D. CHART 7 . NO DATA LINK AND BULB CHECK OKAY
NOTE This chart IS only to be used if
1) All basic mechanical checks and physical inspections have been performed with no problem found, and
2) Diagnosis of DDEC-II was started at step Start-1 (page 3-121 ) and you have now been referred here.
C7-1 Read Codes on the
Check Engine Light
l Unplug the DDR.
l Short pin A to pin M on the 12 pin
l Read codes flashing out on the
Check Engine light.
C7-2 Check Diagnostic
l Turn ignition off.
l Disconnect both the vehicle harness
and 6-way power harness
connectors at the ECM.
l Install a jumper wire between El
of the vehicle harness connector
and socket D of the 6-way power
l Read resistance between sockets
A and M on the 12 pin, DDL
C7-3 Check ECM
l Check terminals at both the vehicle
harness and 6-way power harness
connectors (both the ECM and
harness side) for damage; bent,
corroded and unseated pins
WHAT TO DO NEXT
Go to C7-4 (note: if you wish to
bypass diagnosis of a potential
data link or DDR problem for
now, go to CEL-3, page 3-131.)
Go to C7-2
The Diagnostic Request line
(ckt #1451) is open or an open
or poor ground exists at pin A of
the DDL Connector. Repair
open wire or bad ground, page
3-2. Then go to C7-30.
Go to C7-3.
Replace ECM. page 4-192.
Then go to C7-30.
page 3-2. Then go to C7-30.