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

WARNING: This page is about a different car, the 2000 Mercury Mountaineer and 2000 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: With ignition on, voltage will be present 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. Repair scan tool connector as necessary and retest system for normal operation. If connector is okay, go to next step.
  2. Turn ignition off. Inspect Data Link Connector (DLC) for physical damage, bent terminals or corrosion. Pay particular attention to terminal No. 7 (Light Blue/White wire). Repair connector as necessary and retest system for normal operation. If connector is okay, go to next step.
  3. Ensure ignition is off. Disconnect GEM/CTM 26-pin connector C280. Measure resistance of Light Blue/White wire between GEM/CTM connector C280 terminal No. 25 and DLC terminal No. 7. See Figure and Figure . If resistance is 5 ohms or more, repair open in Light Blue/White wire between DLC and GEM/CTM. Retest system for normal operation. If resistance is less than 5 ohms, connect GEM/CTM connector C280 and go to next step.
  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.
    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 connector C212 located at left corner of instrument panel, near cowl panel grommet. See Figure. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, 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 and/or DSM, go to step  11.
  6. Turn ignition off. Reconnect in-line connector C212. Disconnect 40-pin bulkhead connector C148, located at left rear of engine compartment. See Figure. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, go to step  22.
  7. Turn ignition off. Reconnect bulkhead 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 connector C2000. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace ARC module and retest system for normal operation.
  9. Turn ignition off. Reconnect ARC module connector C2000. Disconnect GEM/CTM 26-pin connector C280. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace GEM/CTM and retest system for normal operation.
  10. Turn ignition off. Reconnect GEM/CTM connector C280. Deactivate air bag system. See appropriate AIR BAG RESTRAINT SYSTEMS article. Disconnect Restraint Control Module (RCM) 26-pin connector C232. Turn ignition on. 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 both readings indicate voltage, replace RCM and retest system for normal operation. If either reading indicates no voltage, repair Light Blue/White wire between DLC and RCM, GEM/CTM, ARC module, female half of connector C148 or female half of connector C212. Retest system for normal operation.
  11. Turn ignition off. Reconnect in-line 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 connector C336. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace RAP module and retest system for normal 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 off. Disconnect PAM 26-pin connector. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace PAM and retest system for normal 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 off. Disconnect DSM 22-pin connector C337. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace DSM and retest system for normal operation.
  17. Turn ignition off. Disconnect in-line 12-pin connector C346, located under rear of driver's seat. Turn ignition on. 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 either reading indicates no voltage, repair Light Blue/White wire between male half of in-line connector C212, female half of in-line connector C346 (if equipped with DSM), PAM connector C440 (if equipped) and RAP module connector (if equipped). Retest system for normal operation. If both readings indicate voltage, repair Light Blue/White wire between make half of in-line connector C346 and DSM connector C337. Retest system for normal operation.
  18. Turn ignition off. Reconnect in-line connector C212. Disconnect RAP module 26-pin connector C336. Turn ignition on. 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 either reading indicates no voltage, repair Light Blue/White wire between male half of in-line connector C212 and RAP module connector C336. Retest system for normal operation. If both readings indicate voltage, replace RAP module and retest system for normal operation.
  19. Turn ignition off. Reconnect in-line connector C212. Disconnect PAM 26-pin connector C440. Turn ignition on. 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 either reading indicates no voltage, repair Light Blue/White wire between male half of in-line connector C212 and PAM connector C440. If both readings indicate voltage, replace PAM and retest system for normal operation.
  20. Turn ignition off. Reconnect in-line connector C212. Disconnect DSM 22-pin connector C337. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace DSM and retest system for normal operation.
  21. Turn ignition off. Disconnect in-line connector C346, located under rear of driver's seat. Turn ignition on. 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 either reading indicates no voltage, repair Light Blue/White wire between male half of in-line connector C212 and female half of in-line connector C346. Retest system for normal operation. If both readings indicate voltage, repair Light Blue/White wire between male half of in-line connector C346 and DSM connector C337. Retest system for normal operation.
  22. Turn ignition off. Reconnect 40-pin bulkhead connector C148. Disconnect 4WABS module 25-pin connector. Turn ignition on. 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 either reading indicates no voltage, go to next step. If both readings indicate voltage, replace 4WABS module and retest system for normal operation.
  23. Turn ignition off. Disconnect in-line 12-pin connector C140 located near 4WABS module. Turn ignition on. 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 either reading indicates no voltage, repair Light Blue/White wire between male half of in-line connector C148 and male half of in-line connector C140. Retest system for normal operation. If both readings indicate voltage, repair Light Blue/White wire between female half of in-line connector C140 and 4WABS module. Retest system for normal operation.
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