Jeep 1987 Wrangler Workshop Manual page 519

Ill
ENGINES
Ill
FUEL FEEDBACK SYSTEMS
CONTINUED
FROM PREVIOUS
I AGE
CONTINUED
FROM PREVIOUS
PAGE
YES
YES
LOCATE AND REPAIR
SHORT CIRCUIT RETEST.
REPLACE DOWNSTREAM
SOLENOID AND RETEST.
C O N T I N U E D
F R O M P R E V I O U S
P A G E
START ENGINE AND
MEASURE VOLTAGE FROM
MCU CONNECTOR PIN 46
TO GROUND
REPAIR OPEN CIRCUIT IN
WIRE HARNESS AND
RETEST.
YES
DISCONNECT VACUUM
HOSE FROM PORT D OF
DOWNSTREAM SOLENOID.
TEST VOLTAGE BETWEEN
MCU CONNECTOR PIN 1
AND CONNECTOR PIN 20
PIN 20 IS GROUND
DETERMINE IF VACUUM IS
PRESENT AT PORT D.
REPAIR AND RETEST
YES
REPLACE DOWNSTREAM
SOLENOID AND RETEST.
S E E
I.S.
N
O
T
E
S
REPLACE MCU AND
RETEST DOWNSTREAM
SOLENOID.
TURN ENGINE OFF.
CONNECT ALL
DISCONNECTED
CONNECTORS. PROCEED
TO TEST 8.
D O O C
83085L(J)