Honda Civic Service Manual page 462

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. then
recheck 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 . S t a r t t h e e n g i n e . H o l d t h e
e n g ; n e a t 3 , 0 0 0 r p m w i t h n o
l o a d ( j n P a r k o r n e u t r a l ) u n t i l
t h e r a d i a t o r f a n c o m e s o n , t h e n
* r
l e t i t i d l e .
t2. with rhe scan toot, ct'eit Ge l
T h r o t t l e p o s i t i o n s h o u l d b e
a p p r o x . 1 0 % w i t h t h e t h r o t
t l e f u l l y c l o s e d .
E n g i n e c o o l a n t t e m p e r a -
t u r e s h o u l d b e 1 9 4
2 0 5 ' F
( 9 0 9 6 . C i .
l f t h e y a r e n o t w i t h i n t h e
s p e c . , r e p a i r t h e f a u l t y s e n
L . _ _ 9 o I 9 [ c r ] 4 1
l
3 . C h e c & t h e e n g i n e s p e e d a t
i d l e w i t h n o - l o a d c o n d ; t i o n s i
h e a d l i g h t s , b l o w e r f a n , r e a r
d e f o g g e r , r a d i a t o r f a n , a n d a i r
c o n d i t i o n e r a r e n o t o p e r a t i n g
\see page l1-22O - 223).
Intermittent tailure, system is OK
at this time.
ls the idle speed OK?
l s i t 5 5 0 r p m o r l e s s ?
( T o p a g e 1 1 , 1 9 3 )
* 1 r ' 9 6 m o d e l s o n l y
1 1 - 1 9 2
( T o p a g e l l - 1 9 3 )