Mazda 121 - Surges While Cruising

TROUBLESHOOTING GUIDE F
ta SUFGES WHILE CRUISING
DESCRIP.
TION
.
Unexpecled chanSe in engine speed wnich is usually repetitive
TIROUaLESHOOTTNG
HTNTSI
O
Air/Fuel mixture loo
ean
@
Misfirc
@
Poor connection
in
wiring harness
STEP tNSPECT|Ot{ ACTION
ls
'0O
displayed
on SellDiagnos s Checker
wth ignition
swltch ON?
c?
page
F-€?
Go 10
next
slep
No Malluncllon Code No. displ.yed
Check for cause
{Beler
lo soecilied
ch€ck s€quenc€) !?
page
F-70
"88"
llashes
Check
ECU ielminal 1F voltage e
p.ge
F-114
Vo[age: Approx. l2V
(lgnilion
sMtch ON)
+
lf
OK, replace ECU r?
page
F-112
+
lf not OK, check wirins benxeen
ECU and Self-Diagnosis Checker
2 ls throttle seosor OK?
s D4ge F-122
Go ro ne( step
NO
3 Disconnect oxyg€n sensor connector; does con'
OXYGEN
SENSOR
CONNEC] OFt
Check oxygen sensor
(?
eage
F-123
Are ECU terminal voltages OK?
t- page
F-112
Check
tor
cause
.7
pege
F-115
F-117
F-It9
5
ls
lh.ottle
linkage
cofrecly installed and does
thronde
valve
open op€raies lrcely?
Corfecl, clean,
or
replace as requircd
any binding or damaged
linkage,
and
adiusl
calte
dellection at
injeclion
body
F
page
F-{6
6
ls
there air
leakage
oi inlak€ arr system com-
7 ls arr cleaner element clean?
o
page
F-62
Beplace
air cl€aner elemenl
F-45