Honda Civic Service Manual page 464

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) varve
circuit.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM in
order to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR ICl3A)
,flrcer
h-:J
iYEL/BLKI
!.__-,/ -lt (v)
-T
-=
Wire side of female terminals
tAcv
(BLK/
ELUI
ECM CONNECTOR A I32PI
Wire side oI lemal€ terminals
VALVE
6
a
10
l l
12 t 3
r5
t 6
l 7 t 8 t 9 20 23 2a
t*
25
& a
2A
3o
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 it
uP to normal operating tem-
perature.
Intormittont t!llur., sy.tcm b OK
at 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 2P
connector.
3. Turn the ignition switch ON (ll).
4. Measure vohage between body
ground and the IAC valve 2P
connectorterminal No. 2.
R.prir opan in the wiro botwa.n
IAC valv..nd PGM-FI main r.l.y.
Chock for an opon or sho in the
wire (IACV linal:
1. Turn the ignition switch OFF
and reconnect the IAC valve
connector.
2. Disconnect the ECM connector
A (32P).
3. Turn the ignit;on switch ON (ll).
4 . M e a s u r e v o l t a g e b e t w e e n
b o d y g r o u n d a n d E C M c o n -
nector terminal A12.
(To page 1l-195)
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