1997 HONDA CIVIC Repair

I
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(From page 11-194)
Repair open or short in the wirebetween ECM lAl2l and IAC
Check the IAC valve Iunction:Momentarily connect ECM con-
nector terminals A12 and A10
with a jumPer wire several times.
Does the IAC valve click?
Substitute a known-good ECM
and recheck. It symPtom/indica-tion goes away, replace the origi-
nal ECM.
Wire side of female terminals

ldle Gontrol System
ldle Air Control (lAG) Valve ('99 - 00 Dl6Y8 engine with M/T, Bt6A2 enginel
[Fl50g l ]h" scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem in the ldle Air Controt AC) vatve- CtrCUtt.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM inorder to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR IC138'
la rcprI - {YEL/8LKI 2t--d,
Y-=
Wire side ot female terminals
Wire side of lemale terminals
VALVE
The MIL has boon r€oorted on.DTC P1508 is srored.
Probl6m verification:1. Do the ECM/PCM Reset Pro-cedure.2. Start the engine, and warm itup to normal operating lem-perature.
Intermittent tailure, system is OKat this timg. Check to. poor con-noctions or loose wires at C138{lAC valvel and ECM.
ls DTC P1508 indicated?
Ch6ck for an open in the wir€{lGPl lino}: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 2Pconneclor termina I No.2,
Repair opon in the wire bgtwoenIAC valve and PGM-Fl main relay.
Check tof an open or short in thewire {IACV line}l1. Turn the ignition switch OFFand reconnect the IAC valve
2. Disconnect the ECM connectorB {25P).3. Turn the ignition switch ON (ll).
4. Measure voltage betweenbody ground and ECM conn€ctor terminal 823.
(To page 11-197)
1 1-1 96

t
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{From page 11-196)
Repair opon or short in lhe wire
between EcM lBzl) and lAc valve.ls there battery voltage?
Check the IAC valve fundion:Momentarily connect ECM con-
nector terminals 823 and 82 with
a iumpe. wire several tames.
Does the IAC valve click?
Substitute a known-good ECM
and rocheck. ll symptom/indicd-tion go€s away, rePlace tho origi_
nal ECM.
Wire side of female terminals
11-197

ldle Control System
ldle Air Control (lAC) Valve ('96 - 98 A/T and Dl6Y7 enginel
The (Rotary) IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from theECM/PCM in order to maintain the proper idle speed,
BIMETAL
VALVESTOPPER
1P1509 Thescantool indicates Diagnostic Trouble Code (DTC) P1509: A problem in the idle Air Control (tAC)valve circuit.
ECM/PCM CONNECTOR A I32PIPGl IBLKI
IAC VALVE 3P CONNECIOR
IACV NIACV P
IGP
Terminal side of maleterminals
*: IACV N line
1 1-198
The MIL has b€€n roported on.DTC P1509 is stored.
Problem verification:1. Do the ECM/PCM Reset Proce-oure.2. Turn the ignition switch ON (ll).
Intermittent failura, systom ia OKat this time. Check tor poo. con-noctions or loose wires at C109llAC valve) and ECM/PCM.
ls DTC P1509 indicated?
Check for an opon in the wirer{PG lines):Measure voltage between bodvground and ECM/PCII connectorterminals A10 and A23 individu
Repair op€n in the wires betwoenECM/PCM and G101 llocated attho thermostat housing).
ls there more than 1.0 V?
Chock th€ ECM/PCM inpui volt-agel1. Turn the ignition switch OFF.2. Disconnect ECM/PCM connec-tor A (32P)from the ECM/PCM.3. Turn the ignition switch ON (ll).4. Measu re voltage betweenbody ground and ECM/PCMconnector terminals A14 andA13* individually.
Ch6ck th6 IAC valve:1. Turn the ignition switch OFF.2. Disconnect the IAC valve 3Pconnector,3, Measure resistance betweenIAC valve 3P connector termi-nal No.2 and terminals No. 1and 3 individually.
ls there 16 - 28 g?
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goos away, replaceth€ origin.l ECM/PCM.
SHAFT
rAcv N loRNl*
(To page 11-199)
Wire side of lemale terminals
123a56El011
121314r5161718t9202:22321
272AA30
IACV P {BLK/BLUI

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IACV N(oRN)*IACV P{BLK/BLU'
ECM/PCMCONNECTON B (25PI
IACV N(oRNt.
Wire side of female terminals
IAC VALVE 3P CONNECTOR
IACV NIACV P
IACV P
IBLK/BLUI
IGP
Terminal side of male
(From page 11 200)
IAC VALVE 3P CONNECTOR {C1O9I
IGP (YEL/BLK)
Wire side of female terminals
Check toi an open in thg wire
{lGP line):1. Turn the ignition switch OFF.
2. Disconnect the IAC valve 3P
connector.3. Turn the ignition switch ON (ll)
4, At the wire harness, measure
voltage between IAC valve 3P
connector terminal No. 2 and
body gro!nd.
Repair open in the wire between
the IAC valve and PGM-FI main
reraY.
Check for an open in the wires
IIACV P. IACV N' lines):
1. Turn the ignition switch OFF.
2. Disconnect the ECM/PCM con-
nector A (32P).
3. Check lor continuity between
IAC valve 3P connector termi'nal No. 3 and ECM/PCM con-necto r terminal B6 (and
beNveen IAC valve 3P connector terminal No. 1 and ECM/PCM connector terminal 815)*.
Repair open in the wiro ltstwcen
the IAC valvo and €CM/PCM (86,
815'1.
Check for a shon in the wires(IACV P, lACv N* linesl:Check for continuity between
body ground and ECM/PCM con-
nector terminals 86 and 815*
individually.
Reoair short in the wiro Mweonthe lac valve end ECM/FCM (86,
815*).ls there continuity?
Check the IAC valv€:l. Disconnect the IAC Valve 3P
connector,2. Measure resislance betweenIAC Valve 3P connector termi
nal No. 2 and terminals No 1and No.3 individually
ls there 16 - 28 O?
Substituta . known-good ECM/
PCM and rochcdc f 3ymptom/indication go€a away, r€dace the original ECM/Pqvl.
"r IACV N line
N
11-201

ldle Control System
Starter Switch Signal ('96 - 98 Models,'99 - 00 D16Y5 engine with M/Tl
Thjs signals the ECM/PCM when the engine is cranking.
NOTE:. A/T: Transmission in E or E position. M/T: in neutral
a l32PlLGl
Wire side ot female lerminals
Check tor an open or short in thewire ISTS linel:Measure voltage between ECM/PCM connector terminals A9 andC6 with the ignition switch in thestart lllli position.
Inspect the No. 31 STARTER SIG-NAL (7.5 A) fuse in the underdashfuse/relay box.
- Repair .hort in the wirebotwoen tha ECM {C6l andtho No, 31 STARTER SIGNAL{7.5 Al tuss or the PGM-FImain relay,- Roolac. the No. 3'l STARTERSIGNAL l?.5 Al tu3€.
Staner 3witch signal is OK.
Repair opon in th6 wiro botweanih. ECII4/PCM (C6) and the No.31STARTER SIGNAL {7.5 Al tulo.
ECM/PCM CONNECTORS
{BRN/BLKISTS IBLU/ORNI
216910It3567a9l0
l2l3la15!6171a1920222att12t3l4t5t6171E
252l2A7t30232a2930
11-202

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Starter Switch Signal ('99 - 00 Models except Dl6Y5 engine with M/T)
NOTE:. M/f: Clutch pedal must be depressed.. A,/T: Transmission in E or E position
ECM,/PCM CONNECTORS
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This signals the ECM/PCM when the engine is cranking
Ch€ck for an open or short in the
wire {STS linel:Measure voltage between ECM/PC[/| connector terminals A24
and 820 with the ignition switch
in the start position (lll).
Inspect the No.31 STARTER SIG-NAL (7.5 Alluse in the under-dash
- Repair 3hort in tho wire be'
tween tho ECM/PCM lA24)and tho No. 31 STARTER SIG-NAL 17.5 Al fuse or the PGM-FImein relay.- ReDlaco the No. 31 STARTERSIGNAL 17.5 Al fuse.
Staner 3witch signal is OK.
Repair open in the wirc betwean
the ECM/PCM lA24) and the No.
31 STARTER SIGNAL {7.5 Alfuse.
W;re side of female terminals

(From page 11-204)
Check for an open in the wir€(ACC linel:Momentarily connect underhood
fuse/relay box 9P connector teF
minal No. 5 to body ground with
a iumper wire several times.
ls there a clicking noise from
the IVC compressor clutch?
See air conditionor inspection(see 3oction 221.ls there a clicking noise from
the Py'C compressor clutch?
Repair open in the wire between
rhe ECM/PCM lAl7l and th6
under-hood fu3e/rolaY box 9P
connector lC352l.
Check for the oPeration of the
Alcl1. Start the engine.2. Turn the blower switch ON
3. Turn the AJC switch ON.
Chock tor an open in the wire
IACS linel:Measure voltage between ECM/
PCM connector terminals A9 and
c5.
Does the Ay'C operate?
Air conditioning signal is OK.Repair open in the wire b€tweenthe EcM/PcM lC5) and the A/c
3witch.ls there less than 1.0 V?
- Substiiute a known-goodECM/PCM and recheck ll
symptom/indication 9oesaway, .oplace the originalECM/PCM.- See the air condhioner insP€c_tion {see s€c{ion 22).
UNDER.HOOD FUSE/BELAYBOX 9P CONNECTOR 1C352)
12Ia
589
ACC (BLK/RI
Wire side ofACC (BLK/REDI
Wire side of female
terminals
JUMPERWIRE
ECM/PCM CONNECTORSrfA t32P)
LGlc {31Pl
t
(BRN/BLK)ACS IBLU/RED)
I23a9101t3I89t0
121315l611la1920232att12't3la't5t617ta
25272A2930232a2930
Wire side of lemale terminals