Test A - No Communication With Generic Electronic
Module
- To check circuit No. 785 (Black/Light Green wire) for power,
disconnect GEM connector C233. See Fig 1
. Measure voltage
from ground to GEM connector C233, pin No. 13 (Black/Light Green
wire). If battery voltage is present, go to step 5). If battery
voltage is not present, go to next step.
- To check circuit No. 785 (Black/Light Green wire) for short to
ground, remove fuse No. 19 (10-amp) from fuse junction panel. Measure
resistance from ground to GEM connector C233, pin No. 13 (Black/Light
Green wire). See Fig 1
. If resistance is
less than 10 k/ohms, repair circuit No. 785 (Black/Light Green wire)
for short to ground. Replace fuse No. 19 and retest system. If
resistance is more than 10 k/ohms, go to next step.
- To check power supply to fuse No. 19, remove fuse No. 19
(10-amp) from fuse panel. Measure voltage at fuse No. 19 input cavity.
If battery voltage is present, go to next step. If battery voltage is
not present, repair electrical supply to fuse No. 19 and retest
system.
- To check circuit No. 785 (Black/Light Green wire) for open,
measure resistance between output cavity of fuse No. 19 and GEM
connector C233, pin No. 13 (Black/Light Green wire). See Fig 1
. If resistance is 5
ohms or less, replace fuse No. 19 and retest system. If resistance is
more than 5 ohms, repair circuit No. 785 (Black/Light Green wire) for
open and retest system.
- To check circuit No. 489 (Pink/Black wire) for power, disconnect
GEM connector C234. Measure voltage from ground to GEM connector C234,
pin No. 22 (Pink/Black wire). See Fig 2
. If battery voltage
is present, go to step 9). If battery voltage is not present, go to
next step.
- To check circuit No. 489 (Pink/Black wire) for short to ground,
remove fuse No. 21 (10-amp) from fuse panel. Measure resistance
between ground and GEM connector C234, pin No. 22 (Pink/Black wire).
See Fig 2
. If
resistance is less than 10 k/ohms, repair circuit No. 489 (Pink/Black
wire) for short to ground. Replace fuse No. 21 and retest system. If
resistance is more than 10 k/ohms, go to next step.
- To check power supply to fuse No. 21, remove fuse No. 21
(10-amp) from fuse panel. Measure voltage from ground to fuse No. 21
input cavity. If battery voltage is present, go to next step. If
battery voltage is not present, repair electrical supply to fuse No.
21, replace fuse and retest system.
- To check circuit No. 489 (Pink/Black wire) for open, measure
resistance between GEM connector C234, pin No. 22 and output cavity of
fuse No. 21. See Fig 2
. If resistance is 5
ohms or less, replace fuse No. 21 and retest system. If resistance is
more than 5 ohms, repair circuit No. 489 (Pink/Black wire) for open
and retest system.
- To check circuit No. 397 (Black/White wire) for open, measure
resistance at GEM connector C233, pins No. 25 (Black/White wire), No.
26 (Black/White wire) and GEM connector C234, pin No. 15 (Black/White
wire). If resistance is less than 5 ohms, go to self test diagnostics
for Generic Electronic Module (GEM). See
MODULE COMMUNICATIONS NETWORK
article and retest system. If resistance is more
than 5 ohms, repair circuit No. 397 (Black/White wire) for open and
retest system.
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.