Pontiac Fiero 1988 Service Manual page 592

DRIVEABILITY AND EMISSIONS - FUEL INJECTION (PORT) 6E3-A-9
CHART A-1
NO "SERVICE ENGINE SOON" LIGHT
2.8L "P" SERIES (PORT)
DOES THE ENGINE START?
YES
X
IGNITION " O F F " .
DISCONNECT ECM CONNECTORS.
9
IGNITION " O N "
© PROBE CKT 419, WITH TEST LIGHT
TO GROUND.
I S T H E S . E . S . L I G H T " O N " ?
YES
X
FAULTY ECM
CONNECTION
OR ECM.
©
NO
CHECK:
- G A G E FUSE
- FAULTY BULB
- OPEN CKT 419
- C K T 4 1 9 SHORTED TO
V O L T A G E .
- OPEN IGN. FEED TO
BULB.
©
NO
IS ECM BATTERY FEED
CKT 240 AND ECM FUSE O K ?
YES
• IGNITION " O F F "
• DISCONNECT ECM
CONNECTORS.
• IGNITION " O N "
® PROBE CKT 240 8t 439
WITH TEST LIGHT TO
GROUND.
IS THE LIGHT " O N " ON
BOTH CIRCUITS?
YES
FAULTY ECM
GROUNDS O R E C M .
REFER TO ECM
Q U A D DRIVER
CHECK (CHART-C1)
1
NO
LOCATE AND CORRECT
SHORT TO GROUND IN
CIRCUIT THAT HAD A
BLOWN FUSE.
1
NO
X
REPAIR OPEN IN
CIRCUIT THAT DID NOT
LIGHT THE TEST LIGHT.
CLEAR C O D E S AND CONFIRM " C L O S E D LOOP " OPERATION AND NO "SERVICE ENGINE S O O N " LIGHT.
7-13-87
8S4665-6E