1994 HONDA INTEGRA Workshop Manual

PGM-FI System
A/T Fl Signal A/B (A/T only)
\[l0l- The Maltunction Indicaror Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 30: A problem In-L= the A/T Fl Signat A circuit between Transmission Control Module (TCMI and ECM.
tItil- The Malfuncrion Indicaror Lamp {MlL) indicates Diagnostic Trouble Code {DTCI 31: A problem In-Li!- the A/T Fl Signal B circuit between Transmission Controt Module (TCM) and ECM.
\.__r_/ \.__r_/-l 30 l- o'-l 3t l------ /----\
84'
+ulty? Continuity?
r: code 31 1A/T Fl signal Bl
11-76
Wlth tho SCS ahon connocrolconi|ocd {!o. p.g. 'l 1 -341, codo3O and/or 31 ars indicltod.
Oo ths ECM Resot Proceduro {seepag€ 'l 1-35).
Test drive necessary.Drive the car lor several miles sothat the transmission uDshifts anddownshilts several times.
Intormittant tsilu.o, sy3tem iB OKat thir tima,Chack lor poor connactions otl.ro!€ wiror at C419 (TCM] andECM.
Does the MIL indicare code30 and/or 31?
Turn the ignition switch OFF.
Connect the test harness to th€main harness only, not to the ECM(see p8go l'l-37).
Disconnect the 22P connectorfrom the TCM.
Check lor continuity between B3andlor 84' terminal and bodygrouno.
Ropair lhon in GRN/8LU or GRY'wiro b6twoon ECM (83 or 84'land tho TCM.
(To page 11-77)

(From page 1 'l-76)
Check for continuity on GRN/BLUor GRY'wire between 83 or 84'and 22P connector of the TCM.
Ropair open in GRN/BLU or GRY'wiro botwoon ECM lB3 or B4'land the TCM,
Substituts a known-good ECMand rochock. ll symptom/indica-tion goos 6way, roplaca tho origi-nal ECM.
11-77

ldle Gontrol System
System Troubleshooting Guide
NOTE:
a Acrosa each row in the chan, the sub-systems that could be sources of a symptom are ranked in the order they should
be inspected, starting with O. Find the symptom in the left column, read across to the most likely source, then reler
to the page listsd at ths top ot that column. It inspection showa the system is OK, try the next system @, etc.
a lf the idle speed is out of sp€cification and th€ Malfunction Indicator Lamp {MlL) does not blink Diagnostic Trouble
Code (DTC) 14, 9o to inspection describ€d on pags 1 1-81.
PAGE
SYMPTOM
IDTIOJUSTIiSCREW
IDLE AIRc0NTROt-
AIRcoN0fTtoNtitcSIGNAL
ALTER.NAION FNSIGNAL
AUTOMATICIRAI{SA(LEGtARP0sm0 stGIAt
ERAK€swrTcHSIGNAL
STARTERswtTcHSIGNAT
POWERSTEERII'IGPffESSUREswncHSIGNAL
FAST IOLETHERMO
HOSESANOCONNEC.TIONS
11-9511-4211-841 1-8611-8811-9011-92I 1-9311-94
DIFFICULT TO STARTENGINE WHEN COLD@o
WHEN COLD FAST IDLE OUT OFSPEC l1,0OO- 2,0OO rpm|o@o
ROUGH IDLEo
WHEN WARM RPM TOO HIGHooo
WHEN
TOO LOW
ldl6 3p6od b b€lowspecitisd rpm (no loadl@o
ldla 5p66d doos nolincraas€ alter initialo
On mod6l3 with auto-matic transmBsion, thsidlo sp€ed drops in 963ro
ldl6 sp€eds drops when8ir condilioner in ONoo
ldls spo6d drops when6ts6iing wh66l i6 turninC@o
ldla spoed lluctust63with alactrical loado
FREOUENTSTALLING
WHILE WARMING UP@o
AFTER WARMING UPo@
FAILS EMISSION TESTo
11-78
.,Hilffirl|,

System Description
The idle speed ot lhe engine is controlled by the ldle Air Control {lAC) Valve.
The valve changes the amount ot 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.
#l' ----rTo FGM-FIMAINRELAY
VARIOUSSENSORS
IAC VALVE
FASTIDLETHERMOVALVE
INTAKE MAI{IFOLD
(cont'd)
BLK
r
11-79

ldle Control System
System Description (cont'd)
1 . Atter the engine slarts. the IAC valve opens for a censin time, The amount ot air is increased to raise the idle soeedabout 15O-3OO rom.
2. When the coolant temperature is low, the IAC valve is opened to obtain the proper fast idle speed. The amount ofbypassed air is thus controlled in relation to the engine coolant temperature.
IDI-E SPEEDlrpm)
176
80
ENGINECOOLANT TEMPERATURE
t"Fl(oct
11-80

1. when the idls speed is out of specification and the Malfunction Indicator Lamp (MlLldoes not blink Diagnostic Trou-
ble Code (DTC) 14, check the tollowing items:. Adiust the idle speed {see page I1-95). Air conditioning signal (see page l1-84). ALT FR signal (see page '11-86)
A/T gea, position signal (see page 11-88)
Erake switch signal (see page 1 1-90)
Starter switch signal (see page 1l-921
PSP switch signal (see page 1 1-93)
Fast idl6 thormo valve (see page l1-94)
Hoses and connsctions
IAC valve and its mounting O-rings
2. lf the above items are normal, substitute a known-good IAC vslv€ and readjust the idle speed (see page 11-95)'
. It the idle speed srill cannot be adjusted to speciJication (and the MIL does not blink code 14) after IAC valve
roplacement, substitute a known-good ECM and recheck. It symptom goes away, replsce the original ECM.
1 1-81

ldle Control System
ldle Air Control (lACl Valve
lt6l- -l lf l- The Maltunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code {DTC} 14: A problem in
' '- the ldle Air Control llAC) Valve circuit.
The IAC Valve changes the amount of air bypasEing the throttle body in respons€ to a current signal from the ECM in
order to maintain the proper idle speed.
ffi: r;611/ | /--T-\
- The MIL h.3 been report don,- With tho SCS shon connoctolconnoctod (soo pago 'l 'l -341,
cod6 14 is indicatod.
Do the ECM Reset Procedure (seepage 11-35).
With the engine running snd theaccelerator pedal releas€d, dis-conn€ct th€ 2P connector frorttho IAC valvo.
ls the MIL on and does it indicatecode 14?
htarmitlaot frlu]., aya-t.m i. OK !t thir tlft.
ll.rl drlv. mly ba nac-aaaaryl.Chack tor Doo. conn€c-tlonr oi loora wirca atC3O5 (loc.t.d .t |.ftlhock tow.tl, C424,Cl tB (lAC v.lvol .ndECM.
Disconnect the 2P connector fromthe IAC valve.
Sub.iituto . known{ood IACvdva lnd iotolt.
{To page 11-83}
11-82

(From page 'l 1-82)
Measure voltago between theYEL/BLK wire and bodv ground.
R.pair op.n In YEL/8LK who b.-twoon IAC vCvc dd PGM-FI mdnrelay.ls th€rs battery voltage?
Turn th€ ignition swirch ott andreconnect thg 2P cohnector to theIAC valve.
Conn€ct the test hs.ness "A"
connector to the main wirs hrr-n6ss only, not the ECM lsee page
t 1-37).
Tu.n tho ignition switch ON.
Momentarily connect Ag torminalto 423 terminol seveaal tim€s.
Sub.titutr ! known{ood ECM.nd ral..t. lt .ymptom/hdlcatioogoa! awsy. rophca tia origlnalECM.
Does th6 IAC valve click?
Raplir op.n or rhort in 8LK/BLUwl]. b.tw.cn IAC v!lv..nd ECM(A91, It th. wlro L OK, r.Dhc.lheIAC v.lv..
IAC VALVEBLK/BLU { _ }
JUMPER WIRE
A9 l+) A23 {-l
1 1-83