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Pinpoint Test A - No Communication With Generic Electronic Module (Gem)

WARNING: This page is about a different car, the 1997 Mercury Sable and 1997 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove fuse No. 23 (5-amp) from fuse junction panel. Measure resistance between output (right side) pin of fuse No. 23 and ground. If resistance starts at greater than one megohm and drops steadily to less than 3 k/ohms, go to step 7). If resistance is not as described, go next step.
  2. Using same setup as in step 1), recheck resistance. If resistance is 10 ohms or greater, go to next step. If resistance is less than 10 ohms, go to step 4).
  3. Remove Generic Electronic Module (GEM) from fuse junction panel. Disconnect then reconnect ohmmeter as in step 1). If resistance starts at greater than one megohm (it may drop steadily to less than 3 k/ohms), replace GEM and retest system. If resistance is not as described, go to next step.
  4. Disconnect 27-pin fuse junction panel connector C247 (located on left side of instrument panel fuse junction panel). Measure resistance between output (right side) pin of fuse No. 23 and ground. If resistance is less than 10 k/ohms, replace fuse junction panel and retest system. If resistance is 10 k/ohms or greater, reconnect fuse junction panel connector C247 and, if equipped with Passive Anti-Theft System/Remote Anti-Theft Personality System (PATS/RAP), go to next step. Go to step 7) if not equipped with PATS/RAP.
  5. Disconnect 16-pin PATS module connector C242 (located behind right side of instrument cluster). Disconnect and reconnect ohmmeter as in step 1). If resistance starts at greater than one megohm and drops steadily to less than 3 k/ohms, replace PATS module and retest system. If resistance is not as described, go next step.
  6. Disconnect RAP module connector C254. Disconnect and reconnect ohmmeter as in step 1). If resistance is greater than one megohm, replace RAP module and retest system. Is resistance is one megohm or less, repair short to ground in circuit No. 1001 (White/Yellow wire). Retest system.
  7. Disconnect GEM connector C248. Measure resistance between ground and GEM connector C248, terminals No. 14 (Black wire) and No. 26 (Black wire). See Figure . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms on either or both circuits No. 57 (Black wire), repair wire(s) as necessary and retest system.
  8. Disconnect GEM connector C223. Measure resistance between ground and GEM connector C223, terminal No. 12 (Black/White wire). See Figure . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms on circuit No. 570 (Black/White wire), repair wire as necessary and retest system.
  9. Disconnect GEM connector C236. Turn ignition on. Measure voltage at GEM connector C236 terminal No. 14 (Red/Yellow wire). See Figure . If battery voltage does not exist, go to next step. If battery voltage exists, go to step 11).
  10. Remove fuse junction panel fuse No. 12 (5-amp). Check fuse condition. If fuse is good, repair open in circuit No. 640 (Red/Yellow wire) and retest system. If fuse is faulty, repair short to ground in circuit No. 640 (Red/Yellow wire) and retest system.
  11. Measure resistance between ground and GEM connector C223, terminal No. 22 (Black/Light Green wire). See Figure . If resistance is 5 ohms or less, see MODULE COMMUNICATIONS NETWORK article. If resistance is greater than 5 ohms on circuit No. 938 (Black/Light Green wire), repair wire as necessary and retest system.
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