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Test G: Message Center Module (MCM) Does Not Respond To NGS Tester

WARNING: This page is about a different car, the 1998 Lincoln Mark VIII. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition off. Disconnect MCM 12-pin connector C246, located behind center of instrument panel, above radio. Inspect MCM connector for loose, damaged or corroded terminals. Repair connector as necessary and retest system for normal operation. If connector is okay, reconnect MCM connector. Turn ignition on. Perform data link diagnostic procedure. See DATA LINK DIAGNOSTIC TEST under COMMUNICATION NETWORK DIAGNOSTICS. If NGS tester indicates MCM: NO RESPONSE ON CKT 914 (BUS +) or MCM: NO RESPONSE ON CKT 915 (BUS -), go to next step. If NGS tester does not indicate MCM: NO RESPONSE ON CKT 914 (BUS +) or MCM: NO RESPONSE ON CKT 915 (BUS -), no problem is indicated at this time. Return to article that directed you here and continue diagnosis.
  2. If NGS tester indicated MCM: NO RESPONSE ON CKT 914 (BUS +) in step 1), go to next step. If NGS tester indicated MCM: NO RESPONSE ON CKT 915 (BUS -) in step 1), go to step 4).
  3. Turn ignition off. Disconnect MCM 12-pin connector C246. Disconnect NGS tester. Using an ohmmeter, measure resistance of Tan/Orange wire between terminal No. 5 at MCM connector C246 and terminal No. 2 at Data Link Connector (DLC). See Figure and Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair Tan/Orange wire between MCM connector C246 and DLC. Retest system for normal operation.
  4. Turn ignition off. Disconnect MCM 12-pin connector C246. Disconnect NGS tester. Using an ohmmeter, measure resistance of Pink/Light Blue wire between terminal No. 4 at MCM connector C246 and terminal No. 10 at Data Link Connector (DLC). See Figure and Fig 1. If resistance is less than 5 ohms, replace MCM and retest system for normal operation. If resistance is 5 ohms or more, repair Pink/Light Blue wire between MCM connector C246 and DLC. Retest system for normal operation.
Fig 1: Identifying MCM Connector C246 Terminals
G98C01703Courtesy of FORD MOTOR CO.
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