1. Check for continuity between ECM/PCM connector terminal A21 and body ground.

Is there continuity?

YES | - | Repair short in the wire between ECM/PCM (A21) and the MAP sensor, the APP sensor, the input shaft (mainshaft) speed sensor (A/T).■
NO | - | Update the ECM/PCM if it does not have the latest software, or substitute a known-good, ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM / PCM .■