Pontiac Fiero 1988 Service Manual page 594

DRIVEABILITY
A N D E M I S S I O N S » F U E L I N J E C T I O N ( P O R T ) 6 E 3 - A - 1 1
©
©
©
IGNITION " O N " . ENGINE " O F F "
IS T H E " S . E . S . " LIGHT " O N " ?
CHART A-2
NO ALDL DATA OR WON'T FLASH CODE 12
'SERVICE ENGINE SOON" LIGHT ON STEADY
2.8L "P" SERIES (PORT)
YES
• GROUND DIAGNOSTIC TERM.
DOES LIGHT FLASH CODE 12?
NO
r
T —
— — —
i
^ SEE CHART A-1 ^
NO
• IGNITION " O F F " .
• DISCONNECT ECM CONNECTORS.
• IGNITION " O N " AND NOTE
"SERVICE ENGINE S O O N " LIGHT.
©
LIGHT " O F F "
I
IGNITION " O F F " .
RECONNECT ECM.
IGNITION " O N " , ENGINE STOPPED.
DIAGNOSTIC TERMINAL NOT GROUNDED.
BACK PROBE ECM, CKT 451, WITH TEST
LIGHT TO GROUND.
NO CODE 12
• CHECK PROM FOR PROPER INSTALLATION.
© IF OK, REPLACE ECM USING ORIGINAL PROM.
® RECHECK FOR CODE 12.
NO CODE 12
REPLACE PROM
YES
® SF PROBLEM WAS NO ALDL DATA:
• CHECK SERIAL DATA CKT 461 FOR OPEN OR
SHORT TO GND. BETWEEN ECM AND ALDL
CONNECTOR. IF OK, IT IS A FAULTY ECM OR
PROM.
LIGHT "ON"
REPAIR SHORT TO
GROUND IN C K T 4 1 9 .
CODE 12
0
CHECK FOR OPEN IN ALDL DIAGNOSTIC
TERMS. " B " AND CKT 451 TO ECM.
® IF OK, CHECK FOR OPEN IN ALDL TERM
" A "
TO ECM.
1
CODE 12
SYSTEM OK
6-16-87
CLEAR CODES AND CONFIRM "CLOSED LOOP " OPERATION AND MO "SERVICE ENGINE SOON" LIGHT.
7 S 3 3 4 1
„
6 E