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Test K: No Module/Network Communication - ISO 9141 Network

WARNING: This page is about a different car, the 2001 Mercury Mountaineer and 2001 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: With ignition on, voltage will exist at Data Link Connector (DLC) terminal No. 7 (Light Blue/White wire). This is the International Standards Organization (ISO) 9141 diagnostic communications network circuit.
  1. Inspect NGS tester connector for loose, damaged or corroded terminals. Pay particular attention to scan tool terminal No. 7. If connector is okay, go to next step. If connector is damaged, repair scan tool connector as necessary and recheck system operation.
  2. Turn ignition switch to LOCK position. Inspect Data Link Connector (DLC) for physical damage, bent terminals or corrosion. Pay particular attention to terminal No. 7 (Light Blue/White wire). If connector is okay, go to next step. If connector is damaged, repair connector as necessary and recheck system operation.
  3. Ensure ignition is off. Disconnect Generic Electronic Module/Central Timer Module (GEM/CTM) 26-pin harness connector C280. Measure resistance of Light Blue/White wire between GEM/CTM harness connector C280 terminal No. 25 and DLC terminal No. 7. See Figure and Figure . If resistance is less than 5 ohms, connect GEM/CTM harness connector C280 and go to next step. If resistance is 5 ohms or more, repair open in Light Blue/White wire between DLC and GEM/CTM harness connector C280. Recheck system operation.
  4. If vehicle is equipped with a Remote Anti-Theft Personality (RAP) module, Parking Aid Module (PAM) or a Driver Seat Module (DSM), go to next step. If vehicle is not equipped with a RAP module, PAM or a DSM, go to step  6.
    5. NOTE: If there is a short to ground in Light Blue/White wire, then zero volts will be measured between DLC terminals No. 7 and 4. If there is a short to power in Light Blue/White wire, then zero volts will be measured between DLC terminals No. 7 and 16.
  5. Disconnect 84-pin in-line harness connector C212, located at left corner of instrument panel, near cowl panel grommet. See Figure. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If no voltage exists in either case, go to next step. If any voltage exists at either or both cases, proceed as follows:
    • If vehicle is equipped with RAP module only, go to step  18.
    • If vehicle is equipped with PAM only, go to step  19.
    • If vehicle is equipped with DSM only, go to step  20.
    • If vehicle is equipped with a combination of RAP module, PAM or DSM, go to step  11.
    6. NOTE: If there is a short to ground in Light Blue/White wire, then zero volts will be measured between DLC terminals No. 7 and 4. If there is a short to power in Light Blue/White wire, then zero volts will be measured between DLC terminals No. 7 and 16.
  6. Turn ignition switch to LOCK position. Reconnect in-line harness connector C212 (if disconnected). Disconnect 40-pin bulkhead harness connector C148, located at left rear of engine compartment. See Figure. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, go to step  22.
  7. Turn ignition switch to LOCK position. Reconnect bulkhead harness connector C148. If vehicle is equipped with a Air Suspension Control (ARC) module, go to next step. If vehicle is not equipped with a ARC module, go to step  9.
  8. Disconnect ARC module Gray 16-pin harness connector C2000. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, replace ARC module and recheck system operation.
  9. Turn ignition switch to LOCK position. Reconnect ARC module harness connector C2000 (if disconnected). Disconnect GEM/CTM 26-pin harness connector C280. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, replace GEM/CTM and recheck system operation.
  10. Turn ignition switch to LOCK position. Reconnect GEM/CTM harness connector C280. Deactivate air bag system. See appropriate AIR BAG RESTRAINT SYSTEMS article. Disconnect Restraint Control Module (RCM) 26-pin harness connector C232. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage exists in both measurements, replace RCM and recheck system operation. If voltage does not exist in either measurement, repair Light Blue/White wire between DLC and RCM, GEM/CTM, ARC module, female half of harness connector C148 or female half of harness connector C212. Recheck system operation.
  11. Turn ignition switch to LOCK position. Reconnect in-line harness connector C212. Check if vehicle is equipped with Remote Anti-Theft Personality (RAP) module. If vehicle is equipped with RAP module, go to next step. If vehicle is not equipped with RAP module, go to step  13.
  12. Disconnect RAP module 26-pin harness connector C336. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, replace RAP module and recheck system operation.
  13. Check if vehicle is equipped with Parking Aid Module (PAM). If vehicle is equipped with PAM, go to next step. If vehicle is not equipped with PAM, go to step  15.
  14. Turn ignition switch to LOCK position. Disconnect PAM 26-pin harness connector C440. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in either or both measurement(s), replace PAM and recheck system operation.
  15. Check if vehicle is equipped with Driver Seat Module (DSM). If vehicle is equipped with DSM, go to next step. If vehicle is not equipped with DSM, go to step  17.
  16. Turn ignition switch to LOCK position. Disconnect DSM 22-pin harness connector C337. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, replace DSM and recheck system operation.
  17. Turn ignition switch to LOCK position. Disconnect in-line 12-pin harness connector C346, located under rear of driver's seat. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, repair Light Blue/White wire between male half of in-line harness connector C212, female half of in-line harness connector C346 (if equipped with DSM), PAM harness connector C440 (if equipped) and RAP module harness connector (if equipped). Recheck system operation. If voltage exists in both measurements, repair Light Blue/White wire between male half of in-line harness connector C346 and DSM. Recheck system operation.
  18. Turn ignition switch to LOCK position. Reconnect in-line harness connector C212. Disconnect RAP module 26-pin harness connector C336. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exists in either measurement, repair Light Blue/White wire between male half of in-line harness connector C212 and RAP module harness connector C336. Recheck system operation. If voltage exists in both measurement, replace RAP module and recheck system operation.
  19. Turn ignition switch to LOCK position. Reconnect in-line harness connector C212. Disconnect PAM 26-pin harness connector C440. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, repair Light Blue/White wire between male half of in-line harness connector C212 and PAM. If voltage exists in both measurements, replace PAM and recheck system operation.
  20. Turn ignition switch to LOCK position. Reconnect in-line harness connector C212. Disconnect DSM 22-pin harness connector C337. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, go to next step. If voltage exists in both measurements, replace DSM and recheck system operation.
  21. Turn ignition switch to LOCK position. Disconnect in-line harness connector C346, located under rear of driver's seat. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in both measurements, repair Light Blue/White wire between male half of in-line harness connector C212 and female half of in-line harness connector C346. Recheck system operation. If voltage exists in both measurements, repair Light Blue/White wire between male half of in-line harness connector C346 and DSM. Recheck system operation.
  22. Turn ignition switch to LOCK position. Reconnect 40-pin bulkhead harness connector C148. Disconnect 4WABS module 25-pin harness connector C186. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). See Figure. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in both measurements, go to next step. If voltage exists in both measurements, replace 4WABS module and recheck system operation.
  23. Turn ignition switch to LOCK position. Disconnect in-line 12-pin harness connector C140 located near 4WABS module. Turn ignition switch to RUN position. Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 16 (Orange wire). Measure voltage between DLC terminals No. 7 (Light Blue/White wire) and No. 4 (Black wire). If voltage does not exist in either measurement, repair Light Blue/White wire between male half of in-line harness connector C148 and male half of in-line harness connector C140. Recheck system operation. If voltage exists in both measurements, repair Light Blue/White wire between female half of in-line harness connector C140 and 4WABS module. Recheck system operation.
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