1998 ACURA INTEGRA Service Repair Manual

J
a
I
lF1660l Th"""untool indicates Diag nostic Trou ble code (DTC) P1660:Aproblem in theA./rf Fl data line.
Wire side of temale terminals
(conr'd)
ECM CONNECTOR C I31P}
ATCHK{BLUI
1 2 3 1l 15 6 710
11 t2 131r t5 16 1? t8'tg /21
././I l/nzex)
TCM CONNECTOR 26P (C,r2ol
7 r-T7 s 6 ;i-g-io-rrJzlil
15 16 17 / /.20 22 23 21 25 26
ATCHK IBLU)
o
ECM CONNECTOR C {31PI
Th6 MIL has been reported on.DTC P16GO is stored.
Problem verificationl1. Oo the ECM Reset Procedure.2. Turn the ignition switch OFF.3. Start the engane. Allow theengine at idle for one minute,
lntermittent failure, swtem is OKat lhis time. Check lor poor con-n€ctions or loose wires at C420ITCMI and ECM.
ls DTC P1660 indicated?
Check for an open in the wire
{ATCHK line}:1. Turn the ignition switch OFF.2. Check for continuity betweenECM connecto. terminal C19and TCM 26P connector terminal No.20.
Repair open in the wire betweenECM (Cl9) and TCM.ls there continuity?
Check tor a short in the wire{ATCHK line):1. Disconnect the ECM conoec'tor C (31P).
2- Disconnect the 26P connectorfrom the TCM.3. Check for continuity betweenbody ground and EcM connector terminal Cl9-
Repair short in the wire betweenECM lC19) and TcM.
(To page 11-94)
11-93

PGM-FI System
A/T Fl Data Line (cont'dl
(From page '11-93)
Check fo. an ooen or rhort in thewires llGl, LG lines):Measure voltage between TCM 26Pconnector terfiinals No. 12 and 13and terminals No. 25 aod 26.
- Ropair opan or short in thewire bgtwoen TCM and No. 15ALTERNATOR SP SENSOR17.5 Al tu3e in th€ under-dashfu3e/r€lay box.- Repair opon in tho wireb.twoen TCM and G101.
ls there banery voltage?
Check to. an open o. 3hort in thaTCM:Substitute a known-good TCMand recheck.
ls DTC P1660 indicated?
Substitute a known.good ECMand rschsck. lf symptom/indica-lion 9o€! .w.y, roplace tho origi-nal ECM.
TCM CONNECTOR 26P {Cir2ol
LG(BRN/
BLK}
1 2 3 ,/ 5 6 7 E 910 11
14 15 16 17
Wir6 side of lemale terminals
i
-94

JP1681 | The scan tool indicates Diagnostic Trouble Code (DTC) P1681: A low voltage problem in the A/T Fl signal A
circuit.
P1682 | The scan tool indicates Diagnostic Trouble Code {DTC) Pl682: A high voltage problem in the A//T Fl signal A
circuit.
]TtOgOl fh" scan tool indicates Diagnostic Trouble Code (DTC) P1686: A low voltage problem in the A"/T Fl signal B
ctrcutt.
lFt Ogt-l fh" scan tool indicates Diagnostic Trouble Code (DTC) P1687: A high voltage problem in the A"/T Fl signal B
crrcurt.
ECM CONNECTOR C {31PI
IGRN/BLU)
Wire side of female terminals
TCM CONNECTOR {22P) {C419}Wire side of female terminals
2!a5't0
tl1213 tatat6It1a19 ,/
AFSB I I AFSA
{GRYI T- _IIGRN
@)o
2311to21 ;'15 15 17 13 13
E./ zl za
G-\
AFSIGR
\-
a
AFlGl
I
sBl
L]
r@!I AFSA
| {GRN/lRt ltl
iFSGRIA[/BLUt
12 3 a 5 6 7 89
tz /'tt //t't /ts zo
to ,/
DTC P1681, P1682, P1686 end/or P'1687 are stored.
Problem verificetion:1. Do the ECM Reset Procedure.2. orive the car for several milesso that the transmissionupshifts and downshifts severarlrmes.
Intormittent lailure. system is OKat thi3 tim€. Check tor ooo. con-nections or loo3o wir6s al C419{TCM} .nd ECM.
ls DTC P1681, P1682, Pl686and/or P1687 indicated?
Check tor a short in th6 wires{AFSA, AFSB linel:1. Turn the ignition switch OFF.2, Disconnect the 22P connectorfrom the TCM.3. Disconnect the ECM conn6c-tor C (31P).
4. Check for continuity betweenbody ground and ECM con-nector terminal C28 (C27)*.
Rcoair 3hort in tho wiros betweenECM lC28 or C27*l rnd TCM.ls there continuity?
Check fo. an open in the wiresIAFSA, AFSB lines):Check for continuity between ECMconnector terminal C28 (C27)* andTCM 22P connector terminal No. 7(No.6i*.
Repai. opsn in the wiros bdtweenECM lC28 or C27'l and TCM.
Subsiiiutg a known-good ECMend r6ch€ck. lf 3ymptom/indica-tion goes away, repl.c6 the origi-nal ECM.
":DTC P1686 or Pl687 (NT Fl sisnal 8l
1 1-95

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

ldle Control System
ldle Control System
i P0505 | fne scan tool indicates Diagnostic Trouble Code (DTC) P0505: ldle control system malfunction,
NOTE: ll DTC Pl508 is stored at the same time as DTC P0505, troubleshoor DTC P1508 first. then troubleshoot DTC P0505.
Possible Cause
. IAC valve mechanical malfunctiorr
. Fast idle thermo valve malfunction (A"/T)
. Throttle body clogged port, improper adjustment
. Intake manifold, gasket leakage
. Intake air hose loose, leakage
a Vacuum hoses leakage
. ECT sensor incorrect output
. Throttle Position sensor incorrect output
Troubleshooting Flowchart
Problem verification:1. Start the engine. Hold theengine at 3,000 rpm wath noload 1in Park or neutral) untilthe radiator fan comes on,then let it idle.2. With the scan tool, check thefollowing items.- Throttle position should beapprox. 10% with the throttle fully closed.Engine coolant tempera-ture should be 116 212F(80 - 100'c).lf they are not within thespec., repair the faulty sensor crrcuft,3 Check the engine speed atidle with no-load conditions:headlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating,
- The MIL has been reported on.- DTC P0505 is stored.
ls it 750 t 50 rpm (81881,
818C1 engines), 800 I 50 rpm(818C5 engine)?
Intermittent failur6, svstsm is OKat this tim€.
ls it 550 rpm (81881,818C1
engines), 600 rpm {818C5enginelor less?
-98
(To page 11'99)(To page 11-99)

Chock th6 IAC vrlv.:Disconnect the 2P connector tromthe IAC valve.
ooes lhe engine speed droporlhe engine stall?
Adiu3t th. lb.r.l idle Bp..d lrocplgc 11-1111.lf it's impo3.iblo, clo.n tho portsin thc throftlc body.
Ch.ck th€ frtt idl. th.rmo vrlv.:1, Turn the ignition switch OFF.2. Remov€ th6 intake air ductfrom the throttle body.3. Slart the engine and let it idle.4. Put your finger on the lowerport in the thronle bodv.
Chack angina coobnt Lv.l and fo.ai. in th. cooling ry.l.m. It OK,r.place tha fatt ldla lftarmo valva.Does the engine speed drop?
Put your linger on the uppor portin the throttle body.
Chacl tor vrcuum leek3, m.lcilJa th6 throttlo valvo ir com-plotaly cloaad, rnd ropair aa nac-a3aatY,
ooes ihe engin6 speed drop?
Adiutt th€ idl. .p..d l..r p.g.11-1111. lf it'. impo3riblo, rcpl.c.thc IAC v.lvc.
{A/T model)----tLOWERPORT
L. _. _._. _. _. _.-l
IDLETHERMOVALVE
1 1-99

ldle Control System
Problem verification:'1. Do the ECM Feset Procedure.2. Sta rt the engine.
ldle Air Control (lAG) Valve
The scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem in the ldle Air Control (lAC) valve
crrcurt.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the Eclvl in
order to maintain the proper idle speed.FTom AIB To INTAKECLEANER MANIFOLD
IAC VALVE CONNECTOR IC116}
YES
WIRE SIDE OF FEMALE TERMINALS
ECM CONNECTOR A {32PI
Check for an open or short in thewire IIACV line):1. Turn the agnition switch OFFand reconnect the IAC valve
2. Disconnect the ECM connector A (32P).
3. Turn the ignition swatch ON (ll).
4. M easu re voltage betweenbody ground and ECM connector terminal A12.
IACV {8LK/BLU}
tacv{BLK/BI-UI
The MIL has been reoorted on.OTC Pl508 is stored.
lntermittent failure, svstem is OKat this time. Check for ooor con-nections or loose wires at C116{lAC valvel and ECM.
ls DTC P1508 indicated?
Check tor an open in lhe wirellGPl line):1. Turn the ignition switch OFF.2. Disconnect the IAC valve con
3. Turn the ignition switch ON (ll).
4. Measure voltage betlveen bodyground and the IACV connectorterminalNo.2.
Repair open in the wire betweenIAC valve and PGM-FI main relav-ls there battery voltage?
Repair open or shon in the wi.ebetween ECM {A12l and lAc valve.ls there battery voltage?
Check the IAC velve function:Momentarily connect ECM con-nector terminals A12 and A10with a jumper wire several times.
Does the IAC valve click?
Substitute a known-good ECMand rocheck. lf symptom/indica-tion goes away. replace the origi-nal ECM.
','*',,'Llu.9', I l112 15 16 17 1a1o20/
l--12u1 z"-if1za-2"' . '1 .
910
t-r '21
Wire side of female terminals
JUMPER WIRE
1-100