No Communication With Engine Control Module/Powertrain Control Module: Testing

1. Turn the ignition switch to LOCK position. Locate PCM. See POWERTRAIN CONTROL MODULE LOCATION  under SELF-DIAGNOSTIC SYSTEM. Check PCM connector C-110 for loose, damaged or corroded terminals. See Figure . If faulty connections are found, repair as necessary. If connections are okay, go to next step.
2. Check for loose, damaged or corroded terminals in intermediate connectors C-105 and C-02. If problem does not exist, go to next step. If faulty connections are found, repair as necessary. Recheck communication.
3. Check for open or short to ground between DLC terminal No. 7 (Orange/Blue wire) and PCM connector C-110 terminal No. 85 (Orange/White wire). See Fig 1 and Figure . If problem does not exist, check power to PCM. See ECM/PCM under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING article. If problem exists, repair Orange/White wire. Recheck communication.

Fig 1: Identifying Data Link Connector Serial Data Circuit

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.