1999 HONDA CIVIC ac system

l,a
Crankshaft Position/Top Dead Center/Cylinder Position (CKP/TDC/CYPI Sensor
Thescantoo|indicatesDiagnosticTroub|ecode(DTc)P1359:Aprob|eminthecrankshaftPosjtion/TopDead
Center/Cvlinder Position (CKP/TDC/CYP) sensor circuit'
- The MIL has been reported on- DTC P1359 is stored
Problem veritication:1. Do the ECM Reset Procedure
2. Stan the engine lftheengine
won't start, crank it for at least
10 seconds-
lntermittent failure, sYstem is OK
Check for poor connecllon3 or
loose wires at C120 {distributor}and ECM,/PCM.
ls DTC P1359 indicated?
Check for poor connections or
loose wires between the distribu
tor and the ECM/PCM
Substitute a known'good ECM/
PCM, and rccheck. lt 3ymPtom/
indication goes awtY, rePlace
the original ECM/PCM.
r ta
11-1A7

PGM-FI System
ECM/PCM lnternal Circuit
[Fi6oil th" """n tool indicates Diagnostic Trouble code (DTc) p1607: An EcM/pcM lnternal circuit probtem.
- The MIL has been reported on.- DTC P1607 is stored.
Problern verif ication:1. Do the ECN4/PCM Reset pro-
cedure.2. Turn the ignition switch ON t).3. Wait 10 seconds.
ls DTC P 1607 indicated?
Substitule a known-good ECM/PCM and recheck. lf symptom/indication goes away, .epl.ce theorigin.l ECM/PCM.
11-188

[F16551l Th" ""un toot indicates Diagnostic Trouble Code (DTC) P1681: TIVA,/TMB signal line failure
Problem verification:1. Do the ECM Reset Procedure.
2. Drive the vehicle Ior several
miles at varying speeds
lnt.rmittent failure, system is OK
at ihis time. Check tor Poor con-
nections or loos€ wires at C131
llocated under right side of dash),
C438 ITCM) and ECM.
ls DTC P1655 indicated?
Check lor an oPen in the wire(TMA line):1. Turn the ignition switch OFF
2. Disconnect ECM connector C(31P)from the ECM
3. Turn the ignition switch ON (ll).
4- Measure vo ltag e between
ECM connector terminal Cg
and body ground.
Check for a short in the wire
ITMA line,:Measure voltage between TCM
22P connector terminal No 7 and
body ground.ls there battery vohage?
Ropair shod in the wire bstwe€n
the EcM (C!l) and the TcM.ls there battery voltage?
Check for an open in the wire
{TMB line}:1. Turn the ignition switch OFF
2. Reconnect ECM connector c(31P).
3. Disconnect the 22P connector
from TCM.4. Turn the ignition switch ON (ll).
5. Measure vo ltage between
TCM 22P connector termlnal
No. 6 and body ground.
Repair open in the wire between
th€ EcM {Ca) and the TcM.
Check for a 3ho.t in the wire
{TMB lin6,:Measure voltage between ECM
connector terminal C30 and bodyground,
ls there battery voltage?
Substitute a known'good ECM
and recheck. It symPtom/indica'tion goes away, teplace the origi-
nal ECM.
Reoair short in the wile b6tween
the ECM {C30} and the TCM.ls there baftery voltage?
f,epair open in the wire between
the EcM (C30) and the TcM.
IJA/T Signal (TMA/TMBI ('96 - 98 Dl6Y5 engine with GW)
ECM CONNECTOR C 131P}TMA IGRYI
fcu22PCONNECTOR
ll
TMB*{PNK}
231678910
1t'12131415161718
232a252930
Wire side oI temale
terminals
tl,
1 1-189

ldle Control System
System Description
The idle speed ot the engine 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 bv theECM/PCM. When the IAC Valve is activated, the valve opens lo maintain the proper idle speed.
D16Y5, D16Y8, Br6A2 engine (M/T):
(ROTARYItac vat-vEEI{GINEcooLAI{T
VARIOUSsEI{SORS
VARIOUSSENSORS
INTAKE MANIFOTDDl6Ys {CVTl, D16Y8 engine lA/T):
D16Y7 engine:
{ROTABY)
;iy--, - --- INTAKEMANIFOLD
11-190

ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)

ldle Control System
ldle Air Control (lACl Vatve ('96 - 98 Dl6ys, Dl6yB engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem 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 inorder to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR ICl3A)
,flrcerh-:J iYEL/BLKI
!.__-,/ -lt(v)
-T-=
Wire side of female terminals
tAcv(BLK/
ELUI
ECM CONNECTOR A I32PI
Wire side oI lemal€ terminals
VALVE
6a10ll12t3r5t6l7t8t920232a
t*25&a2A3o
The MIL hss b€on repo.ted on.DTC P'l508 i. itorod.
Problem vorification:1. Do the ECM/PCM Reset Pro-cedure,Start the engine, and warm ituP to normal operating tem-perature.
Intormittont t!llur., sy.tcm b OKat thb tim6. Chsck fol poor con-ncctionr or loo3e wirot at C138(lAC valv.l.nd ECM.
ls DTC P1508 indicated?
Check for an opcn in the wiro(lGPl line):1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON (ll).
4. Measure vohage between bodyground and the IAC valve 2Pconnectorterminal No. 2.
R.prir opan in the wiro botwa.nIAC valv..nd PGM-FI main r.l.y.
Chock for an opon or sho in thewire (IACV linal:1. Turn the ignition switch OFFand reconnect the IAC valveconnector.2. Disconnect the ECM connectorA (32P).
3. Turn the ignit;on switch ON (ll).4. Measure voltage betweenbody ground and ECM con-nector terminal A12.
(To page 1l-195)
11-194

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

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