General Troubleshooting Information; Intermittent Failures; Opens And Shorts; How To Use The Pgm Tester Or A Scan Tool - Honda EP3 Service Manual

General Troubleshooting Information
Intermittent Failures
The term "intermittent failure" means a svstem mav
have had a failure. but it checks OK now. lf the
Malfunction Indicator Lamp (MlL) on the dash does not
come on, check for Door connections or loose terminals
at all connectors related to the circuit that Vou are
troubleshooting.
Opens and Shorts
"Ooen" and "Short" are common
electrical terms. An
open is a break in a wire or at a connection. A short is
an accidental connection of a wire to ground or to
another wire. In simple electronics, this usually means
something won't work at all. With complex electronics
( s u c h a s E C M s ) t h i s c a n s o m e t i m e s m e a n s o m e t h i n g
works, but not the way it's supposed to.
How to Use the PGM Tester or a Scan Tool
lf the MIL {Malfunction Indicator Lamp} has come on
' 1 .
S t a r t t h e e n g i n e a n d c h e c k t h e M I L { A ) .
N O T E : l f t h e i g n i t i o n s w i t c h i s t u r n e d O N ( l l ) , a n d
the engine is not started, the MIL will stay on for
1 5 2 0 s e c o n d s ( s e e p a g e 1 1 - 4 6 ) .
K-> ;"PN/.- -::: - -d V-: !
w:ix&K#
2. lf the MIL stays on, connect the Honda PGM Tester
(A) or an OBD ll scan tool to the Data Link
Connector {DLC) (B) located under the driver's side
o f t h e d a s h b o a r d .
3 .
5 .
T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
Check the Diagnostic Trouble Code (DTC) and note
it. Also check the freeze data. Refer to the DTC
T r o u b l e s h o o t i n g I n d e x , a n d b e g i n t h e a p p r o p r i a t e
troubleshooting procedure.
lf you do not find any DTCS, go to MIL circuit
t r o u b l e s h o o t i n g ( s e e p a g e 1 1 - 9 7 ) .
NOTE:
. Freeze data indicates the engine conditions when the
first malfunction, misfire, or fuel trim malfunction
was detected.
. The scan tool and the Honda PGM Tester can read the
DTC, freeze data, current data, and other Engine
Control l\4odule {EClvl) data.
. For specific operations, refer to the user's manual
that came with the scan tool or Honda PG l\4 Tester.
lf the MIL did not stay
lf the MIL did not come on but there is a driveability
problem, refer to the Symptom Troubleshooting Index
i n t h i s s e c t i o n .
lf you can't duplicate the DTC
Some of the troubleshooting in this section requires
you to reset the ECM and try to duplicate the DTC. lf rhe
problem is intermittent and you can't duplicate the code,
d o n o t c o n t i n u e t h r o u g h t h e p r o c e d u r e . T o d o s o w i l l
o n l y r e s u l t i n c o n f u s i o n a n d , p o s s i b l y , a n e e d l e s s l y
r e p l a c e d E C M .
( c o n t ' d )
1 1 - 3