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.
- Remove fuse No. 23 from fuse panel. See Fig 1 . Measure resistance between output pin (right side) of fuse No. 23 and ground. While observing ohmmeter, resistance should start at more than one M/ohm and drop steadily to less than 3 k/ohms. If resistance is as specified, go to step 7). If resistance is not as specified, go to next step.
- If resistance in step 1) read less than 10 ohms, go to step 4). If resistance was more than 10 ohms, go to next step.
- Remove GEM from fuse junction box. See Fig 2 . Disconnect and reconnect ohmmeter as in step 1). If resistance is more than one M/ohm (may drop steadily to less than 3 k/ohms), replace GEM and retest. If resistance is not more than one M/ohm, go to next step.
- Disconnect GEM connector C4. See Fig 5 . Measure resistance between output side of fuse No. 23 and ground. If resistance is less than 10 k/ohms, replace fuse junction panel and retest. If resistance is more than 10 k/ohms, reconnect GEM connector and go to next step if equipped with either passive anti-theft or remote anti-theft. If equipped with neither anti-theft system, reconnect GEM connector and go to step 7).
- If equipped with Passive Anti-Theft System (PATS), disconnect PATS module connector located under center of dashboard. Disconnect and reconnect ohmmeter as in step 1). If resistance reads more than one M/ohm and drops steadily to less than 3 k/ohms, replace PATS module and retest. If resistance value differs, go to next step.
- If equipped with Remote Anti-Theft Personality (RAP), disconnect RAP module connector located under center of dashboard. Disconnect and reconnect ohmmeter as in step 1). If resistance reads more than one M/ohm, replace RAP module and retest. If resistance value differs, repair circuit No. 1001 (White/Yellow wire) for short to ground and repeat test.
- Disconnect GEM connector C2. See Fig 3 . Measure resistance from ground to GEM connector C2, pins No. 14 and 25 (Black wire). If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair both circuit No. 57 (Black wire) for opens or high resistance and retest.
- Disconnect GEM connector C4. See Fig 5 . Measure resistance from ground to GEM connector C4, pin No. 12 (Black/White wire). If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair circuit No. 570 (Black/White wire) for open or high resistance and retest.
- Disconnect GEM connector C3. See Fig 4 . Turn ignition switch to RUN position. Measure voltage between GEM connector C3, pin No. 14 and ground. If battery voltage is present, go to step 11). If voltage is not present, go to next step.
- Remove fuse No. 12. See Fig 1 . Measure resistance across fuse. If fuse tests okay, repair circuit No. 640 (Red/Yellow wire) for open and retest. If fuse is blown, repair circuit No. 640 (Red/Yellow wire) for short to ground, replace fuse and retest.
- Measure resistance between ground and GEM connector C4, pin No. 22, circuit No. 938 (Black/Light Green wire). See Fig 5 . If resistance is less than 5 ohms, trace, test and repair module communications network circuit No. 70 (Light Blue/White wire). See WIRING DIAGRAMS . If resistance is more than 5 ohms, repair circuit No. 938 (Black/Light Green wire).