM {D161snd th6 ELD.
Subltituto . known-good PCMand rachock, f symptom/indic.-tion goes awry, ropl.ce the origi-n.l PCM.
Does the voltage drop?
Wire side of lemale terminals
11-140
Wire side of lemale terminals
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ldle Control System
System Description
The idle speed of the engjne is controlled by the ldle Air Control (lAC) Valve'
The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled by the
ECM/PCM. When the lAc valve is activated, the valve opens to maintain the proper idle speed.
YEL/ From PGM'FI
BLK TMAIN RELAY
VARIOUSSENSORS
4.
IAC VALVE
INTAKE MANIFOLD
After the engine starts, the IAC valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
when the cootant temperature ts row, the lAc valve is opened to obtain the proper fast idle speed The amount o{
bvoassed air is thus controlled in relation to the engine coolant temperature
When the idle speed is out o{ specification and the scan tool does not indicate Diagnostic Trouble Code (DTC) P0505
or P1508, check the following items:
. Adjust the idle speed (see page 11-169, 170)
. Air conditioning signal (seepagell-1551
. ALT FR signal (see page 1l-159)
. Starter switch signal (see page 11-16'1)
. A,/T gear position signal (see section 14)
. PSP switch signal (seepagell-162)
. Brake switch signal (see page 11-165)
. Fast idlethermovalve (see page'11 168)
. Hoses and connecttons. IAC valve and its mounting O-rings
lf the above items are normat, suDslitute a known-good IAC valve and readjust the idle speed {see page 11-169, 170)
lf the idle speed still cannot be adjusted to specification (and the scan tool does not indicate DTC P0505 or Pl508)
after IAC valve reolacement, substitute a known-good ECM/PCM and recheck lf symptom goes away' replace the
original ECM/PCM.
11-149
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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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ldle Control System
ldle Air Control llAC) Valve
The scan tool indicates Diagnostic Trouble Code (DTC) Pl508: A probtem in the ldle Air Controt flAC) varvecircuit.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM/PCM inorder to maintain the proper idle speed.
37 model;
IAC VALVE 2P CONNECTOR {C132}
,f rcp'# IYEL/BI.(II2f-1-d)
Y
Wir€ side of female terminals
PCM CONNECTOR A I32PI
tacvIBLK/BLU)
From AIR To INTAKECLEANER MANIFOLD
Wire side of female terminals
The MIL has beon .eport€d on.OIC Pl508 is sto.ed.
Problem veiification:1. Do the PCM Reset Procedure.2. Start the engine, and warm itup to normal operating tem-perature.
Inte.mittent failure, systcm b OKat thi3 time. Check tor poo. con-nections or loose wircs at C132(lAC v.lvel and at the PCM.
ls DTC Pl508 indicated?
Check lor an open in the wir6{lGPl lins}:1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON {ll).4. Measure voltage between bodyground and the IAC valve 2Pconnector term inal No.2.
Repair open in the wire trctwoontha IAC v!lv6 and the PGM-Flmain relly.
Chock for an opan o. short in thowi.e (lACv linel:1. Turn the ignition switch OFFand reconnect the IAC valve2P connector.2. Disconnect the PCM conneclorA (32P).
3. Turn the ignition switch ON {ll).4, Measure voltage betweenbody ground and PCM con-nector terminal A12.
{To page 1l-153)
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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 Control System
Fast ldle Thermo Valve lA/T)
Description
To prevent erratic running when the engine is warming
up, it is necessary to raise the idle speed. The fast idle
thermo valve is controlled by a thermowax plunger.
When the engine is cold, the engine coolant surround-
ing the thermowax contracts the plunger, allowing addi-
tional air to be bvDassed into the intake manifold so that
the engine idles faster. When the engine reaches operat-
ing temperature. the valve closes, reducing the amount
of air bypassing into the intake manifold.
IDLEADJUSTING
IDLETHERMOVALVE
AIR BYPASS VALVE
11-168
Inspgction
NOTE: The fast idle thermo valve is factory adjusted; it
should not be disassembled.
1. Remove the intake air duct from the throttle body.
2. Start the engine,
3. Put your finger over the lower port in throttle body,
and make sure that there is air flow with the engine
cold (engine coolant temperature below 86"F, 30'C).
lf there is no air flow, replace the fast idle thermo
valve and retest,
O-RINGSReplace.
11.0 kgfl.m, 7.2 lbl.ftl
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.
Check that the valve is completely closed. lf the valve
is leaking, the idle speed will drop when you cover the
lower pon. Check the engine coolant level and for air
in the engine cooling system {see section 10). lf the
cooling system is OK, replace the fast idle thermo
valve and recheck.
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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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