Honda EP3 Service Manual page 296

DTC P0300: Random Misfire and Any Combination of the Following:
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cvlinder Misfire
DTC P0303: No, 3 Cvlinder Misfire
DTC P0304: No. 4 Cvlinder Misfire
NOTE:
. lfthe misfiring is frequent enough to trigger detection of increased emissions during two consecutive driving cycles.
the MIL will come on, and DTC P0300 (and some comlrination of P0301 through P0304) will be stored.
. lf the misfiring is frequent enough to damage the catalyst, the MIL will blink whenever the misfiring occurs, and OTC
P0300 (and some combination of P0301 through P0304) will be stored. When the misfirlng stops, the MIL will remain
o n .
1. Troubleshoot the following DTCs first if any of them were stored along with the random misfire DTC(s):
P 0 ' 1 0 7 , P 0 1 0 8 , P 1 1 2 8 , P 1 1 2 9 r N 4 a n i f o l d a b s o l u t e p r e s s u r e ( M A P ) s e n s o r
P0111. P0'172t Fuel svstem
P0335. P0336: Crankshaft position (CKP) sensor
P0505: ldle control system
P1 149, Pl 162, P1 163, P1 164, P 1 165: Air fuel ratio (Ay'F) sensor
P1259: VTEC system
P1361, P1362: Camshaft position (CMP) sensor B {Top dead center (TDC) sensor)
P 1 5 1 9 : l d l e a i r c o n t r o l ( l A C ) v a l v e
2. Test-drive the vehicle to verify the symptom.
3. Findthesymptom inthechart below, and dothe related procedures in the order listed until you find the cause.
Symptom
Procedure(sl Also check foi:
R a n d o m m i s f i r e o n l y
at low RPM and
under load
Check fuel pressure (see page 1 1-145).
. Low compressron.
. Low quality fuel.
R a n d o m m i s f i r e o n l y
du ring acceleration
Check fuel pressure (see page 11-145).
Malfunction in the
VTEC system (see page
1 ' t - 1 2 3 ) .
Random misfire at
h i g h R P M , u n d e r
l o a d , o r u n d e r
random conditions
C h e c k f u e l p r e s s u r e ( s e e p a g e 1 1 - 1 4 5 ) .
Correct engine valve
clearances (see page 6-
9 1 .
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