Pontiac Fiero 1988 Service Manual page 695

8E3-C7-4 DR8VEAB1L1TY AMD EMISSIONS - F U E L INJECTION (PORT)
PORTED
fVIANIFOLO
VACUUM
IGN.
PNK/BLK
ECM
I.P. CONN.
EGR VACUUM DIAGNOSTIC SWITCH
5-26-87
639 ~ J
901 GRY/RED
997 D K 6 R N •
450 BLK/WHT
ENGINE
GROUND
0 8
D1
EGR CONTROL
rW—
12
V
L — S W I T C H SIGNAL
~1
5-8-87
* 5 S 1 9 1 4 - 6 E
CHART G 7
EXHAUST GAS RECIRCULATION (EGR) CHECK _
2.8L "P" SERIES (PORT)
Circuit Description:
The exhaust gas recirculation (EGR) valve is controlled by a normally closed solenoid (allow a vacuum to
pass when energized). The electronic control module (ECM) energizes the solenoid to turn the EGR "ON," and
monitors vacuum to the EGR with the EGR diagnostic switch. Code 32 will detect a faulty solenoid, vacuum
switch, or vacuum supply. CHART C-7 checks for plugged EGR passages, a sticking EGR valve, or a stuck
open solenoid.
Test Description:
Numbers below refer to circled
numbers on the diagnostic chart.
1. With the ignition "ON," engine stopped, the
solenoid should not be energized and vacuum
should not pass to the EGR valve.
2. Grounding the diagnostic terminal will energize
the solenoid and allow vacuum to pass to valve.
3. Checks for plugged EGR passages. If passages are
plugged, the engine may have severe detonation
on acceleration.
4. The EGR solenoid will not be energized in park or
neutral. This test will determine if the
park/neutral switch input is being received by the
ECM.