Test J: Powertrain Control Module (Pcm) Does Not Respond To NGS Tester
WARNING: This page is about a different car, the 1999 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If test results indicate PCM is faulty, always check for any engine performance related Diagnostic Trouble Codes (DTCs) prior to replacing PCM. If any DTCs are present, service DTCs as necessary and retest. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
- Turn ignition switch to LOCK position. Disconnect PCM harness connector located in engine compartment on left side of firewall. Inspect harness connector for loose, damaged or corroded terminals. Repair harness connector as necessary and retest system for normal operation. If harness connector is okay, reconnect harness connector. Turn ignition switch to RUN position. Perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM. If NGS tester indicates PCM: NO RESPONSE ON CKT 914 (BUS +), go to next step. If NGS tester does not indicate PCM: NO RESPONSE ON CKT 914 (BUS +), go to step 4.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect PCM harness connector. Measure resistance in Tan/Orange wire between terminal No. 16 at PCM harness connector and terminal No. 2 at Data Link Connector (DLC). See Figure and Fig 1 . If resistance is less than 5 ohms, replace PCM and retest system for normal operation. If resistance is 5 ohms or greater, go to next step.
- Disconnect 76-pin harness connector C201 located behind left side of instrument panel. See Figure. Inspect harness connector for loose, damaged or corroded terminals. Repair harness connector as necessary and retest system for normal operation. If harness connector is okay, measure resistance in Tan/Orange wire between terminal No. 59 at harness connector C201 and terminal No. 2 at DLC. See Figure and Figure . If resistance is less than 5 ohms, repair open in Tan/Orange wire between PCM harness connector and harness connector C201. Retest system for normal operation. If resistance is 5 ohms or greater, repair open in Tan/Orange wire between harness connector C201 and DLC. Retest system for normal operation.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect PCM harness connector. Measure resistance in Pink/Light Blue wire between terminal No. 15 at PCM harness connector and terminal No. 10 at DLC. See Figure and Fig 1 . If resistance is less than 5 ohms, replace PCM and retest system for normal operation. If resistance is 5 ohms or greater, go to next step.
- Disconnect 76-pin harness connector C201 located behind left side of instrument panel. See Figure. Inspect harness connector for loose, damaged or corroded terminals. Repair harness connector as necessary and retest system for normal operation. If harness connector is okay, measure resistance in Pink/Light Blue wire between terminal No. 60 at harness connector C201 and terminal No. 10 at DLC. See Figure and Figure . If resistance is less than 5 ohms, repair open in Pink/Light Blue wire between PCM harness connector and harness connector C201. Retest system for normal operation. If resistance is 5 ohms or greater, repair open in Pink/Light Blue wire between harness connector C201 and DLC. Retest system for normal operation.